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S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
S 8000 operation manual
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S 8000 operation manual

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  • 1. INSTRUCTION MANUAL S-8000 SERIES HIGH RESOLUTION FEB CD MEASUREMENT SEM (SYSTEM SECTION) (V11 ~) Please read through this manual carefully and store it in a safe place. · Before using the instrument, read the safety instructions and precautions carefully. · Keep this manual in a safe place nearby so it can be referred to whenever needed.Copyright ã Hitachi, Ltd. 1998. All rights reserved. Printed in Japan. Part No. 567-8220
  • 2. Notice:1. Information contained in this document is subject to change without notice for improvement.2. No part of this manual may be reproduced or transmitted in any form or by any means without the express written permission of Hitachi.3. Hitachi assumes no liability for any direct, indirect, or consequential damages arising from use not described in this manual.4. This document does not provide any warranty or permission for industrial properties or any rights to grant license lawfully and without infringement.
  • 3. FOREWORDThank you very much for purchasing the Hitachi S-8000 Series High Resolution FEB CDMeasurement SEM. It is designed for carrying out circuit pattern inspection and dimensioncontrol in evaluation of semiconductor device fabrication processes. Please read throughthis manual carefully for long-lasting trouble-free operation of the instrument. HOW TO USE THIS INSTRUCTION MANUAL• The instruction manuals for the S-8000 Series High Resolution FEB CD Measurement SEM include the following three volumes; System Section, Operating Section and Window Operation Section. This volume of instruction manual is System Section.• The System Section covers the installation requirements, names of parts of instrument, functions and operating principles, file system, coordinate schemes, start/stop of instrument operation, troubleshooting, maintenance, safety precautions, etc.• The Operating Section presents the instrument operating procedures, file creating procedures, optional function control procedures, and possible causes of error messages and remedial procedures.• The Window Operation Section deals with the operational functions and procedures for windows displayed on the monitor.• Before attempting operation of the instrument, read the System Section first. Then, after you have acquired a basic knowledge of the instrument system, proceed to the Operating Section and Window Operation Section.• The maintenance and checkup procedures for ensuring normal operation of the instrument are described in the System Section. According to the periodic check list, carry out maintenance and inspection periodically as instructed.• This instruction manual contains descriptions of more than one instrument model, software version and optional function in some items. Check your instrument model, software version and optional functions incorporated, read the relevant descriptions.• This instruction manual covers the following models of S-8000 series. S-8000 series: S-8820/S-8620, S-8840/S8640 -1-
  • 4. GUARANTEEPeriod of GuaranteeOne year from the date of installation.Details of GuaranteeThe instrument will be repaired free of charge if it malfunctions due to a defect in manufacturewithin the period of guarantee and this is acknowledged by Hitachi.Unguaranteed ItemsThis guarantee will not be valid for the following failures and/or cases even during the period ofguarantee.· Failure due to use in improperly installed condition· Failure caused by erroneous use or improper repair· Failure attributable to movement or relocation after installation· Failure resulting from disassembly or modification by customer· Failure due to force majeure such as fire or earthquake· Consumables and parts limited in period of guarantee· The guarantee period of the electron source (tip) of S-8000 series is 6000 hours or nine months, whichever earlier, and is excluded from the one-year guarantee.· The guarantee period of the electron source (tip) of S-7800 is 4000 hours or six months, whichever earlier, and is excluded from the one-year guarantee.· Remarkably hastened corrosion of electric circuits and deterioration of optical elements due to corrosive gases (chlorine gas, etc.) contained in air.· When instrument is disposed of or resold without informing Hitachi.· When instrument is disassembled, modified or subjected to parts replacement without Hitachi’s approval, or re-installed without informing Hitachi. INSTALLATION AND AFTER-SALES SERVICEInstallation at delivery will be carried out by our installation engineers. For the installation, besure to refer to section 1. Installation at another place after delivery will be provided atcharge. To avoid possible trouble involved in relocation, be sure to consult your nearestHitachi service representative. And for service after the guarantee period, please consult usabout a maintenance & inspection contract. -2-
  • 5. SAFETY SUMMARY General Safety GuidelinesBefore operating the instrument, read the following instructions carefully:• Follow all the operating procedures provided in this manual.• Pay special attention to and follow all the hazard warnings on the instrument and in the manual. Failure to do so can cause injury to yourself or damage to the instrument.• The hazard warnings which appear on the warning labels on the instrument or in the manual have one of the following alert headings consisting of an alert symbol and a signal word, DANGER, WARNING, or CAUTION. DANGER : indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury. WARNING : indicates a potentially hazardous situation which, if not avoided, can result in death or serious injury. CAUTION : indicates a hazardous situation which, if not avoided, will or can result in minor or moderate injury, or serious damage of product. : The alert symbol shown at left precedes every signal word for hazard warnings, and appears in safety related descriptions in the manual.The signal word ‘NOTICE’ is used to present warnings which are not directly related topersonal injury hazards.• Do not perform any operation or action in any way other than as provided in this manual. When in doubt, call the designated field engineer.• Keep in mind that the hazard warnings in this manual or on the instrument cannot cover every possible case, as it is impossible to predict and evaluate all circumstances beforehand. Be alert and use your common sense. SAFETY - 1
  • 6. WARNING• Voltages up to 100 V AC and 10 kV DC are used inside this instrument. Do not touch inside or you may receive an electric shock.• Do not remove the covers of main column unit, control unit or power unit while the instrument power is turned on. There is a danger of fatal or serious injury due to electric shock.• Anyone working on the electrical part of the system should follow the correct lock-out tag-out procedures for that location.• Electrical hazards can occur if lock-out tag-out procedures are not followed. CAUTION Beware of injury• There is a possibility of injury while the wafer transfer mechanism is operating.• Do not touch inside the cassette loader with the power turned on. SAFETY - 2
  • 7. WARNING 1. Beware of invisible laser • An invisible laser is used in this instrument. Looking directly at the laser beam or coming into contact with it may result in injury. • Upon opening the cover of the Z sensor, an interlock mechanism works to prevent oscillation of the laser. But before opening this cover, be sure to turn OFF either the SEM power switch at the top of the display unit or the Z sensor key switch. 2. This instrument is equipped with the laser device shown below. Under normal operation, there is no potential for accidents since it is not required to take out the laser device. To ensure safety, however, be sure to observe the following precautions. (1) Never touch the laser beam emitting/receiving part mounted in the column unit. (2) Never touch the laser drive circuit mounted on the specimen chamber. (3) When the laser device has reached the end of its service life, refer replacement/adjustment servicing to Hitachi service personnel. Do not tamper with the laser device. Remember that other optical parts also are not user-serviceable. Purpose Inside Designation Wavelength Output Class of Output InstrumentSemiconductor 780 nm (red) 5 mW max. Class 3B Detection oflaser (3 to 500 mW) specimen height Conforming to ANSI Z136.1-1985 3. Never adjust or use the laser control function in a manner not specified in this instruction manual, or you might be exposed to the laser beam. SAFETY - 3
  • 8. WARNING • If a large amount of vaporized hexane (n-hexane) is inhaled, it may result in injury or breathing difficulty. • In a place where hexane is used, be sure to ventilate well and be careful not to inhale in a large amount. Also wear an antigas mask or the like if necessary. • Be careful not to ignite vaporized hexane because it may explode. • When hexane is used, be sure to ventilate the place well and dont use a flame in the vicinity. • If hexane is mistakenly swallowed or comes into contact with the skin or eyes, it may affect the nervous system in various ways such as paralysis of the senses, difficulty in walking, etc. due to stimulation. • When hexane is used, be sure to ventilate the place well, and depending on the conditions, use an air aspirator, protective goggles and protective gloves and clothes. CAUTION• Gazing at the CRT screen and/or operating the keyboard for long hours may result in fatigue or other ill effects.• The customer is recommended to establish work management standards and follow them. SAFETY - 4
  • 9. CAUTION ON DISPOSAL OF INSTRUMENT• Although at present the instrument does not use materials that will directly harm the environment, changes are apt to be made in relevant laws and/or regulations, so be sure to consult a qualified specialist when planning to dispose of the instrument. PRECAUTIONS ON USERange of application• The instrument is intended mainly for measuring and observing linewidths and patterns on semiconductors.Operator qualification• Operation should be conducted under the management of a technician who has undergone orientation at the facility specified by Hitachi.Caution on use and maintenance• For usage and maintenance of the instrument, use the specified procedure and avoid touching any place other than specified.Environmental requirements (installation conditions)• Follow the specified installation conditions.• Do not lift the instrument via its table when moving it.• When relocating the instrument, be sure to fasten the console with the brackets used at transportation.• Contact the sales agent for change of the installation place. Warning labels maintenance• Call your nearest Hitachi service representative. SAFETY - 5
  • 10. HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE C A U TI O N CAUTION HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE CAUTIONSAFETY - 6 A HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE CAUTION HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE HAZARDOUS VOLTAGE A L O A D - L O C K C H A MB E R HAZARDOUS VOLTAGE CAUTION CAUTION CAUTION M AI N C O N S O L E HAZARDOUS VOLTAGE Locations of Warning on Main Column Unit
  • 11. HAZARDOUS VOLTAGE DISPLAY CONSOLESAFETY - 7 MFC HAZARDOUS name plate VOLTAGE HAZARDOUS VOLTAGE (INSIDE) POWER SUPPLY CONSOLE BACK VIEW Locations of Warning Labels on Control Unit and Power Unit
  • 12. S-8000 SERIES HIGH RESOLUTION FEB CD MEASUREMENT SEM (SYSTEM SECTION) (V11~) CONTENTS1. INSTALLATION ......................................................................................................... 1–1 1.1 Installation Requirements ................................................................................. 1–1 1.1.1 General ................................................................................................. 1–1 1.1.2 Room Temperature and Humidity.......................................................... 1–2 1.1.3 Line Power Requirements ..................................................................... 1–2 1.1.4 Grounding ............................................................................................. 1–2 1.1.5 Gas Source ........................................................................................... 1–3 1.1.6 Stray Magnetic Field.............................................................................. 1–3 1.1.7 Vibration ................................................................................................ 1–4 1.1.8 External Power/Electric Field Noise....................................................... 1–4 1.1.9 Disturbance by Sound Waves ............................................................... 1–4 1.1.10 Physical Requirements (Installation space, entrance dimensions, floor conditions).................... 1–5 1.1.11 Power Capacitance ............................................................................... 1–10 1.1.12 Evacuation Duct for Oil Rotary Pump (option)........................................ 1–10 1.2 Items to Be Prepared by User........................................................................... 1–12 1.3 Power and Ground Wiring Connections............................................................ 1–132. FUNCTIONS.............................................................................................................. 2–1 2.1 Appearance of Instrument System.................................................................... 2–1 2.2 Specifications ................................................................................................... 2–2 2.2.1 Specifications of S-8840/S-8640 ........................................................... 2–2 2.2.2 Specifications of S-8820/S-8620.............................................................. 2–4 2.3 Main Column Units ........................................................................................... 2–6 2.3.1 General ................................................................................................. 2–7 2.3.2 Evacuation System................................................................................ 2–8 2.3.3 Evacuation Control (Manual) Panel ....................................................... 2–9 2.3.4 Auto Loader System.............................................................................. 2–15 2.3.5 Objective Movable Aperture Control ...................................................... 2–19 2.4 Display Unit ...................................................................................................... 2–20 2.4.1 Appearance of Display Unit ................................................................... 2–20 2.4.2 Functions............................................................................................... 2–20 2.5 Power Supply Unit ............................................................................................ 2–26 2.5.1 General ................................................................................................. 2–27 -i -
  • 13. CONTENTS (cont’d)3. PRINCIPLE OF MICROSCOPE INSTRUMENT......................................................... 3–1 3.1 Schottky Emission (SE) Electron Source .......................................................... 3–1 3.2 Electron Optical System ................................................................................... 3–2 3.2.1 Retarding Method.................................................................................. 3–2 3.2.2 Note on Retarding Method Operation.................................................... 3–3 3.3 Two-Stage Detection System (S-8840/S-8640) ................................................ 3-44. COMPUTER SYSTEM AND SOFTWARE ................................................................. 4–1 4.1 Computer System Configuration....................................................................... 4–15. FILES......................................................................................................................... 5–1 5.1 System Files ..................................................................................................... 5–1 5.2 User Files ......................................................................................................... 5–2 5.2.1 Hierarchical File Structure ..................................................................... 5–3 5.2.2 Handling of User Files ............................................................................. 5–46. COORDINATE SCHEMES ........................................................................................ 6–1 6.1 General............................................................................................................. 6–1 6.2 Stage Coordinate Scheme................................................................................ 6–1 6.3 Wafer Coordinate Scheme ............................................................................... 6–2 6.3.1 Chip Number and On-Chip Coordinates ................................................ 6–2 6.3.2 Wafer Coordinates ................................................................................ 6–3 6.4 Wafer Alignment............................................................................................... 6–4 6.5 Visual Field Shift in Each Coordinate Scheme .................................................. 6–67. STARTUP AND SHUTDOWN OF INSTRUMENT ..................................................... 7–1 7.1 Startup.............................................................................................................. 7–1 7.1.1 Usual Startup Procedure ....................................................................... 7–1 7.1.2 Startup from Complete Shutdown.......................................................... 7–3 7.1.3 Startup After Recovery from Power Failure or Emergency Stop............ 7–5 7.2 Shutdown of Instrument.................................................................................... 7–5 7.2.1 Normal Shutdown.................................................................................. 7–5 7.2.2 Complete Shutdown of Instrument ........................................................ 7–6 7.2.3 Shutdown at Power Failure.................................................................... 7–78. IMAGE ADJUSTMENT .............................................................................................. 8–1 8.1 Optical Microscope Image ................................................................................ 8–1 8.1.1 Adjustment of Optical Microscope (OM) Image ..................................... 8–1 8.1.2 Auto Adjustment of Optical Microscope (OM) Image ............................. 8–3 8.2 Condition Setting for SEM Image...................................................................... 8–4 - ii -
  • 14. CONTENTS (cont’d) 8.3 Axial Alignment of Electron Optics .................................................................... 8–5 8.3.1 Axial Alignment of Electron Optics......................................................... 8–5 8.3.2 Axial Alignment of Electron Gun (carried out by service engineers only) 8–6 8.3.3 Axial Alignment of Condenser Lens 1 and 2 (carried out by service engineers only) .................................................. 8–7 8.3.4 Axial Alignment of Objective Movable Aperture ..................................... 8–7 8.3.5 Axial Alignment Using Alignment 1........................................................ 8–8 8.3.6 Axial Alignment Using Alignment 2........................................................ 8–9 8.3.7 Axial Alignment of Stigmator Coil .......................................................... 8–9 8.3.8 Astigmatism Correction ......................................................................... 8–9 8.3.9 Focusing................................................................................................ 8–10 8.3.10 Saving/Loading of SEM Condition Memory ........................................... 8–12 8.3.11 Image Contrast and Brightness ............................................................. 8–129. TROUBLESHOOTING............................................................................................... 9–1 9.1 Evacuation System Abnormalities..................................................................... 9–3 9.2 Abnormal Specimen Stage/Loader ................................................................... 9–4 9.3 Abnormal SEM Image....................................................................................... 9–6 9.3.1 Abnormal Emission Current................................................................... 9–6 9.3.2 Absence of Image on CRT .................................................................... 9–6 9.3.3 Noisy Image .......................................................................................... 9–7 9.4 Abnormal Optical Microscope (OM) Image ....................................................... 9–8 9.4.1 Absence of OM Image........................................................................... 9–8 9.5 Display Unit Fails .............................................................................................. 9–8 9.6 Software Error ................................................................................................. 9–8 9.6.1 How to Save Log Data onto Hard Disk (HD).......................................... 9–9 9.6.2 How to Output Log Data onto Floppy Disk............................................. 9–9 9.6.3 Restart After Software Error .................................................................. 9–1010. MAINTENANCE......................................................................................................... 10–1 10.1 Consumables and Spare Parts ......................................................................... 10–1 10.1.1 Consumables ........................................................................................ 10–1 10.1.2 Spare Parts ........................................................................................... 10–2 10.2 Cautions on Maintenance ................................................................................. 10–2 10.3 Periodic Inspection ........................................................................................... 10–3 10.3.1 Evacuation System................................................................................ 10–4 10.3.2 Replacement of Objective Movable Aperture......................................... 10–5 10.3.3 Check Lists............................................................................................ 10–7 10.3.4 Rotary Vacuum Pump (option) .............................................................. 10–11INDEX................................................................................................................................. I-1 - iii -
  • 15. 1.1.1 1. INSTALLATION1.1 Installation RequirementsIf the following installation requirements are not satisfied, consult Hitachi about countermeasures.1.1.1 GeneralFor installation of this instrument, avoid the conditions listed below. Refer to 1.1.6 through1.1.9 for details.(1) Room located in the vicinity of transformer substation(2) Room in the vicinity of elevator(3) Location near large-power consuming equipment (e.g. electric furnace) or its power supply(4) Location near spark discharge source or high-frequency apparatus(5) Room filled with gas which may corrode metals(6) Place exposed to strong draft(7) Location subjected to severe vibrations(8) Use of ground line common to other electrical equipment(9) Location near radio or sound wave source 1-1
  • 16. 1.1 Installation Requirements1.1.2 Room Temperature and HumidityAt a place where this instrument is installed, maintain the following environmental conditionseven when it is not operated.(1) Room temperature •••••20 to 25°C Temperature fluctuation should be less than 2°C during operation of the instrument.(2) Humidity (RH) •••••60% or less The instrument should be operated in an air-conditioned room.1.1.3 Line Power Requirements(1) 100 V AC, 5 kVA, 50/60 Hz, 1 phase (Maximum power: 100 V AC, 50 A) It is required to supply power continuously. Even if the instrument is left unused for a long time, evacuation should be performed continuously. Fluctuation in line power voltage should be within a range of ±10% with respect to 100 V AC level. NOTICE: For a period of 24 hours, power voltage fluctuation should be within a range of ±5%, and no abrupt fluctuation on the order of seconds is allowable.(2) Momentary power interruption should be restricted to less than one cycle at 100% DIP.(3) The power supply unit of this instrument should be located within a distance of 10 meters from the power distribution panel on wall (the input AC power cord is 10 meters long). The solderless terminal is equipped at the end of the input AC power cord. (Solderless terminal size: 8.6 mm in inside diameter, 16 mm in outside diameter)(4) On the power distribution panel, be sure to use a circuit breaker dedicated for this instrument. It is required to supply primary input power protection for isolation transformer not to exceed 250% (12,500 VA for S-8000 series, S-7800) of power ratings.1.1.4 GroundingConnect this instrument with a grounding terminal having ground resistance of less than100 ohms. The grounding terminal must not be common to other electrical equipment, i.e. anexclusive grounding connection to earth should be provided. 1-2
  • 17. 1.1.51.1.5 Gas Source(1) N2 Gas Source (for leak) Gas pressure : 400 to 880 kPa (4 to 9 kgf/cm2), with 0.01 µm filter Outside diameter of connecting tube : 6 mm(2) Compressed Air Source (for valve drive) Air pressure : 600 to 880 kPa (6 to 9 kgf/cm 2) Outside diameter of connecting tube : 6 mm(3) Vacuum Source (for auto loader) Vacuum pressure : P = 13 to 40 kPa (100 to 300 Torr) Diameter of connecting tube: 6 mm1.1.6 Stray Magnetic FieldNo image trouble will occur when the stray magnetic field conditions shown in Tables 1-1 aresatisfied at the instrument installation place. Before proceeding to installation, check the straymagnetic field conditions as required. Make sure that the conditions shown in these tables aresatisfied.If there is a large-sized magnet clutch or power cable for other equipment in the vicinity of thisinstrument, abrupt variation in current or magnetic field may take place. Avoid installing thisinstrument at such a location.If the instrument is installed in an environment having intense stray magnetic field, the scanningelectron beam is forced to tremble due to the magnetic field, causing abnormal expansion,shrinkage, distortion, unintentional shift, or whisker noise in imaging. These adverse effectsoccur differently depending on whether the frequency component of stray magnetic field issynchronous with power current frequency or not. Therefore, the allowable value of straymagnetic field component synchronous with power current frequency is different from that ofstray magnetic field component asynchronous with power current frequency (DC magnetic fieldvariation).(1) Adverse effects due to stray magnetic field component synchronous with power frequency, and its maximum allowable value: The stray magnetic field component synchronous with power frequency appears as image distortion or deformation on the CRT display. This is because the electron beam is scanned in synchronization with the power frequency. The maximum allowable value of stray magnetic field component synchronous with power frequency is specified so that no adverse effect will be given to CD measurement reproducibility. 1-3
  • 18. 1.1 Installation Requirements(2) Adverse effects due to stray magnetic field component asynchronous with power frequency, and its maximum allowable value: The stray magnetic field component asynchronous with power frequency affects imaging directly. That is, movement of the electron beam due to variation in external magnetic field appears as unintentional shift or whisker noise in imaging. Even slight variation in external magnetic field may result in conspicuous irregularity of image. The maximum allowable value of stray magnetic field component asynchronous with power frequency is specified so that CD measurement reproducibility will not be affected by image shift or whisker noise due to stray magnetic field.1.1.7 VibrationBefore installing this instrument, measure floor vibration at site. No image trouble will occurwhen the vibration conditions shown in Tables 1-2 and 1-4 are satisfied.If the instrument is installed on the first floor of a reinforced-concrete (steel-framed-concrete)building, the performance of instrument will not be degraded by external vibration as long asvibration sources such as heavy-duty machine tools or transportation facilities (e.g. electric car)are not operated nearby.Check the vibration conditions at site before installation (or on receiving order) as required.Make sure that the conditions shown in these tables are satisfied. (As to vibrationmeasurement at site, consult Hitachi sales representative.)1.1.8 External Power/Electric Field NoiseTo prevent a possible trouble in imaging, check for any interference noise source in selection ofan installation place for this instrument. If such an interference noise source as shown in Table1-5 or its power line is located nearby, it will cause poor imaging. Also, a desirable image maynot be attained if an interference noise source even located at a distance consumes large power.Besides, if a device located nearby or its power line uses a different commercial powerfrequency from that for this instrument, the power-frequency-synchronized scanning will bedisturbed. Remember this in selection of an installation place.1.1.9 Disturbance by Sound WavesSound waves (vibrations of air) will adversely affect this instrument and may cause imagetrouble. To prevent this, make sure before installation that a sonic disturbance source is notlocated nearby.If there is any sonic disturbance source in the vicinity of the installation place, then check fornoise level. When conversation is possible in a usual voice around the installation site, thenoise level is allowable. But if conversation is possible only in a loud voice due to abnormalnoise of equipment located nearby, sonic disturbance will occur in imaging.Allowable sound pressure: Less than 75 dB (in C characteristic) 1-4
  • 19. 1.1.101.1.10 Physical Requirements (Installation space, entrance dimensions, floor conditions)(1) Floor Space Required (excluding the space areas for operation, maintenance and power supply equipment) Approx. 3.0 m (W) ´ 2.2 m (D) recommended(2) Dimensions of Entrance 1.8 m (W) ´ 2.2 m (H) at least(3) Durability of Floor 2 Floor strength (kg/m ) Total weight of instruments installed in room (kg) 3 ³ 2 Floor area of room (m )(4) Installation Layout Refer to Figs. 1-1 through 1-3.(5) Maintenance Spaces for Instrument Be sure to leave the following maintenance spaces (including easy-to-open partitions). Main column unit : Front, rear and left-side space areas for maintenance Control unit : Front and rear space areas for maintenance Power supply unit : Front and rear space areas for maintenance Table 1-1 Allowable Stray Magnetic Field (At CD measurement) Stray Magnetic Stray Magnetic Field Field Component Component SEM Operating Conditions for CD Measurement Synchronous with Asynchronous with Power Frequency Power Frequency (AC magnetic field) (DC magnetic field Accelerating Observation Scanning Specimen *1, *2 variation) *3 Voltage Magnification Mode 0.3 mT or less 0.1 mT or less 800 V 40,000´ Resist L/S AVER mode, frame number 8 4 T: Tesla (10 gauss)Notes: *1. The components due to terrestrial magnetic field are excluded from the value indicated above. Terrestrial magnetic field in Japan: Horizontal magnetic component • • • 30 mT Vertical magnetic component • • • • • 35 mT *2. An effective value of AC component should be measured. *3. If DC magnetic field variation is 0.1 mT or less, it may be out of consideration when observing intensity-modulated images. 1-5
  • 20. 1.1 Installation Requirements Table 1-2 Allowable Vibration External vibration: No image trouble will occur if the following conditions are satisfied. (1) Oscillation frequency of less than 10 Hz Oscillation Frequency Amplitude 1 Hz 3 mm p-p max. 2 Hz 0.7 mm p-p max. 3 Hz 1.2 mm p-p max. 4 Hz 2 mm p-p max. 5 Hz 3 mm p-p max. 10 Hz 3.5 mm p-p max. NOTICE: 1. A sine wave should be measured in vibration measurement. In case of other than a sine wave, measurement should be made with each frequency component concentrated at a dominant frequency* level. 2. For vibration at extremely low frequency of less than 1 Hz, complete prevention is impossible with the vibration-isolating technology available at present. 3. In a frequency region of 2 Hz to 10 Hz, interpolation should be made through each allowable value point. 4. If floor vibration exceeds the allowable limit, please consult Hitachi (floor vibration that may cause any image trouble should be measured in advance). (2) Oscillation frequency exceeding 10 Hz If the dominant frequency of oscillation exceeds 10 Hz, please consult Hitachi.* Dominant frequency: Peak frequency upon subjecting the oscillation waveform to frequency analysis. 1-6
  • 21. 1.1.10 Table 1-3 External Noise Sources (Interference power/electric field noise sources) Possible Cause of Classification Noise Source Equipment Interference Noise Small-sized electric Electric device with Electric discharge Flashing signal device, relay, equipments contacts (spark, arc) electromagnetic conductor, (general/home thermostat electrical appliances) Equipment driven by Electric discharge Electric drill, vacuum cleaner commutator motor (spark, arc), sliding contact Electric discharge tube Glow discharge Neon discharge tube, high- pressure mercury arc lamp Control unit having Phase control Thyristor dimmer, inverter semiconductor devices (transient) noise High-frequency Industrial high- Disturbance signal* Industrial high-frequency facilities frequency equipment heater, high-frequency electric welder, etching equipment Medical high-frequency Disturbance signal* VHF/UHF treatment equipment apparatus Ultrasonic-wave Disturbance signal* Flaw detector, ultrasonic equipment cleaner Electric power Power cable (power High voltage, large Induction of commercial facilities transmission line) current power frequency (electrostatic induction, electromagnetic induction, current leak to ground) Electric discharge Corona noise, poor insulator, (corona, arc) poor contact due to corroded metal (arc discharge) Electric railway Electric discharge Pantagraph, internal (spark, arc) equipment in car, rectifier Reflection From car body Cassette transfer Magnetic field Cassette transfer equipment Internal combustion Automobile Electric discharge Ignition circuit engines Others Dynamo, voltage regulator Wireless Large-power Signal radiation* Broadcasting equipment, communication transmission radar facilities equipment Disturbance radiation High-frequency transmitterNote: The signal marked with "*" is required in the relevant system, but becomes a disturnance signal for other system. 1-7
  • 22. 1.1 Installation Requirements Power line (100 V AC, 50 A) Evacuation duct Vacuum, air, N2 source 225 360 140 Inside diameter of duct: 104 Inside diameter of duct: 54 640 420 Power (H=520) 600 30 kg supply unit (H=1500) 200 kg RP (Option) Maintenance (1000) 535 service area 259 168 200 150 345 180 296 (450) f 65 caster 150 91 (2 positions) 150 58 Clean room 125 122 150 f 60 stopper (4 positions) 80 310 570 Main column 708 Main unit base Control unit (6 positions) 1890 unit (H=1650) 974 (H=1800) 1331 1100 kg 320 kg f 60 stopper 130 (3 positions) 315 235 150 624 540 400f110 caster f 110 caster 287(2 positions) 50 500 (4 positions) 74 144 700 600 582 295 (Maintenance space for 134 main section) 719 512 309 260 1170 Dimensional unit: mm Fig. 1-1 Installation Layout 1Relevant instruments: (1) S-8840/S-8820 (2) S-8640 (3) S-8620’s with serial nos. 8343-xx onward 1-8
  • 23. 1.1.10 Power line (100 V AC, 50 A) Evacuation duct Vacuum, air, N2 source 225 360 Inside diameter of duct: 104 140 Inside diameter of duct: 54 640 420 Power (H=520) supply unit 600 30 kg (H=1500) 200 kg RP (Option) Maintenance (1000) 535 service area 200 345 150 450 180 296 f 65 caster 150 150 (2 positions) 58 Clean room 125 122 150 f 60 stopper 570 (4 positions) 80 310 Main unit base Main column (6 positions) Control unit 1810 unit (H=1650) 708 1331 974 (H=1800) 1100 kg 320 kg f 60 stopper 130 (3 positions) 235 315 150 624 540 400 f 110 caster f 110 caster 287 50 500 (4 positions) (2 positions) 144 74 700 600 582 295 (Maintenance space for 134 main section) 719 512 309 260 1170 Dimensional unit: mm Fig. 1-2 Installation Layout 2Relevant instrumente : (1) S-8620’s with serial no. 86xx-xx (2) S-8620’s with serial nos. up to 8342-xx 1-9
  • 24. 1.1 Installation Requirements1.1.11 Power CapacitanceThe power capacitance values of this instrument are shown below.(1) At continuous turn-on time (only the evacuation system is active during nighttime or stop of operation) • • • • • • • • • • • • • • • • • • • • • • •25 A(2) At operation of instrument (the evacuation system, stage and control circuit are active) • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 30 A(3) At maintenance of instrument (the electron gun is baked or subjected to heating/degassing treatment) • • • • • • • • • • • • • • • • • • • • • • • • • • • 45 A(4) Power capacitance reserved for accessory device • • • • • • • • • • • • • • • • • • • •10 A(5) Maximum power capacitance ••••••••••••••••••••••••••••••••••••••• 45 A* Under condition (3), it is not allowed to use electric power for stage, control circuit and accessory device.1.1.12 Evacuation Duct for Oil Rotary Pump (option) WARNING · Do not touch the metallic terminal section of the power supply cable for the oil rotary pump, or you may receive an electric shock. · 100 V AC is supplied to the oil rotary pump. If you touch the metallic terminal section of the power cable, it could result in death or serious injury. · Do not touch the oil rotary pump itself nor its cover while the pump is operating; there is a danger you will be burned. · The oil rotary pump becomes hot while it is operating. There is a danger of burns if you touch it. 1 - 10
  • 25. 1.1.12As shown below, install the evacuation duct for rotary pump within the maintenance service area. Evacuation duct Inside diameter of duct: 104 mm Inside diameter of duct: 54 mm 250 222 A B RP-2 RP-1 160 520 340 To column unit 640 360 Fig. 1-3 Evacuation Duct Piping for Oil Rotary Pump (option) 1 - 11
  • 26. 1.2 Items to Be Prepared by User1.2 Items to Be Prepared by User Item Quantity Remarks ¡ Hexane (C6H14) 1 bottle Used for cleaning parts, special grade (500 mL) ¡ Vacuum pipes (tube diameter 6 mm, 1 set For evacuation of cassette-to-cassette loader vacuum pressure P = 13 to 40 kPa) ¡ N2 gas and air tubes 1 set For loader chamber leak and valve drive N2 gas (tube diameter 6 mm, pressure 200 to 880 kPa) Compressed air (tube diameter 6 mm, pressure 600 to 880 kPa) ¡ Chamois leather cloth 1 set Used for cleaning devices and parts ¡ 3 Evacuation duct (More than 6 m /min 1 set For two oil rotary pumps per pump) ¡ Chair 1 set For operator ¡ Lift (More than 1500 N (150 kgf) 1 set For maintenance of main unit loadable at end) WARNING · Inhalation of N2 gas could be dangerous. · If tubing is performed with the N2 gas flowing, and a large amount of the gas is inhaled, it could cause breathing difficulty, and in the worst case, could be fatal. · Before carrying out tubing for the N2 gas, make sure to close the main valve for the N2 gas.Air, N2 and vacuum tube connectors: KQS06-02S made by SMCJunflon or equivalent tubes should be used for the air, N2 and vacuum tubing, and the tuberesistance should be sufficient to withstand the pressure of the customers facilities.When using tube joints (swage lock, VCR, etc.) other than specified by Hitachi, customer shouldprepave suitable tubing. (Connector size is Rc 1/4.) Tube outer dia. 6 mm Rc 1/4 1 - 12
  • 27. 1.31.3 Power and Ground Wiring ConnectionsThis instrument is designed to operate on 100 V input power voltage. WARNING · Do not touch the metallic terminal part of the power cable to the instrument. There is a danger of electric shock. · 100 V AC is supplied through the metallic terminal part of the power cable. Touching this part could result in fatal or serious injury due to electric shock. · Before connecting the instrument power cable or grounding wire to the power distribution board of the facility, make sure the output of the distribution board is turned OFF.If other than 100 V input power must be used at installation, it is required to use the autotransformer (available optionally). WARNING · Do not touch the input or output metallic terminal section of the transformer. There is a danger of electric shock. · 200 to 240 V AC is supplied through the input metallic terminal section and 90 to 115 V AC through the output metallic terminal section of the transformer. Touching these sections could result in fatal or serious injury due to electric shock. · Before connecting the power cable or grounding wire of the facility to the transformer, make sure the power distribution board output of the facility is turned OFF. 1 - 13
  • 28. 1.3 Power and Ground Wiring Connections[Reference]The tap voltage of the optional isolation transformer or auto transformer is shown in Fig. 1-4. 240 V INPUT 220 V 200 V 115 V 110 V 105 V 100 V OUTPUT 95 V 90 V Fig. 1-4 Voltage Terminal of Auto Transformer (option)Figure 1-5 shows the power cable connection from the distribution panel. The ground wireshould be grounded to a proper terminal (never connect the ground wire to a water pipe or thelike). (proper terminal is one with grounding resistance of less than 100 ohms) E3 E 2 100 V AC 100 V AC 1 Power supply unit Power distribution panel (1) When auto transformer is not used E3 E E 2 G 100 V AC Power input 1 other than 100 V AC Power supply unit Power distribution panel (2) When auto transformer is used Fig. 1-5 Connection of Auto Transformer 1 - 14
  • 29. 1.3Fig. 1-6 Wiring Diagram (S-8840/S-8640/S-8820/S-8620) 1 - 15
  • 30. 1.3Fig. 1-7 Wiring Diagram (S-8840/S-8640,MFG No. 9101-01 onward) 1 - 16
  • 31. 2.1 2. FUNCTIONS2.1 Appearance of Instrument SystemFigure 2-1 shows the appearance of Model S-8000 series system. Display unit Main column unit Fig. 2-1 Appearance of S-8000 Series (Power supply unit and oil rotary pump unit are not shown here.) 2-1
  • 32. 2.2 Specifications2.2 Specifications2.2.1 Specifications of S-8840/S-8640(1) General Wafer size : S-8840 • • • • 8-inch or 6-inch S-8640 • • • • 6-inch or 5-inch Principle of CD measurement : Cursor and line profile measurement CD measurement range : 0.1 to 10 µm CD measurement reproducibility : ±1% or 0.005 µm (3 sigma) (threshold method), whichever larger Throughput : 26 wafers/hour (in continuous measurement), 1 point/chip, 5 chips/wafer Secondary electron image resolution : 5 nm (50 Å) (at accelerating voltage of 0.8 kV) (with reference specimen dedicated for resolution measurement) Magnification : ´1000 to ´150,000 (SEM image) About ´110 (optical microscope image)(2) Specimen Stage Movement range : X and Y • • • • 0 to 200 mm Stage drive : Pulse motor Control and speed : Computer-controlled, max. speed 50 mm/s(3) Wafer Loader Wafer transfer from cassette to loader chamber : Auto transfer via cassette-to-cassette auto loader Wafer transfer from loader chamber to stage : Auto evacuation and auto loading(4) Cassette-to-Cassette Auto Loader Principle of loading : Loading via arm type robot for random access using two cassettes Chucking : Vacuum chucking on back of wafer Orientation flat setting : Non-contact auto detection via optical sensor 2-2
  • 33. 2.2.1(5) Electron Optics Electron gun : Schottky emission type (having high brightness and long service life) Accelerating voltage : 500 to 1300 V (variable in 10 V steps) Lens system : Electromagnetic condenser lens system, FCM objective lens Secondary electron detection : 2-stage detection system Objective lens aperture : Heating type movable aperture (4 openings selectable outside column), fine adjustment possible Scanning coil : 2-stage deflection Stigmator coil : 8-pole electromagnetic type (X, Y) Probe current monitoring : Faraday cup incorporated, with automatic measurement function Optical microscope : 1.2-mm-square visual field, monochrome image(6) Control and Display System Viewing control CRT : EWS (GUI) 20-inch monitor, integral processing image display, interactive computer operation, wafer map display, measured value indication, stage coordinate indication, etc. Scanning modes : TV scan, raster rotation, auto brightness/contrast control Photographing : Photographic recording unit, effective visual field 80 5 80 mm (option) Safety device : Equipped with emergency cut-off switch(7) CD Measurement Data Processing System (1 GB hard disk for system program *) File storage : 3.5-inch floppy disk drive, 3.5-inch magneto-optic disk drive, with storage function for various parameter files Data processing : Average value, standard deviation, maximum/minimum values Printout : 80-character thermal printer * Hard disk capacity varies with instrument serial no.(8) Vacuum System Principle of evacuation : Full automatic dry-clean evacuation Vacuum pumping : Ion pump (3 units), turbo molecular pump (2 units), rotary pump (option)(with foreline trap) (2 units) Safety device : Equipped with power fail/vacuum level safety devices(9) Dimensions Main column unit : 1170W 5 1890D 5 1650H mm, 1100 kg Display unit : 600W 5 1331D 5 1800H mm, 320 kg Power supply unit : 535W 5 600D 5 1500H mm, 200 kg Rotary pump (option) : 360W 5 640D 5 520H mm, 30 kg/unit 2-3
  • 34. 2.2 Specifications(10) Standard System Composition Main column unit • • • • • • • • • • • • • • • • • • • • • 1 Display unit • • • • • • • • • • • • • • • • • • • • • • • • • 1 Power supply unit • • • • • • • • • • • • • • • • • • • • •1 Photographing unit (option) • • • • • • • • • • • • • •1 Rotary pump (option) • • • • • • • • • • • • • • • • • • 2 Standard tools • • • • • • • • • • • • • • • • • • • • • • •1 set Spares and consumables • • • • • • • • • • • • • • •1 set Instruction manual • • • • • • • • • • • • • • • • • • • •12.2.2 Specifications of S-8820/S-8620(1) General Wafer size : S-8820 • • • 8-inch or 6-inch S-8620 • • • 6-inch or 5-inch Principle of CD measurement : Cursor and line profile measurement CD measurement range : 0.1 to 10 µm CD measurement reproducibility : ±1% or 0.005 µm (3 sigma) (threshold method), whichever larger Throughput : 20 wafers/hour (in continuous measurement), 1 point/chip, 5 chips/wafer Secondary electron image resolution : 5 nm (50 Å) (at accelerating voltage of 0.8 kV) (with reference specimen dedicated for resolution measurement) Magnification : ´1000 to ´150,000 (SEM image) About ´110 (optical microscope image)(2) Specimen Stage Movement range : X and Y ; 0 to 200 mm* Stage drive : Pulse motor Control and speed : Computer-controlled operation, max. speed 50 mm/s * Hard disk capacity varies with instrument serial no.(3) Wafer Loader Wafer transfer from cassette to loader chamber : Auto transfer via cassette-to-cassette auto loader Wafer transfer from loader chamber to stage : Auto evacuation and auto loading 2-4
  • 35. 2.2.2(4) Cassette-to-Cassette Auto Loader Principle of loading : Loading via arm type robot for random access using two cassettes Chucking : Vacuum chucking on back of wafer Orientation flat setting : Non-contact auto detection via optical sensor(5) Electron Optics Electron gun : Schottky emission type (having high brightness and long service life) Accelerating voltage : 700 to 1300 V (variable in 10 V steps) Lens system : Electromagnetic condenser lens system, FCM objective lens Secondary electron detection : 1-stage detection system Objective lens aperture : Heating type movable aperture (4 openings selectable outside column), fine adjustment possible Scanning coil : 2-stage deflection Stigmator coil : 8-pole electromagnetic type (X, Y) Probe current monitoring : Faraday cup incorporated, with automatic measurement function Optical microscope : 1.2-mm-square visual field, monochrome image(6) Control and Display System Viewing control CRT : EWS (GUI) 20-inch monitor, integral processing image display, interactive computer operation, wafer map display, measured value indication, stage coordinate indication, etc. Scanning modes : TV scan, raster rotation, auto brightness/contrast control Photographing : Photographic recording unit, effective visual field 80 5 80 mm (option) Safety device : Equipped with emergency shut-off switch(7) CD Measurement Data Processing System (1 GB hard disk for system program *) File storage : 3.5 inch floppy disk drive, 3.5 inch magneto-optic disk drive, with storage function for various parameter files Data processing : Average value, standard deviation, maximum/minimum values Printout : 80-character thermal printer * Hard disk capacity varies with instrument serial no.(8) Vacuum System Principle of evacuation : Full-automatic dry and clean evacuation Vacuum pumping : Ion pump (3 units), turbo molecular pump (2 units), rotary pump (option)(with foreline trap) (2 units) Safety device : Equipped with power fail/vacuum level safety devices 2-5
  • 36. 2.3 Main Column Units(9) Dimensions Main column unit : 1170W 5 1890D 5 1650H mm, 1100 kg (S-8620 with serial nos. 8343-xx onward and S-8820) 1170W 5 1810D 5 1650H mm, 1000 kg (S-8620 with serial no. 86xx-xx and nos. up to 8342-xx) Display unit : 600W 5 1331D 5 1800H mm, 320 kg Power supply unit : 535W 5 600D 5 1500H mm, 200 kg Rotary pump(option) : 360W 5 640D 5 520H mm, 30 kg/unit(10) Standard System Composition Main column unit • • • • • • • • • • • • • • • • • • • • • 1 Display unit • • • • • • • • • • • • • • • • • • • • • • • • • 1 Power supply unit• • • • • • • • • • • • • • • • • • • • • 1 Photographing unit (option)• • • • • • • • • • • • • •1 Rotary pump (option) • • • • • • • • • • • • • • • • • • 2 Standard tools • • • • • • • • • • • • • • • • • • • • • • • 1 set Spares and consumables • • • • • • • • • • • • • • • 1 set Instruction manual • • • • • • • • • • • • • • • • • • • • 1 2-6
  • 37. 2.3.12.3 Main Column Units WARNING · Do not touch components inside the instrument. There is a danger of electric shock. · There are circuits using 6 kV DC and 100 V AC inside this unit. Touching live or exposed parts of the circuits could result fatal or serious injury due to electric shock. · Before detaching the cover of this unit, be sure to carry out the workstation shutdown sequence and turn OFF the power of the electron gun HV power supply.2.3.1 GeneralFigure 2-2 shows the appearance of the main column unit of S-8000 series. The microscopecolumn (including the electron gun, lens system and secondary electron detector) is enclosed byexternal covers.Stage/evacuation control (manual) panel Column front cover Objective movable aperture Specimen chamber(inside) Auto loader Vacuum system (inside) Load lock chamber Fig. 2-2 Appearance of S-8000 Series Main Column Unit 2-7
  • 38. 2.3 Main Column Units2.3.2 Evacuation SystemFigure 2-3 shows the evacuation system arrangement for S-8840, S-8640, S-8820 and S-8620. IP1 MV1 N2 IP2 MV2 LV2 F IP3 LV1 MV3 Pi3 LD AV1 XC VS LC AV2 SC Pe2 AV3 Pi2 Pe1 AV5 Pi1 AV8 AV6 AV4 TMP1 LV3 AV7 LV4 TMP2 RP1 RP2 IP1, 2, 3 : Ion pumps RP1, 2 : Rotary pumps TMP1, 2 : Turbo molecular pumps Pi1, 2 : Pirani gauges Pe1, 2 : Penning gauges VS : Atmospheric pressure sensor LV1 ~ LV4 : Leak valves AV1 ~ AV8 : Vacuum valves F : Filter AV1 : Electron gun-specimen chamber airlock valve AV2 : Specimen chamber-loader chamber airlock valve Fig. 2-3 Evacuation System Arrangement (S-8840, S-8640, S-8820, S-8620) 2-8
  • 39. 2.3.32.3.3 Evacuation Control (Manual) Panel(1) VALVE CONTROL Section CAUTION The VALVE CONTROL section is provided with switches exclusively for use by the service engineers. The user should never tamper with these switches, or else a serious trouble might occur in the system. AUTO-MANUAL switch : Used for selection between the full AUTO mode and MANUAL mode of evacuation system operation. (For exclusive use by service personnel) VALVE AV1 to AV8, LV1 to 2 switches : Used for opening/closing each valve manually. (To open each valve, turn the switch to UP position; to close it, turn the switch to DOWN position.) The middle-point dot (•) indicates the stop state. (For exclusive use by service personnel) The lamp located above each switch lights up when the valve is opened.(2) ION PUMP Section RANGE (Pa) switch : Used for selecting a vacuum level range of the ion pump. Pa = Pascal -3 1 Pa = 7.5 5 10 Torr 1 Torr = 133 Pa ION PUMP meter : Indicates a vacuum level of the ion pump (IP). RESET switch : Used to reset and start the ion pump (IP1, IP2, IP3). SELECT switch : Used for selecting a reading of the vacuum gauge (meter) of ion pump.(3) PIRANI & PENNING GAUGE Section PIRANI & PENNING GAUGE meter : Indicates a reading of the Pirani/Penning vacuum gauge. SELECT switch : Used for meter reading selection. 2-9
  • 40. 2.3 Main Column Units(4) TMP CONTROL Section START switch : Used to start up the TMP motor. Pressing this switch turns on the pump. STOP switch : Used to stop the TMP motor. FAIL lamp : Lights up if the TMP operation becomes abnormal. ACC lamp : Lights up during an acceleration period until the TMP motor reaches its normal rotating speed after the START switch is pressed. NORM lamp : Lights up when the TMP reaches its normal rotating speed (rated speed level).(5) ION PUMP BACKUP Section (Available in case the optional ion pump backup power supply is equipped) BATTERY OPERATION switch : During operation of this instrument, keep this switch to ON position always. When the main power supply and this switch are turned off, the output voltage for pump goes off. AC ON lamp : Indicates that the main (AC) power is connected. HV ON lamp : Indicates that the output voltage for pump is turned on. When this lamp remains lit even after the main (AC) power is shut off, it indicates that a high voltage is applied to the pump. Before removing the ion pump voltage connector or air- leaking the electron gun chamber, turn off the BATTERY OPERATION switch and make sure that this lamp is extinguished. Meter : Indicates an item chosen by the SELECT switch mentioned below. SELECT switch : Used for meter reading selection. 5100 mA 510 mA : Indicates an output current of the pump power supply. (When the main power supply is turned on, the reading is zero.) kV : Indicates an output voltage of the pump power supply. 4.5 kV is applied under normal condition. V/BATTERY : Indicates a battery voltage. When a voltage of less than 12 V is indicated, the charged amount of battery voltage is insufficient. 2 - 10
  • 41. 2.3.3 V/CHARGE : When this switch position is selected, a battery voltage is indicated on the meter and the quick charging operation is performed. If the charged amount of battery voltage is insufficient (less than 12 V on V/BATTERY range) or the backup function is activated due to power failure, turn the SELECT switch to any other position once and then return it to this position. (Quick charging is performed for approx. 10 hours. After completion of quick charging, the normal charge condition is set up.) APS lamp : Turns on when the valve drive air pressure is higher than the specified level. VS lamp : Turns on when the specimen exchange chamber has atmospheric pressure. APT HEAT lamp : Turns on when the objective aperture is heated.(6) Stage/Loader Control (Manual) Section CAUTION This control panel is intended exclusively for use by the service engineers. The user should not tamper with this panel. AUTO-MANUAL switch : Used for selection between the CPU-controlled automatic operation of stage/loader and the manual operation. (For exclusive use by service personnel) SPEED select switch : Selects a stage travel speed; HIGH, MED (IUM), or SLOW. X(+), X(-) switch : Selects the positive (+) or negative (-) direction of X movement of the specimen stage. Y(+), Y(-) switch : Selects the positive (+) or negative (-) direction of Y movement of the specimen stage. L(+) switch : Transfers the wafer holder from the load lock chamber to the specimen stage. (Functional only in the MANUAL mode) L(-) switch : Transfers the wafer holder from the specimen stage to the loader chamber. (Functional only in the MANUAL mode) CHUCK switch : Used to chuck the wafer holder when unloading it. (Functional only in the MANUAL mode) UNCHUCK switch : Used to unchuck the wafer holder when loading it. (Functional only in the MANUAL mode) ARM switch : Used for wafer exchange in the load lock chamber between the wafer holder and the station. 2 - 11
  • 42. 2.3 Main Column Units PALETTE switch : Moves up/down the center palette at the station. STAGE CONTROL X Y : Indicates X-Y coordinates of the specimen stage. (Unit: µm) X LIMIT (+) (-) lamp : Lights up if the positive (+) or negative (-) direction limit of X stage movement is exceeded. This lamp does not turn on under normal operation. (Flashing of this lamp indicates an overrun state.) Y LIMIT (+) (-) lamp : Lights up if the positive (+) or negative (-) direction limit of Y stage movement is exceeded. This lamp does not turn on under normal operation. (Flashing of this lamp indicates an overrun state.) LOADER LIMIT (+) lamp : Lights up if the loader moves beyond the topmost position on stage side. This lamp does not turn on under normal operation. (Flashing of this lamp indicates an overrun state.) LOADER LIMIT (-) lamp : Lights up if the loader moves beyond the return position in the load lock chamber. This lamp does not turn on under normal operation. (Flashing of this lamp indicates an overrun state.) CHUCK lamp : Indicates that the loader is ready to chuck the wafer holder. HOLDER ON STAGE lamp : Indicates that the wafer holder is placed on the stage of specimen chamber. HOLDER ON LOADER lamp : Indicates that the wafer holder is set at the home position of load lock chamber. WAFER ON STATION lamp : Indicates that the wafer is set on the station in the load lock chamber. WAFER ON HOLDER lamp : Indicates that the wafer is set on the wafer holder in the load lock chamber. LOAD/UNLOAD POSITION lamp : Indicates that the stage is located at the LOAD/UNLOAD position. WAFER STATION UP lamp : Indicates that the wafer station is in the specimen exchange chamber. WAFER STATION DOWN lamp : Indicates that the wafer station is in the load lock chamber. 2 - 12
  • 43. 2.3.3TRANSFER ARMCHUCK A lamp : Indicates that a voltage is applied to the vacuum-chuck arm A.TRANSFER ARMCHUCK B lamp : Indicates that a voltage is applied to the vacuum-chuck arm B. 2 - 13
  • 44. 2.3.3 ION PUMP 10-4 10-5 10-6 STAGE CONTROL X LIMIT + 10-3 10-7X X LIMIT - RANGE Y LIMIT + APS IP2 IP1 IP3 Y LIMIT - VSY LOADER LIMIT + SELECT APT HEAT IP1 IP2 IP3 LOADER LIMIT - PIRANI & PENNING GAUGE Pi3 Pi2 Pe1 LOAD/UNLOAD POSITON CHUCK Pi1 Pe2 WAFER STATION UP HOLDER ON STAGE SELECT WAFER STATION DOWN HOLDER ON LOADER kV ON ION PUMP x10µA V/BATTERY BACK UP TRANSFER ARM CHUCK A WAFER ON STATION x100µA V/CHARGE OFF TRANSFER ARM CHUCK B WAFER ON HOLDER BATTERY SELECT OPERATION MANUAL SPEED X+ Y+ L+ CHUCK ARM PALETTE AC ON HV ON AV1 AV2 AV3 AV4 AV5 AV6 AV7 VALVE CONTROL AUTO X- Y- L- UNCHUCK OPEN MANUAL CLOSE START NORM FAIL START NORM FAIL AV8 AV9 AV10 AV11 LD LV1 LV2 AUTO START STOP START STOP OPEN TMP 1 TMP 2 CLOSE Stage/loader control (manual) section Evacuation control (Manual) section Fig. 2-4 Stage/Evacuation Control (Manual) Panel (S-8840/S-8640/S-8820/S-8620) 2 - 14
  • 45. 2.3.42.3.4 Auto Loader System(1) Outline of Auto Loader This auto loader is of a cassette-to-cassette type which loads/unloads wafers automatically. Up to two wafer cassettes can be set on the auto loader. Wafer cassette Auto loader Load lock chamber Fig. 2-5 Auto Loader on S-8000 Series(2) Major Specifications of Auto Loader Wafer size : On Model S-8840/S-8820 • • • •8 or 6 inches in diameter (conforming to the SEMI and JEIDA standards) On Model S-8640/S-8620 • • • •6 or 5 inches in diameter (conforming to the SEMI or JEIDA standards) Principle : Random access loading with two cassettes Chucking : Vacuum-chucking on back side of wafer Orientation flat setting : Automatic setting 2 - 15
  • 46. 2.3 Main Column Units(3) Functions of Auto Loader Orientation flat sensor Wafer transfer arm Cassette positioning guide Wafer transfer (WT) Cassette positioning guideCassette mounting base Cassette mounting base Side-A cassette operation Side-B cassette operation indicator lamp indicator lamp Fig. 2-6-1 Mechanisms of Auto Loader Cassette mounting base : Mounts the wafer cassette. Cassette positioning guide : Used for positioning the wafer cassette for correct mounting. Side-A cassette operation indicator lamp : This lamp indicates the cassette operation state on side A as described below. (One of the following lamps lights up or flashes.) MOUNTED : Lights up when the wafer cassette is set. WAITING : Lights up when the auto loader is waiting for processing (after the instruction for processing is given). PROCESSING : Flashes during wafer processing. FINISHED : Lights up on completion of wafer processing. Turns off when the cassette is removed. Side-A cassette means the wafer cassette located near the loader chamber. 2 - 16
  • 47. 2.3.4Side-B cassette operationindicator lamp : Functionally same as the side-A cassette operation indicator lamp. Side-B cassette means the wafer cassette located farther from the loader chamber.Orientation flat sensor : Detects the orientation flat and centering position of wafer. The position of sensor varies depending on the wafer size.Wafer transfer arm : Transfers the wafer into or out of the specimen exchange chamber. a) At Loading The wafer is taken out of the side-A/B wafer cassette. ¯ The wafer is transferred to the orientation flat sensor and then transferred out of it. ¯ The wafer is transferred to the station holder in the specimen exchange chamber. b) At Unloading The wafer is transferred out of the station holder in the specimen exchange chamber ¯ The wafer is stored into the side-A/B wafer cassette. 2 - 17
  • 48. 2.3 Main Column Units(4) Mounting of Wafer Cassette CAUTION Beware of injury · There is a possibility of injury while the wafer transfer mechanism is operating. · Do not touch inside the cassette loader with the power turned on. Place the wafer cassette onto the cassette mounting base. At this step, make sure that the cassette positioning plates are secured positively on the cassette mounting base. If the wafer cassette is not mounted properly, pressing the START switch causes an error message to appear on the CRT monitor to indicate the inoperable condition. Cassette Cassette positioning plate Cassette mounting base Fig. 2-6-2 Mounting of Wafer Cassette 2 - 18
  • 49. 2.3.52.3.5 Objective Movable Aperture Control APERTURE SELECT knob FINE ADJUST (X) knob FINE ADJUST (Y) knob Fig. 2-7 Objective Movable Aperture ControlAPERTURE SELECT knob : Used for selecting one of four apertures. (Diameter of opening: 0.002 mm ´ 4)FINE ADJUST (X) knob : Used for fine adjustment in the X-axial direction (perpendicular to IN/OUT direction).FINE ADJUST (Y) knob : Used for fine adjustment in the Y-axial direction (IN/OUT direction). 2 - 19
  • 50. 2.4 Display Unit2.4 Display Unit2.4.1 Appearance of Display UnitFigure 2-8 shows the appearance of the display unit. Electron gun high voltage power supply Power supply switch panel Display monitor (Workstation main unit) Floppy disk drive Keyboard, mouse Operation table/panel Printer Magneto-optical disk drive Fig. 2-8 Appearance of Display Unit2.4.2 Functions(1) Power Supply Switch Panel Figure 2-9 shows the layout of the power supply switch panel. STAGE switch EVAC switch SEM switch IP/HV switch SEM STAGE EVACE I.P/HV EMERGENCY STOP ON ON ON ON EMERGENCY STOP switch OFF OFF OFF OFF Fig. 2-9 Layout of Power Supply Switch Panel 2 - 20
  • 51. 2.4.2EMERGENCY STOPswitch : Pressing this switch shuts off all the power supply circuits other than that of the workstation main unit. < In case the backup power supply is mounted > Even after this switch is pressed, the electron gun evacuation ion pump and the electron gun high voltage power supply remain active for a specified period of time. Take the following procedure for stopping the buzzer. 1) Make sure there is no problem related to safety. 2) Remove the rear cover from the power supply rack. 3) Turn OFF the power switch of the backup power supply for workstation, located on the 2nd shelf from the top in the power supply rack. Before using the instrument, turn ON the power switch of the backup power supply for workstation, and then start up the instrument.IP/HV switch : Serves as the main power switch for the ion pump power supply and the electron gun high voltage power supply.EVAC switch : Turns on/off power to the evacuation system.STAGE switch : Turns on/off power to the stage/loader system.SEM switch : Turns on/off power to the display unit.Four switchesdescribed above• • • Power is connected by pressing ON, and it is disconnected by pressing OFF. Under normal condition, power to the display unit should be turned on/off through the workstation. Use the above SEM switch to shut off power only when abnormality (e.g. disabled workstation operation) takes place. For power supply to the ion pump, it is also required to make setting on the evacuation control panel. Pressing the EMERGENCY STOP switch cuts off the power supply. But for the workstation, power is cut off after completing the shutdown process via the backup power supply. If the IP/HV ON lamp does not light up even when the switch is pressed or goes off when it is released, check whether the main switch on power supply rack or the relevant circuit breaker is turned on or not. 2 - 21
  • 52. 2.4 Display Unit(2) Electron Gun High Voltage Power Supply Figure 2-10 shows the layout of the electron gun high voltage power supply panel. Do not touch this panel unless it is necessary to shut off the electron gun high voltage power due to abnormality. HV READY lamp HV ON lamp Display select switch ho urs Display window Heating current setting Display select lamp M A X If dial If D OW N UP ST ART U P Vs V1 Power supply indicator PO W ER Ie If GND ST ART D OW N V2 Control switch lamp V0 POWER switch Fig. 2-10 Layout of Electron Gun High Voltage Power Supply Under normal condition, set the POWER switch to ON position always. The high voltage power to electron gun should be turned on/off through the workstation. Turn off the POWER switch only when operation through the workstation is disabled and the high voltage power must be shut off. NOTICE: This is because the probe current will become unstable. Each press of the display select switch presents each data in succession on the display window. The display select lamp indicates what item is being displayed. The following items can presented on the display window. If : Heating current to Schottky emitter Vs : Suppressor voltage V1 : Emission extracting voltage V2 : Intermediate electrode voltage V0 : Accelerating voltage (When a retarding voltage is applied, this accelerating voltage level differs from that indicated in image operation.) Ie : Emission current Under normal condition, select Ie (emission current) for display. 2 - 22
  • 53. 2.4.2(3) Display Monitor The display monitor is equipped for workstation operation. It can present all the information necessary for operation (including images).(4) Keyboard and Mouse For ordinary operation, the screens on the display monitor can be controlled using the mouse. To enter numeric values and file names, use the keyboard. For details of the operational procedures, refer to OPERATION SECTION of Instruction Manual.(5) Control Panel Use the control panel for image focus adjustment or other control operations that are rather difficult to perform with the mouse. Fig. 2-11 shows the layout of the control panel. STIGMA knob FOCUS knob STIGMA FOCUS OFF switch B EA M S T AG E OF F STAGE switch BEAM switch Trackball Fig. 2-11 Layout of Control Panel FOCUS knob : Used for manual focus adjustment of SEM image. STIGMA knob : Used for manual astigmatism correction of SEM image. BEAM switch : When this switch is pressed, its lamp (located above) lights up. In this state, the visual field of image (electron beam) can be shifted using the trackball. The visual field shift range is limited to 30 µm. STAGE switch : When this switch is pressed, its lamp (located above) lights up. In this state, the specimen stage can be moved using the trackball. OFF switch : Pressing this switch turns off both the BEAM and STAGE lamps. In this state, the trackball is not effective. The above functions are also available through use of the workstation. 2 - 23
  • 54. 2.4 Display Unit(6) Printer This printer is used for measurement data output. Fig. 2-12 shows the external view of the printer. Lever RESET switch FEED switch ERROR lamp Paper stocker cover PAPER END lamp ON lamp Fig. 2-12 External View of Printer FEED switch : Used for paper feed. RESET switch : If the ERROR lamp lights up, press this switch with the tip of mechanical pencil or the like. ON lamp : Indicates power connection to the printer. When this lamp is lit, power is supplied to the printer normally. PAPER END lamp : Lights up when paper runs out. ERROR lamp : Lights up if any error is encountered with the printer. Lever : To insert paper, turn this lever up. For printing, turn it down. 2 - 24
  • 55. 2.4.2 How to Load Printing Paper WARNING · Do not touch the paper cutter, or you may cut your fingers. The cutter has a sharp blade. · On occurrence of a paper jam, remove the jammed part of paper using tweezers, not your bare hands. Open the cover of paper stocker, turn the lever up, and take out the core shaft. Insert the core shaft into a new roll of paper, set it on the paper holder. Then, run the top of paper roll through the printing section as shown below. (It is advisable to fold the top of paper into a triangular form so that paper can be run through the printing section easily.) When the top of paper appears from the outlet, turn the lever down. Then, by pressing the FEED switch, make sure that paper is fed normally. Lever Paper cutter Printing section Paper inlet Stocker cover Structure of Printer How to Cut Printing Paper The cutter is provided along the top of the paper outlet. For cutting paper, pull it obliquely upward. How to Print Out For the data printout procedure, refer to OPERATION SECTION of Instruction Manual.(7) Magneto-optical Disk Drive The 3.5-inch magneto-optical disk drive is equipped in the display unit. For the operational procedure, refer to OPERATION SECTION of Instruction Manual. 2 - 25
  • 56. 2.5 Power Supply Unit2.5 Power Supply Unit WARNING · Do not touch components inside this unit, or you may receive an electric shock. · This unit supplies 5 kV DC and 100 V AC to the display unit and column unit. Touching live or exposed parts inside this unit may result in fatal or serious injury due to electric shock. · Before detaching the cover of this unit, be sure to turn OFF all the power to the instrument. 2 - 26
  • 57. 2.5.12.5.1 GeneralThe power supply unit is designed for supplying power to each circuit of this system. Fig. 2-13shows the external view of the power supply unit. ELECTRICITY ON lamp POWER ON lamp EMERGENCY STOP switch E L E C T R IC IT Y O N P OW E R O N E M E R GE N C Y S T O P < Ion pump power supply section > IP1 switch and lamp IP2 switch and lamp IP3 switch and lamp INNER BAKE switch OUTER BAKE switch OUTER BAKE circuit breaker < Baking timer > EVAC POWER circuit breaker RP1 circuit breaker IP/FL POWER circuit STAGE POWER circuit breaker DISPLAY POWER circuit breaker RP2 POWER circuit breaker MAIN circuit breaker PUSH switch Fig. 2-13 External View of Power Supply UnitELECTRICITY ON lamp : Lights up when commercial power is fed to the input circuit of the power supply unit.POWER ON lamp : Lights up when the MAIN circuit breaker of the power supply unit is turned on. 2 - 27
  • 58. 2.5 Power Supply UnitEMERGENCY STOPswitch : Used to shut off the entire power to the instrument system (except the workstation unit). Note: Where the backup power supply circuit for the electron gun evacuation pump/electron gun high voltage power supply is provided, power is supplied continuously for a predetermined period of time even if the EMERGENCY STOP switch is pressed. Take the following procedure for stopping the buzzer. 1) Make sure there is no problem related to safety. 2) Remove the rear cover from the power supply rack. 3) Turn OFF the power switch of the backup power supply for workstation, located on the 2nd shelf from the top in the power supply rack. Before using the instrument, turn ON the power switch of the backup power supply for workstation, and then start up the instrument.< Ion Pump Power Supply Section > IP1 switch and lamp IP2 switch and lamp IP3 switch and lamp : These power switches are equipped for three ion pumps. Each power lamp lights up when the relevant ion pump is powered on. Even if the power switch is turned on, the power lamp does not light up after the protective circuit is activated due to overload or other causes. In this case, it is required to press the ion pump reset switch located on the evacuation control panel (on the front of main column unit). The evacuation control panel is also provided with the ion pump power lamp. In ordinary operation, use it to check power-on condition of the ion pump. 2 - 28
  • 59. 2.5.1INNER BAKE switchOUTER BAKE switchOUTER BAKE circuit breakerBaking timer : These switches and timer are used for baking the electron gun (degassing operation by heating). The baking of electron gun should be conducted by service personnel. So, keep the above three switches at OFF positions. The user should not turn on these switches. On the timer, all the knobs should be set at the extreme counterclockwise positions. Even if these switches are turned on, heating is not carried out to ensure safety (unless the high voltage cable is removed from the electron gun and set in the specified cable compartment).EVAC POWERcircuit breaker : Serves as the main circuit breaker for the evacuation system.RP1 POWER circuit breakerRP2 POWER circuit breaker : Serves as the circuit breakers for the rotary pumps equipped behind the evacuation power supply. Equipped to protect the rotary pumps against overcurrent. Power is not supplied to the evacuation system unless both the circuit breakers are turned on.DISPLAY POWERcircuit breaker : Serves as the main circuit breaker for the display unit.STAGE POWERcircuit breaker : Serves as the main circuit breaker for the specimen stage unit.IP/FL POWER circuit breaker : Serves as the main circuit breaker for the ion pump power supply (for electron gun evacuation) and the electron gun high voltage power supply.MAIN circuit breakerPUSH switch : Used for turning on/off power to the entire power supply unit. The electric leakage breaker function is provided. For power connection, turn on the MAIN circuit breaker while holding down the PUSH switch. The MAIN circuit breaker shuts off in the following cases: (1) On occurrence of electric leakage (2) At power recovery after power failure (3) When the EMERGENCY STOP switch is pressed After one of the above events takes place, the MAIN breaker lever is set at the middle position. To turn power on again, press the lever to DOWN position once. Then, throw the lever to UP position while holding down the PUSH switch. 2 - 29
  • 60. 3.1 3. PRINCIPLE OF MICROSCOPE INSTRUMENT3.1 Schottky Emission (SE) Electron SourceThe Schottky emission electron source, proposed by Dr. N.W. Swanson, et al. in the 1980s, hasoutstandingly excellent stability in its emission current. Owing to this superb feature, it hasfound extensive applications in a variety of electron beam devices.Briefly described below is the principle of SE electron source.A single crystal of tungsten (100) is formed into a probe having a curvature radius of approx.0.5 µm. Then, its tip is heated at about 1800 K in vacuum. Simultaneously, a monolayer ofZr-O is diffused on the tip so that 100 facets are provided on it. This results in the workfunction of tip being decreased from 4.5 eV to 2.7 eV, thereby making it easy to extract electronsin vacuum. Thus, the intensity of electron emission can be increased even at a low extractingvoltage.The stability of electron beam emitted in the above method largely depends on the vacuum levelin the atmosphere in which the tip is located. It is therefore required to provide ultra-high -7vacuum (10 Pa) in the atmosphere. Also, to ensure the stability of electron beam, the tip mustbe heated at all times. If the high voltage power supply for electron gun goes off due to apower failure, a period of approx. 30 minutes must be allowed before turning on electronemission again (including the diffusion time of Zr-O and the time until the temperature of tip issaturated up to about 1800 K). 3-1
  • 61. 3.2 Electron Optical System3.2 Electron Optical System3.2.1 Retarding MethodIn this instrument, the retarding method is adopted to enhance resolution in a low acceleratingvoltage range.In the retarding method, a negative potential is applied to a wafer (specimen) for deceleratingelectron beam between the objective lens and the specimen. Fig. 3-1 shows the schematicdiagram of the retarding method. Until passing through the objective lens, the electron beam isaccelerated up to Vo. After going through the objective lens, the electron beam is deceleratedwith -VR applied to the specimen. Thus, the decelerated electron beam falls on the specimen.The accelerating voltage of electron beam incident on specimen (Vacc) is expressed as Vo-VR.This retarding method can make resolution far better than conventional approaches.In the present design, the retarding method mentioned above is used in a low acceleratingvoltage range of 700 to 800 V. In a high accelerating voltage range of 810 to 1300 V, the FCM(field control method)* is used. Changeover between the retarding method and the field controlmethod is performed automatically.* The field control method has also been adopted in the conventional models. A positive potential is applied to the FCM electrode shown in Fig. 3-1. In this method, the potential of specimen is set at zero (0). 3-2
  • 62. 3.2.23.2.2 Note on Retarding Method OperationIn the retarding method, since an electric field is applied between the objective lens andspecimen, astigmatism increases in a wafer circumferential area of 10 mm. So, avoidobservation/CD-measurement in this area. If it is required to carry out observation/CD-measurement in this area, set the accelerating voltage to 810 V or higher for FCM operation. FCM electrode Electron beam accelerated to Vo Objective lens Specimen holder (wafer) Electron beam Retarding (decelerating) incident on specimen (Vacc) -VR electric field Vacc=VO-VR Fig. 3-1 Principle of Retarding MethodAlthough a negative potential is applied to a wafer in the retarding method as mentioned before,continuity is established through contact with the end face of wafer.If the surface or end of a wafer is covered with an insulating film, a potential cannot be appliednormally. And when the electron beam is irradiated, chargeup may occur to prevent normalimage observation. In such cases carry out the following for observation and CD measurement.(1) Remove the insulating film from the wafer end.(2) Set accelerating voltage to 810 V or higher and use the FCM mode for observation and measurement. 3-3
  • 63. 3.3 Two-Stage Detection System (S-8840/S-8640)3.3 Two-Stage Detection System (S-8840/S-8640)In this system, an additional detector is provided to improve the detection efficiency forsecondary electrons emitted from the specimen. The purpose is to alleviate specimen damagedue to contamination by reducing the probe current at observation and CD measurement.And by adding a second detector, secondary electrons that could not be detected by the ordinarysystem using a single detector are now detectable, and new information can be obtained uponforming secondary electron images.Figure 3-2 gives an outline of the secondary electron detection method in the two-stagedetection system. Since the energy of secondary electrons accelerated by the retarding voltageis high, they cannot be detected directly. So, in the single-stage detection system, thesecondary electrons from the specimen strike the conversion electrodes, then the secondaryelectrons emitted from the electrodes are detected by the first detector. But since there aresome small holes (up to 4 mm dia.) in the conversion electrodes to let the primary electrons passthrough, some of the secondary electrons from the specimen also go upward through theseholes, and the S-8820/S-8620 did not allow detecting these signals.In the two-stage detection system, another conversion electrode and a second detector areadded above the first electrode and detector, whereby secondary electrons that wereundetectable in the single-stage system are now detectable. This improves the detectionefficiency and allows reducing the probe current. Conversion electrode Second detector Mixer SEM image signal Conversion electrode First detector Resist film, etc. Wafer Substrate Fig. 3-2 Outline of Secondary Electron Detection in Two-Stage Detection System 3-4
  • 64. 4.1 4. COMPUTER SYSTEM AND SOFTWARE4.1 Computer System ConfigurationFigure 4-1 shows the computer system configuration of CD-measurement SEM. A total of eightCPUs are provided to inter-work with one another through communication. These CPUs areconfigured so that they are controllable from the engineering workstation (EWS). Also, the colorCRT monitor of EWS can display SEM images or optical microscopical images. Briefed beloware the functions of CPU.(1) EWS Offers an easy-to-use operating environment with the state-of-the-art GUI (graphical user interface) technology.(2) SEM Controller Designed to manage other control circuits in an integrated fashion. Also, this unit carries out sequence processing for operation of electron optical mechanism, loading/unloading of wafer, etc.(3) Image Processing Unit Used to search for an alignment mark or measurement pattern automatically. For automatic search, it is necessary to store alignment marks and measurement patterns in advance.(4) HV Control Unit Carries out control of the electron gun.(5) Evacuation Control Unit Carries out the evacuation/air-purge sequence for the specimen chamber and loader chamber.(6) Stage Control Unit Controls wafer movement in the specimen stage/vacuum chamber.(7) WT (Wafer Transport) Control Unit Controls wafer movement in atmosphere.(8) OFS Control Unit Used for detection of orientation flat. 4-1
  • 65. 4.1 Computer System Configuration Hard disk drive External computer Ethernet RS - 232C 3.5 inch MO drive EWS PA - RISC GUI Mini-printer Keyboard Mouse Color CRT 1280 ´ 1024 Image Processing unit Pattern recognition Operation control panel SEM controller HV Maintenance control unit service panel Evacuation Stage control unit WT control unit OFS control unit control unit Wafer transfer Maintenance Maintenance Maintenance service panel service panel service panel Fig. 4-1 Computer System Configuration 4-2
  • 66. 5.1 5. FILESIn this system, a set of data such as CD-measurement result data is referred to as a file.Data contained in each file can be processed collectively. The files are classified into two majorcategories as shown below.(1) System Files Controlled by the operating system of computer. The system files cannot be accessed directly by the user.(2) User Files Can be created or deleted by the user.5.1 System FilesTable 5-1 shows the kinds and contents of system files.The system files are stored on the hard disk and loaded automatically at power-on. These filesare run transparently, i.e. it is not required for the user to pay attention to them for operation. Table 5-1 System Files Name Description Related Window Automatic CD-measurement Stores parameter data for CD-measurement Image Operation parameter file CD-measurement value Stores offset value data of CD measurement error Image Operation correction file due to a change of magnification User name record file Contains the user name, password, etc. Login Stage coordinate storage file Used to hold up to 50 stage coordinate positions Stage Controller Stage coordinate instrumental Used to hold instrumental error data for stage Stage Controller error correction file coordinates on particular instrument Optical microscope-electron Stores visual field correction value data for the Stage Controller microscope visual field optical microscope and electron microscope correction file Stage coordinate calibration Stores calibration value data for stage file coordinates Instrument calibration file Stores instrument calibration data such as deflection point of electron beam, up/down step ratio of image shift, etc. 5-1
  • 67. 5.2 User Files5.2 User FilesTable 5-2 shows the kinds of contents of user files. Table 5-2 User Files Name Description Remarks IDW file Stores the on-wafer chip array and its size. Creation, revision, display (Wafer information file) • IDW Editor IDP file Stores the alignment pattern and CD- Creation, revision, display (CD-measurement pattern measurement pattern positions. • IDP Editor file) Recipe file Stores the RECIPE name, relevant IDW Revision, display and IDP file names, CD-measurement slot • Recipe Editor data, etc. CD-measurement data file Stores the result data of CD- Creation measurement. • Created automatically in execution of recipe. Display • Work Sheet Image file Stores images. Creation • Image Operation • Created automatically in execution of recipe Display • Image File Manager • Work Sheet 5-2
  • 68. 5.2.15.2.1 Hierarchical File StructureFigure 5-1 shows the hierarchical structure of user files. In this system, all the user files arecreated and saved hierarchically under each parent directory class. This hierarchical filestructure is convenient for the user to classify files according to the kind of product or the processof fabrication.Each IDP file is created under the directory of relevant IDW file because of its nature.So, before creating an IDP file, be sure to prepare an IDW file corresponding to it. Recipe Recipe IDP 1 IDP 1 IDW 1 IDW 1 IDP 2 IDP 2 class class 1 1 IDW 2 IDW 2 CD-measurement data 1 Image 1 Image 1 class class 2 2 Fig. 5-1 Hierarchical Structure of User Files 5-3
  • 69. 5.2 User Files5.2.2 Handling of User FilesDescribed below is the general handling procedure for user files.(1) IDW and IDP Files An IDW/IDP file can be created, modified, copied, deleted or renamed through use of each File Manager. For manual file loading, use the Manual Controller screen. When CD-measurement is carried out with recipe specified, the relevant IDW and IDP files are loaded automatically. A name of IDW/IDP file can be given within 40 characters, including alphanumeric characters, underbar (_) and hyphen (-).(2) Recipe File One recipe file is provided for each class directory. Each recipe file can contain up to 1000 recipe data. Using the Recipe Manager, you can create, modify, copy, delete or rename recipe data. Measurement using recipe data can be carried out through the Recipe Controller window. A recipe name may consist of up to 40 characters, including alphanumeric characters, underbar (_) and hyphen (-).(3) CD-measurement Data File A CD-measurement data file is automatically generated in execution of the recipe that instructs saving of CD-measurement file. It is named in the format shown below. "Date and time when CD-measurement is started _ Recipe name" Using the MSR File Manager, you can copy, delete or rename a CD-measurement data file. Also, on the MSR Eraser window (utility), you can specify automatic file deletion of CD- measurement data file. With setting of this function, the CD-measurement data file will be deleted automatically when the specified number of days is reached.(4) Image File (option) An image file can be created in the following two ways. (a) Storing from the Image Operation window Click the Image... button of Image Operation, and the SEM Image Register screen will open. Now enter a file name on this screen, and the image under observation will be saved. (b) Execution of recipe for which image save is specified Execute the recipe for which image save is specified, and the images at alignment, at detection of measurement pattern, and at CD measurement will be automatically saved. An image file can be displayed, copied, deleted, renamed or compressed through use of the Image File Manager. The images in the image file created automatically by the above method (b) are displayed upon selecting Show MP Image or Show AP Image of Action SW on the work sheet. Also, when the automatic deletion function of the CD- measurement data file is activated, the image file related to the deleted CD-measurement data file will also be automatically deleted. 5-4
  • 70. 6.1 6. COORDINATE SCHEMES6.1 GeneralThe following two coordinate schemes are provided in this system:(1) Stage coordinate scheme(2) Wafer coordinate schemeThe stage coordinate scheme is used to indicate mechanical coordinates of the specimen stage.In the wafer coordinate scheme, the user can specify on-wafer coordinates after completingrelational calibration with the stage coordinate scheme.6.2 Stage Coordinate SchemeThe specimen stage of this system is driven on X and Y axes. Table 6-1 shows the movablerange and minimum drive step of each axis. Table 6-1 Movable Range and Minimum Drive Step Axis Movable Range Minimum Drive Step X (horizontal) 0 to 200 (150) mm* 0.25 mm Y (vertical) 0 to 200 (150) mm* 0.25 mmThe X and Y stage coordinate positions are always indicated on the stage control panel.Each coordinate value is represented in dimensional unit of µm.With the orientation flat side facing down, the X axis corresponds to the horizontal direction andthe Y axis corresponds to the vertical direction.The stage movable range on the X and Y axes is 0 to 200 mm, or else 0 to 150 mm *.Note, however, that the stage may not be movable in 20 µm region near the travel limits of 0 mmand 200 mm because of calibration of stage distortion.* Stage movable range is 0 to 150 mm for S-8620 with serial no. 86xx-xx and serial nos. up to 8342-xx. 6-1
  • 71. 6.3 Wafer Coordinate Scheme6.3 Wafer Coordinate SchemeFor indicating wafer coordinate points, the following two kinds of values are specifiable.(1) Chip number and on-chip coordinates(2) Wafer coordinatesBefore using the wafer coordinate scheme, it is necessary to predefine chip pitch and array usingthe IDW and IDP Editors. Also, alignment with the stage coordinate scheme is required asmentioned in 6.4.6.3.1 Chip Number and On-Chip CoordinatesIt is assumed that chips having identical configuration are arranged in a form of array. Each chipon wafer is indicated using a combination of chip number X in horizontal direction and chipnumber Y in vertical direction.Figure 6-1 shows the default setting of wafer coordinate scheme. The origin of wafer coordinatescheme is located at the lower left corner with the orientation flat or V-notch side facing down.A chip at this position is referred to the origin chip and it is indicated by chip number (0, 0).In most cases, the origin chip does not exist on wafer actually. It is also allowed to assign anyother chip as the origin chip using the IDW Editor.On each chip, the on-chip coordinate scheme is formed with the lower left corner of chip taken asthe origin point. In this scheme, the X axis corresponds to the horizontal direction, and the Yaxis corresponds to the vertical direction. Any pattern position on chip can be specified indimensional unit of µm on X and Y axes. Chip (X, Y) = (4, 6) Wafer ROW Chip (X, Y) = (6, 4) On-chip origin (0, 0)Origin chip(X, Y) = (0, 0) On-chip coordinates COLUMN Origin (0, 0) Wafer coordinates Orientation flat (OF) (or V-notch) Fig. 6-1 Wafer Coordinate Scheme 6-2
  • 72. 6.3.26.3.2 Wafer CoordinatesIn Fig. 6-1, the on-chip coordinate origin of the origin chip corresponds to the origin point of wafercoordinate scheme. Any wafer coordinate position can be represented by a combination ofX-direction and Y-direction values with respect to this origin point. The wafer coordinate X and Yvalues are related with the chip numbers and on-chip coordinates as shown below.(Wafer coordinate X value) = (Chip number X) ´ (X direction pitch of chip) + (On-chip coordinate X value)(Wafer coordinate Y value) = (Chip number Y) ´ (Y direction pitch of chip) + (On-chip coordinate Y value) 6-3
  • 73. 6.4 Wafer Alignment6.4 Wafer AlignmentFor using the wafer coordinate scheme, it is required to establish positional relationship with thestage coordinate scheme. At each exchange of wafer, enter two relational points; the first andsecond alignment points. The two chips to be used for alignment are referred to as the first andsecond alignment chips. Demonstrated below is an example of manual alignment.For determining where alignment is to made, use the AP Chip Select screen shown in Fig. 6-2.This AP Chip Select screen can be called up from the IDP Editor. Before creating an IDP file,enter such parameters as chip array and chip size using the IDW editor. Chip display areaChip number input Alignment chip countfield indication field Fig. 6-2 AP Chip Select 6-4
  • 74. 6.4The wafer alignment procedure is described below. 1500 mm 1st alignment position Approx. (19000, 69000) in stage coordinate scheme 1500 mm 100 mm 100 mm On-chip coordinate origin Y ROW 2nd alignment chip (6, 3) COLUMN (0, 0) Wafer coordinates Wafer 1st alignment chip Stage coordinate origin coordinate (0, 3) origin X (0, 0) Stage coordinates Fig. 6-3 Stage Coordinates and Wafer Coordinates(1) Move the specimen stage to the first alignment position. Open the Stage Controller screen, and click ‘1st Move’ button of Wafer Alignment. Then, the specimen stage will be moved to the approximate alignment position. If it is difficult to find out the alignment pattern, select the optical microscopical (OM) image. Set the alignment pattern at the approximate center of screen.(2) Enter the first alignment position. On the Stage Controller screen, click ‘1st Reg’ button of Wafer Alignment. The cross cursor will then appear. Bring this cursor to the alignment position, and then click OK button.(3) Enter the second alignment position. In the same manner as for the first alignment position, click 2nd Move button and then Reg button on the Stage Controller screen. When the second alignment position is determined, the wafer alignment procedure is completed. 6-5
  • 75. 6.5 Visual Field Shift in Each Coordinate Scheme6.5 Visual Field Shift in Each Coordinate SchemeThe visual field can be shifted in the stage coordinate scheme or the wafer coordinate scheme. Map operation window start button Stage coordinate display area Memory drive area Absolute value drive area Relative value drive area Wafer alignment area Special position drive area Fig. 6-4 Stage Controller(1) Stage Coordinate Control Operation Absolute Move : Movement according to the specified absolute position in the stage coordinate scheme. Relative Move : Movement according to the specified relative shift value in the stage coordinate scheme. Special ALP : Brings the stage to axial alignment specimen position. CLP : Brings the stage to the CD-measurement calibration specimen position. STP : Brings the stage to the astigmatism correction specimen position. Memory Action : Brings the stage to any memorized position. 6-6
  • 76. 6.5(2) Wafer Coordinate Control Operation On the Stage Controller screen shown in Fig. 6-4, click Map Operation button. Then, the Map Operation screen will appear as shown in Fig. 6-5. Before using this screen, it is necessary to load the IDW and IDP files into the system memory. On the Map Operation screen, the stage can be moved by specifying a combination of chip number and on-chip coordinate point. Also, it is allowed to reach a CD-measurement point specified in the IDP file. Stage drive area Map display area Display Area Drive Mode Selection Display Mode Selection Fig. 6-5 Map Operation 6-7
  • 77. 7.1.1 7. STARTUP AND SHUTDOWN OF INSTRUMENT7.1 Startup7.1.1 Usual Startup ProcedureThis SEM’s evacuation system (ion pump and evacuation control mechanism) and electron gunHV power supply section are powered continuously under normal conditions. When initiatingroutine instrument operation (warm start), take the following startup procedure.When restarting the instrument after it has been stopped completely (cold start), refer to section7.1.2 or 7.1.3.(1) Power-on Turn ON the STAGE and SEM power switches on the display. Precaution at Power-on: When STAGE and SEM power is turned on, do not operate keys until the message “Console Login:” appears. If Esc (Escape) or another key is pressed during instrument startup, the instrument start program will be interrupted and the instrument may fail to start. If the program is accidentally interrupted, carry out the following procedure to restart the instrument. (1) Turn OFF SEM of the display power switches. (2) A peeping sound will be heard to indicate changeover to the backup power supply. Wait about 5 minutes for the peeping sound to disappear after the backup power is used up. (3) Turn ON SEM of the display power switches again. Then carry out the procedures from (2) below.(2) Upon turning on the above switches, the message “Console Login:” will appear. Now enter “cdsem” and the system program is automatically loaded and the user login screen appears. But if a wafer is already in the system at power-on, then the wafer must be returned to the cassette. A message indicating this will appear, and the login screen won’t appear until the wafer returns to the cassette. This is explained at the “initial” section of the window operation. 7-1
  • 78. 7.1 Startup(3) Login The message “Console Login:” will appear. Enter “cdsem” and the user login screen shown in Fig. 7-1 will appear automatically. So move the cursor to the relevant item, key in a user name and press the Return key. Key in a password in the same way. User login name entry area Password entry area Fig. 7-1 User Login Screen Note on Instrument Startup: If any error occurs at startup of the system (except when a wafer is already set), the system does not perform normal operation. In this case, carry out logging-in through the User Login screen and then stop the system as described in Section 7.2. Thereafter, check suspect points that might have caused the error. If the error cannot be removed even after restart of the system, notify the qualified service engineer. 7-2
  • 79. 7.1.2 When the user name and password are correctly entered, the work manager screen shown in Fig. 7-2 will appear at the bottom of the CRT. The usable functions vary with the user name. There are three user levels -- Operator, Staff and Manager. If login is not made at Staff or Manager level, then file editing and the like cannot be done. And if “emi” is logged in for both user name and password at shipment of the instrument, then login can be made at Manager level. In other cases, the instrument should be used after having the manager carry out the user registration. Fig. 7-2 Work Manager Screen7.1.2 Startup from Complete ShutdownTake the following steps for turning on power from a completely stopped status.(1) Make sure the power switch on the user’s switchboard is turned ON.(2) Make sure the MAIN switch on the power supply unit is OFF (flipped down). If turned ON, then turn the MAIN switch to OFF and push in the white section of each switch.(3) Turn ON the MAIN switch while holding down the PUSH switch. Next turn ON the IP/FL POWER, STAGE POWER, DISPLAY POWER, RP2 POWER, RP1 POWER and EVAC POWER switches.(4) Turn ON (flip up), one at a time, the IP1, IP2 and IP3 ion pump power switches on the power supply unit (do not turn on these three switches simultaneously).(5) Turn ON the IP/HV and EVAC power switches of the display section.(6) While watching the ION-PUMP meter on the evacuation system control panel (main unit), press, one at a time, the RESET switches of IP1, IP2 and IP3. If the IP1 to IP3 lamps do not come on (or repeat coming on and then going off 5 times in succession), then press the RESET switch again (do not press the three RESET switches simultaneously). The ion pumps should then start. If they still do not start, then contact the service agent. The instrument is evacuated automatically. Check if the normal status given in the following table is attained. 7-3
  • 80. 7.1 Startup Table 7-1 Normal Status of Evacuation System Check Item Normal Status Remarks -7 IP1 vacuum degree < 2 5 10 Pa Check meter reading on evacuation (electron gun chamber) IP1 lamp lit control panel. -6 IP2 vacuum degree < 5 5 10 Pa " (intermediate chamber) IP2 lamp lit -5 IP3 vacuum degree < 5 5 10 Pa " (condenser lens) IP3 lamp lit -3 Pe1 vacuum degree < 6 5 10 Pa " (specimen chamber) Pi1/Pe1 lamps lit -2 Pe2 vacuum degree < 1 5 10 Pa " (loader chamber) Pi2/Pe2 lamps lit TMP1 TMP1/NORM lamps lit " TMP2 TMP2/NORM lamps lit " RP1, RP2 Lamps lit " AV4, AV6 to AV8 Lamps lit " AV3 Lamps lit or extinguished " Valves other than above Lamps extinguished " APS Lamp lit " Air pressure 600 to 880 kPa Check pressure gauge of air piping provided by customer. N2 gas pressure 400 to 880 kPa " Vacuum source 13 to 40 kPa "(7) Start the instrument by the procedure in 7.1.1.(8) Apply the electron beam. But if the electron gun has not been evacuated by the ion pumps for 24 hours or longer, then baking will be necessary. Following is the procedure for beam application. Click HV Controller on the Maintenance pull-down menu of the work manager screen. Select ON of the HV Controller screen. The initial values of filament current, accelerating and extracting voltages will now be applied. The microscope requires about 40 minutes until the electron beam stabilizes. Be sure to carry out axial alignment after finishing this section. Refer to section 8 for the axial alignment. 7-4
  • 81. 7.1.3 Startup After Recovery from Power Failure or Emergency StopWhen the instrument has been completely stopped by a power failure or by operation of theemergency stop switch, although the system power supply is turned off, power is supplied to theworkstation for about 5 minutes from the backup power supply for file protection. An intermittentpeep sound is generated during this period to inform the operator that the backup power supply isoperating. To restart the instrument after recovery from the power failure or emergency stop,take the following procedure.(1) Turn OFF all the breakers and switches on the power supply unit.(2) If the instrument has been stopped by the emergency stop switch, turn this switch rightward to its original position.(3) Make sure the backup power supply has stopped and the peep sound is no longer emitted. The backup power supply operates for about 5 minutes after the instrument comes to a complete stop.(4) Carry out steps (1), (2) and (3) in 7.1.2.(5) Turn ON the IP/HV and STAGE power switches of the display section.(6) The specimen stage is initialized.(7) Turn ON the EVAC and SEM power switches of the display section.(8) Carry out steps (2) and (3) in 7.1.1.7.2 Shutdown of Instrument7.2.1 Normal ShutdownAt shutdown, be sure to remove the wafer from the instrument.(1) Select Shutdown on the Maintenance menu of the work manager screen.(2) Select Normal on the Shutdown window and click Execute. A message asking whether it is okay to execute will appear on the screen. By pressing the OK button, the normal shutdown procedure will start.(3) After the SEM power is turned OFF, turn OFF the stage power. NOTICE: After complete shutdown of the instrument, be sure to close the main valve of the vacuum source connected with the instrument. 7-5
  • 82. 7.2.2 Complete Shutdown of InstrumentAt shutdown, be sure to remove the wafer from the instrument.(1) Select Shutdown on the Maintenance menu of the work manager screen.(2) Select Total on the Shutdown window and click Execute. By pressing the OK button in response to the inquiry, the shutdown procedure will start.(3) After the SEM power is turned OFF, turn OFF the STAGE, EVAC and IP/HV switches on the power switch panel.(4) Turn OFF (flip down) the IP1, IP2 and IP3 switches on the ion pump power supply.(5) Turn OFF (flip down) the OUTER BAKE POWER and INNER BAKE POWER switches on the power supply unit.(6) Turn OFF (flip down) the EVAC POWER, RP1 POWER, RP2 POWER, DISPLAY POWER, STAGE POWER, IP/FL POWER and MAIN switches on the power supply unit.(7) Turn OFF the power switch on the switchboard to cut off power to the instrument.(8) With the above procedure the instrument is completely stopped. But to avoid airleak to the instrument, do not stop the air source prepared by the customer. NOTICE: After complete shutdown of the instrument, be sure to close the main valve of the vacuum source connected with the instrument. 7-6
  • 83. 7.2.3 NOTICE: The following is essential for complete shutdown of the instrument. Be sure to take this procedure. Prerequisite for ShutdownFor completely shutting down the instrument and stopping the air source, attach the furnishedclamp to the AV-1 cylinder in order to maintain the electron gun vacuum Air tubes Clamp AV-1 cylinder Lock nut Column Fig. 7-3 AV-1 Cylinder Area7.2.3 Shutdown at Power FailureCarry out steps (3), (4), (5), (6) and (7) in 7.2.2 for complete shutdown of the instrument.(But note that even if these switches are not turned off, automatic reset will not be made at powerrecovery.) 7-7
  • 84. 8.1.1 8. IMAGE ADJUSTMENT8.1 Optical Microscope ImageThe optical microscope is used for observing a wafer at low magnification. Since the opticalmicroscope image provides a better S/N ratio than a low-mag SEM image, it is easier to locate theposition of the pattern to be measured. The magnification and visual field with an opticalmicroscope image are as follows. Magnification Approx. 5110 (fixed magnification) Visual field Approx. 1.2 mm 5 1.2 mm8.1.1 Adjustment of Optical Microscope (OM) Image(1) Select Image Operation (Fig. 8-1) from the work manager menu (Fig. 7-2), and select OM from the Image menu.(2) Select Stage Controller from the work manager menu, and move the stage to the wafer pattern position.(3) Select Beam Cont... (Fig. 8-2) from the Image Operation screen, and the Beam Controller screen will open. Click OM LUX and adjust image brightness with the OM LUX slide bar.(4) Adjust the focus with the focus-adjusting slide bar on the Image Operation screen. 8-1
  • 85. 8.1 Optical Microscope Image Image selection Cursor control Image display Beam setting Focus adjustment slide bar Fig. 8-1 Image Operation Screen OM LUX slide bar OM LUX Fig. 8-2 Beam Controller Screen 8-2
  • 86. 8.1.28.1.2 Auto Adjustment of Optical Microscope (OM) Image(1) Select Image Operation (Fig. 8-1) from the work manager menu (Fig. 7-2), and select OM from the Image menu.(2) Select Stage Controller from the work manager menu, and move the stage to the wafer pattern position.(3) Select Beam Cont... (Fig. 8-3) from the Image Operation screen and the Beam Controller screen will open. Click Ref of the OM autoillumination adjusting reference and specify the degree of illumination. This is settable in a range of 1 to 5, with 5 providing the maximum brightness and 1 the minimum. Click Auto of B. & C. and the illumination is adjusted automatically.(4) Click Focus Auto (Fig. 8-4) at the lower part of the Image Operation screen, and the focus will be adjusted automatically. OM auto illumination adjustment Reference for OM auto illumination adjustment Fig. 8-3 Beam Controller Screen Auto focus button Fig. 8-4 Image Operation Screen Notes: 1. When there are not many features on the sample image on the screen, the accuracy of auto focusing may be inadequate. 2. A large deviation in focus may indicate that the auto focus is not activated. In such case, first make a coarse adjustment with the focus-adjusting slide bar and then execute the auto focus. 8-3
  • 87. 8.2 Condition Setting for SEM Image8.2 Condition Setting for SEM ImageCondition setting for the SEM image obtained with the electron beam consists of acceleratingvoltage and probe current settings. First the accelerating voltage is set, followed by the probecurrent.(1) Select Image Operation from the work manager menu (Fig. 7-2), and click HV... on the Image Operation screen. As shown on the screen below (Fig. 8-5), enter the normally used accelerating voltage at Set Vac using the keyboard (800 V for example).(2) Next select the probe current range normally used at that accelerating voltage. High, Middle and Low of Ip Mode indicate the probe current levels, and following are the approximate ranges of each. High : 7 to 12 pA Middle : 4 to 7 pA Low : 2 to 4 pA Click the appropriate probe current level, and carry out axial alignment with Alignment 1 and 2. (Refer to 8.3.5 and 8.3.6 for this axial alignment.) When power is turned on after shutdown, be sure to set up the Ip Mode again. By clicking Ip Range, the actual probe current range for the selected level is automatically measured and indicated.(3) Finally enter the probe current to be used at Set Ip using the keyboard (5 pA for example). A current value within Ip Range is settable at Set Ip. Fig. 8-5 HV Setup Screen(4) Axial alignment of electron gun is done in Middle Ip Mode before the instrument is shipped. To use High or Low mode in step (2) above, axial alignment of electron gun is required. (For details of axial alignment, refer to 8.3.2-Axial Alignment of Electron Optics.) 8-4
  • 88. 8.3.18.3 Axial Alignment of Electron Optics8.3.1 Axial Alignment of Electron OpticsThe extent of axial alignment of the electron optics varies with the condition at that particular time.Select and carry out appropriate steps of alignment. Fig. 8-6 shows the overall flow of electronoptics axial alignment and the criteria for alignment step selection. After taking any alignmentstep, be sure to carry out all of its subordinate (lower-priority) steps. Axial alignment steps l After baking Electron gun axial alignment Higher l After tip replacement priority l When desired probe current is not obtained upon changing accelerating voltage (Set Vac) Mechanical Condenser lens1 alignments axial alignment Condenser lens2 axial alignment Objective movable aperture l After exchanging objective axial alignment movable aperture Axial alignment using l When Ip Mode is changed Alignment 1 l When accelerating voltage (Set Vac) is changed l When good SEM image is not obtainable through axial alignment Electrical with Alignment 2 after changing alignments probe current (emission current) Axial alignment using l When probe current (emission current) is Alignment 2 changed. Stigmator coil axial alignment Lower Registration of SEM priority condition memory data End Fig. 8-6 Overall Flow of Electron Optics Axial Alignment 8-5
  • 89. 8.3 Axial Alignment of Electron Optics8.3.2 Axial Alignment of Electron Gun (carried out by service engineers only)(1) Remove the front cover from the column.(2) Attach four axial alignment knobs (furnished as accessories) to the electron gun assembly. Electron gun alignment knob (´ 4) Fig. 8-7 Attachment Positions of Axial Alignment Knobs(3) Click ALP on the Stage Controller screen to move the specimen stage to the alignment specimen position.(4) Turn off excitation condenser lenses 1 and 2 (detach the connectors).(5) Open the objective movable aperture (set to ‘0’).(6) Click Align. Clear on the Beam Controller screen, and the electrical alignment is cleared.(7) Key in a desired accelerating voltage at Set Vac on the HV Setup screen (800 V normally). Then select Middle of Ip Mode.(8) Set magnification to a minimum ( 5600), and adjust focus with FOCUS knob or the Coarse/Fine slide bar on the Image Operation screen.(9) Set B. & C. on Beam Controller screen to Manual. Select B. & C. and adjust the brightness and contrast.(10) Turn the electron gun alignment knobs to obtain the brightest grid image.(11) Click None on Beam Controller screen.This completes the axial alignment of the electron gun. Proceed to axial alignment of thecondenser lens. 8-6
  • 90. 8.3.38.3.3 Axial Alignment of Condenser Lens 1 and 2 (carried out by service engineers only)(1) Axial alignment should be performed in the order of condenser lenses 1 and 2. Attach the COND.1 connector.(2) Set magnification to minimum level and adjust focus with FOCUS knob or with the Coarse/Fine slide bar of Image Operation screen.(3) Turn the condenser lens alignment knobs and obtain the brightest grid image.(4) Set magnification to 52000 and adjust focus as in step (2).(5) Click Alignment 2 on the Beam Controller screen.(6) Turn the condenser lens alignment knobs to minimize the SEM image movement (image will move concentrically).(7) Click None on the Beam Controller screen. Attach the COND.2 connector, and carry out adjustment starting from step (2).(8) This completes the axial alignment of the condenser lens. Proceed to axial alignment of the objective movable aperture.8.3.4 Axial Alignment of Objective Movable Aperture(1) Set B. & C. on Beam Controller screen to Auto. Click Align. Clear to clear the electrical alignment.(2) Set the movable aperture select knob to one of 1 to 4.(3) Set magnification to minimum level.(4) Adjust the focus.(5) Click Alignment 2 on the Beam Controller screen.(6) Using the objective movable aperture fine adjust knobs X and Y, minimize the image movement on the CRT (so image will move concentrically).(7) Click None on the Beam Controller screen.(8) Set magnification to 550000.(9) Repeat steps (4) to (7) above. 8-7
  • 91. 8.3 Axial Alignment of Electron Optics8.3.5 Axial Alignment Using Alignment 1This is an electrical alignment, and is used when changing accelerating voltage or Ip Mode.(1) Click Align. Clear on the Beam Controller screen.(2) Click Alignment 1 on the Beam Controller screen.(3) Set magnification to minimum level. Adjust X, Y slide bar on the Beam Controller screen so the bright part through which the beam has passed comes to the screen center (Fig. 8-8). Fig. 8-8 Axial Alignment Using Alignment 1(4) After the adjustment, click None on the Beam Controller screen.(5) Proceed to axial alignment using Alignment 2. Fig. 8-9 Beam Controller Screen 8-8
  • 92. 8.3.68.3.6 Axial Alignment Using Alignment 2(1) Carry out focusing on the sample.(2) Click Alignment 2 on the Beam Controller screen.(3) Using the X, Y slide bar on the Beam Controller screen, minimize the movement of SEM image (so image will move concentrically).(4) Gradually increase magnification from minimum level to about 510000 while adjusting.(5) After the adjustment, click None on the Beam Controller screen.8.3.7 Axial Alignment of Stigmator Coil(1) Carry out focusing on the sample.(2) Click Stigma Align.X/Stigma Align.Y on the Beam Controller screen.(3) Using the XX, XY (YX, YY) slide bar on the Beam Controller screen, minimize the movement of the SEM image.(4) Adjust at a magnification of minimum level to 55000.(5) After adjustment with Stigma Align.X, click Stigma Align.Y and minimize the movement of SEM image in the same way.(6) Click Alignment 2 on the Beam Controller screen and check if the image movement is minimum. If not minimized, repeat adjustment with Alignment 2, Stigma Align.X and Stigma Align.Y until the movement is minimum.(7) After the adjustment, click None on the Beam Controller screen.8.3.8 Astigmatism Correction(1) Manual Adjustment Astigmatism is corrected by means of the STIGMA knob on the control panel. —STIGMA— FOCUS -STIGMA- FOCUS Fig. 8-10 Positions of STIGMA and FOCUS Knobs 8-9
  • 93. 8.3 Axial Alignment of Electron Optics (2) Auto Stigma To carry out the auto stigma function, click AST button on the Beam Controller screen. Before execution of this function, be sure to perform axial alignment as in 8.3.1. For this purpose, click STP button on the Stage Controller screen to set up the astigmatism compensation specimen position. During execution of the auto stigma sequence, the image is frozen and its magnification is switched to 50k (display remains unchanged). When the auto stigma sequence is completed, the magnification is restored to the original level (which has been selected before execution). 8.3.9 Focusing (1) Manual Focus Adjustment Focus is adjustable by means of the FOCUS knob on the control panel or by the slide bar on the Image Operation screen. In the latter case, click Coarse to make a coarse adjustment and Fine to make a fine adjustment.Image selection High voltage setting Magnification setting Beam setting Focus-adjusting slide bar Fig. 8-11 Image Operation Screen 8 - 10
  • 94. 8.3.9(2) Auto Focus Adjustment Click Focus Auto at the lower part of the Image Operation screen to execute autofocusing. Note that if the image showing contrast is too small, the autofocusing may not work properly, so it is recommended to adjust the magnification until the contrast portion takes up at least 1/4 of the screen. In the case of auto measurement by way of recipe, autofocusing is executed automatically together with the autoaddressing function.(3) Manual Astigmatism Correction and Focus Adjustment Manual correction of both astigmatism and focus is explained next. In this case the image will appear as in the photos upon adjusting the focus. First, set an entire-image-defocused state before the astigmatism correction. Partially focused Entire image Partially focused defocused Fig. 8-12 Images with Astigmatism and Defocused Next adjust the stigmator knobs until the image becomes clear. And carry out focusing by the aforementioned method and correct the astigmatism. Repeat the adjustment until the image becomes clear. Finally adjust the focus again. 8 - 11
  • 95. 8.3 Axial Alignment of Electron Optics8.3.10 Saving/Loading of SEM Condition MemoryUp to 20 SEM condition memory areas are available. The following data can be savedcollectively into the SEM condition memory.• Accelerating voltage• Probe current Observation parameters• Probe current mode H/M/L• Retarding ON/OFF• Alignment 1 and 2 Axial alignment data• Stigma• Stigma alignmentFor saving/loading SEM condition data,click the Manager...button on the Beam Controller screen.The SEM Condition Memory Manager screen will then appear. You can save/load the SEMcondition data through this screen.Before attempting to save the SEM condition data, be sure to complete axial alignment.In SEM condition data loading, you can set up the saved observation parameters (except probecurrent value) and axial alignment data.8.3.11 Image Contrast and Brightness(1) Manual Adjustment Set B. & C. on Beam Controller screen to Manual (the pulldown menu will appear if Auto is clicked, so select Manual). Upon clicking B. & C., brightness and contrast are adjustable with the Brightness/ Contrast slide bar.(2) Auto Adjustment Set B. & C. on Beam Controller screen to Auto. The gradation of Ref is as follows. B. Ref 1 2 3 4 5 brightness Brighter C. Ref 1 2 3 4 5 contrast Higher contrast 8 - 12
  • 96. 99. TROUBLESHOOTING WARNING · Voltages up to 100 V AC and 10 kV DC are used in this instrument. Touching internal parts may result in an electric shock. · If you remove the covers of column unit, control unit and/or power unit and touch internal parts while the instrument power is turned on, there is a danger of fatal or serious injury due to electric shock. · Before handling parts inside the instrument, be sure to turn off the related power supply. If covers must be removed with the power on, do not touch parts inside the units. · If you accidentally touch moving parts inside the instrument, there is a danger of your hand being caught or else cut. · Before removing the covers and handling parts inside the main unit, be sure to turn OFF the power. · Do not touch hot sections such as oil rotary pump, turbo molecular pump, baking heater, or power unit and leak valve inside the instrument, or you may be burned. · Before handling hot sections, be sure to turn OFF the related power supply and wait until the part cools down sufficiently. · Particularly when replacing the oil in the rotary pump, there is a danger of the oil splashing out while the pump itself is still hot. Wait until the pump cools down before replacing the oil. 9-1
  • 97. 9. TROUBLESHOOTING WARNING · If tubing is performed with N2 gas flowing out, and a large amount of the gas is inhaled, it could cause breathing difficulty, and in the worst case, could be fatal. Before carrying out tubing for the N2 gas, make sure to close the main valve for the N2 gas. · If a large amount of vaporized hexane (n-hexane) is inhaled, it may result in injury or breathing difficulty. · In a place where hexane is used, be sure to ventilate well and be careful not to inhale in a large amount. Also wear an antigas mask or the like if necessary. · Be careful not to ignite vaporized hexane because it may explode. · When hexane is used, be sure to ventilate the place well and don’t use a flame in the vicinity. · If hexane is mistakenly swallowed or comes into contact with the skin or eyes, it may affect the nervous system in various ways such as paralysis of the senses, difficulty in walking, etc. due to stimulation. · When hexane is used, be sure to ventilate the place well, and depending on the conditions, use an air aspirator, protective goggles and protective gloves and clothes. 9-2
  • 98. 9.19.1 Evacuation System Abnormalities Fault Symptom Probable Cause RemedyEvacuation system stops Power failure occurredoperating Fuse has blown Contact service engineer. Air pressure for driving valves has dropped below 600 kPa (APS lamp extinguished on evacuation control panel).Specimen chamber Leakage of airvacuum does not rise (a) Due to incomplete closing of loader(low vacuum range) chamber door (b) Due to contamination of seal face and gasket of loader chamber door Faulty Pirani gauge Contact service engineer. Faulty oil rotary pump (a) Very little (or excessive) RP oil (b) RP motor doesn’t work Malfunction of evacuation system valve Contact service engineer. (a) Air pressure drop or air leak (b) Defective valve Malfunction of leak valve (LV1)Specimen chamber and TMP performance has degraded, or normal TMP Contact service engineer.loader chamber vacuum operation impossible.does not rise(high vacuum range) Malfunction of evacuation system valve Contact service engineer. (a) Air leakage (b) Faulty valve Faulty Pirani or Penning gauge Contact service engineer. Vacuum leakage If leakage doesn’t stop, (a) Leak valve (LV1) faulty or seal face contact service engineer. contaminated (b) Seal face contaminated on loader chamber lidIntermediate chamber Faulty ion pump Contact service engineer.vacuum does not rise(high vacuum range: Vacuum leakage -3 -6 10 to 10 Pa) 9-3
  • 99. 9.2 Abnormal Specimen Stage/Loader (contd) Fault Symptom Probable Cause Remedy Electron gun chamber Faulty ion pump Contact service engineer. vacuum does not rise (ultrahigh vacuum range: Poor performance of ion pump* -5 -7 10 to 10 Pa) Vacuum leakageNoteH: When the instrument is used for a long time, the ion pump (inner wall, pump element, etc.) is increasingly contaminated and its performance is degraded. If the vacuum degree is not improved by baking the ion pump, regenerative treatment is required. When the life of the ion pump has expired, replacement of elements is required. In case the prescribed vacuum is unobtainable although neither a leak nor other cause is located, contact your service engineer.9.2 Abnormal Specimen Stage/LoaderPerform check according to Fig. 9-1.After the specimen exchange (XC) chamber is opened, the wafer transfer arm enters the XCchamber. Under this condition, if the instrument is stopped due to power failure or otherabnormality, turn power on again. At this step, initialization may not come to a normal end.In this case, open the right cover of auto loader, and press the RESET key of wafer transfercontroller. Then, after resetting in this manner, shut down the instrument and turn power onagain.If a wafer is placed on the transfer arm, press the STOP key when the arm comes to a properposition after resetting. Then, after removing the wafer, press the RESET key again. RESET KEY STOP KEY Wafer Transfer Controller 9-4
  • 100. 9.2 (1) Torque fluctuation due to contamination of guide sliding face Stage defective (2) Abrasion of wafer holder guide bearing (3) Abrasion of sliding face Malfunction (1) Stepping motor of stage (2) Increase in backlash of ball screw (3) Backlash/damage of lateral coupling (4) Torque increase due to contamination with oil Stage drive (5) Abrasion of ball screw bearing mechanism defective (6) Increase in output torque of magnetic seal (7) Looseness of stage joint (8) Backlash of linear guide/insufficient pre-load (9) Malfunction of limit switch (1) Stepping motorFailure of (2) Increase in backlash of ball screwstage/ (3) Backlash/damage of lateral couplingloader (4) Torque increase due to contamination with oil Drive mechanism (5) Abrasion of ball screw bearing defective (6) Increase in output torque of magnetic seal (7) Backlash of linear guide/insufficient Pre-load (8) Malfunction of limit switch (1) Malfunction of air cylinder (2) Expiration of bellows life (3) Abrasion of packing for seal Loader or air Malfunction lock improper (4) Abrasion of drive shaft and link plate of loader (5) Defective limit switch (6) Malfunction of solenoid valve for air Wafer holder (1) Abrasion of bearing in chuck section chuck/unchuck improper (2) Malfunction of solenoid valve for air (3) Defective photointerrupter (4) Increase in output torque of magnetic seal Fig. 9-1 Checks on Specimen Stage/Loader 9-5
  • 101. 9.3 Abnormal SEM Image9.3 Abnormal SEM Image9.3.1 Abnormal Emission Current(1) Fluctuation of Emission Current -7 (a) Confirm that the vacuum degree of IP1 is better than 1 5 10 Pa. When the emission current fluctuates due to deterioration of vacuum in the electron gun chamber, carry out baking. Contact your service engineer. (b) Abnormal High Voltage Supply Contact your service engineer.(2) No Emission Current (image not displayed on CRT) (a) Damage of FE tip: Contact your service engineer. (b) Defective emission current meter: Contact your service engineer.(3) Fluctuation of Acceleration Voltage (Vac) Contact your service engineer.9.3.2 Absence of Image on CRT(1) Poor electron gun alignment(2) The AV1 valve won’t open. Contact your service engineer.(3) Faulty Head Amplifier If so, CRT brightness cannot be changed by turning the BRIGHTNESS knob (after mode change from AUTO to MAN). Contact your service engineer.(4) The post-stage acceleration high voltage is not applied.(5) The photomultiplier high voltage is not applied.(6) Excessively counterclockwise turning of CONTRAST knob (in manual mode)(7) Poor adjustment of FOCUS (objective lens) controls(8) The electron extracting voltage is not applied.(9) Damage of FE tip (no emission current obtained)(10) Shortage of secondary electrons due to extremely low emission current(11) The accelerating voltage is not applied. 9-6
  • 102. 9.3.3(12) Poor Adjustment of Objective Lens Movable Aperture Set the longitudinal fine control knob of the objective lens movable aperture to about midpoint and the objective lens movable aperture to position 0. If the image does not appear on the CRT yet, check further.(13) Too high magnification(14) Each vacuum degree of IP1, IP2 and IP3 does not reach the following value. S-8000 series S-7000 series -7 -8 IP1: 2 5 10 Pa IP1: 1 5 10 Pa -6 -6 IP2: 5 5 10 Pa IP2: 2 5 10 Pa -5 -5 IP3: 5 5 10 Pa IP3: 7 5 10 Pa9.3.3 Noisy Image(1) Damaged Scintillator Replace the scintillator. Contact your service engineer.(2) Astigmatism Correction Impossible Defective astigmatism correcting circuit: Contact your service engineer. (Astigmatism of the image does not change when turning the STIGMATOR (X, Y) knobs fully counterclockwise and clockwise.) The magnification should be 510,000 or so.(3) Poor centering of objective lens movable aperture(4) Dirty Objective Lens Movable Aperture Replace the objective lens movable aperture.(5) Poor Axial Alignment Retry to align the electron gun with the lens system. 9-7
  • 103. 9.4 Abnormal Optical Microscope (OM) Image9.4 Abnormal Optical Microscope (OM) Image9.4.1 Absence of OM Image(1) OM image is not selected on the image operation screen. Make changeover to OM image.(2) Improper Brightness Adjust the brightness with the OM LUX knob of the beam controller.(3) The brightness is not changed by adjusting the above knob. The lamp for OM is burnt out. Replace the lamp.(4) The specimen is not located at the optical microscope position. Move the specimen to the ALP/CLP position or the position of pattern on the wafer with the stage controller.(5) The optical microscope is out of focus. Adjust the focus on the image operation screen.9.5 Display Unit Fails(1) Blowing of Power Fuse Replace the fuse (Contact your service engineer).(2) Defective Display Unit (Contact your service engineer.) For any other trouble, contact your service engineer.9.6 Software ErrorIf the software operation is erroneous or the behavior of software seems to be abnormal, notifythe qualified service personnel of the symptom and operating conditions.In such a case, it is advisable to provide the log data containing the records of internalcommunications and operations of the computer. Using the log data, the service personnel mayfind out the cause of trouble more promptly. So, in the manner mentioned below, output the logdata onto a floppy disk and give it to the service engineer.Although the records of internal communications and operations of the computer are contained inthe log data, it does not hold the process conditions of IDW/IDP file and other condition data.Note also that the log data can contain the communication/operation records corresponding tojust a short period of approx. 10 minutes before execution of the Logging command. 9-8
  • 104. 9.6.19.6.1 How to Save Log Data onto Hard Disk (HD)The log data is retained in the main memory of the workstation. Therefore, it will be lost whenpower is turned off. First, save the log data onto the HD immediately after occurrence of atrouble in software.On the console, press the OFF button for more than three seconds repetitively three times asshown below. This button action saves the log data onto the HD. If the screen is locked, takethis procedure to carry out logging. While the log data is saved onto the HD, eight LEDindicators on the front of workstation (on the periphery of the front panel of the display) blink forseveral seconds. Make sure of blinking of these indicators. Then, restart the system in themanner described in 9.6.3. For more For more For more than 3 than 3 than 3 ON ON ON For less than For less than 2 seconds 2 seconds Execution of logging9.6.2 How to Output Log Data onto Floppy DiskAfter saving the log data onto the hard disk as instructed in 9.6.1, you can output it to a floppy disk(FD).First prepare a 3.5-inch 1.44 MB floppy disk. Then start the Utility-Accessories-Log to FD.A message confirming whether or not FD is set will appear. Remove the write protection of theFD and put it into the FD drive of the workstation. Operate according to the messages displayed,and the FD will be initialized in the specific format and the log data will be stored in it. It takesabout six minutes to output the log data onto the floppy disk. The floppy disk on which the logdata has thus been stored should be given to the service engineer.Note that just one set of log data can be stored on the floppy disk.Remember that the floppy disk is formatted before the log data is output to it. So, beforeattempting to output the log data to the floppy disk, make sure that it contains no other importantdata. 9-9
  • 105. 9.6 Software Error9.6.3 Restart After Software ErrorIf an error has occurred in the software operation for some reason, restart the system in thefollowing procedure, starting from step (1). Note that this procedure is for restarting after theoccurrence of a software error, and should not be used normally.(1) When operation can be done with mouse: (a) Select Shutdown from the Maintenance menu of the work manager. (b) Select Normal on the Shutdown window, and click Execute. A prompt will appear asking whether you want to execute, so press OK, then the termination process will start. (c) The SEM power supply will turn off automatically (see Fig. 2-11 in 2.4.2). Turn on the SEM power supply again. (d) When “Console Login:” appears, enter cdsem in succession and press the Return key. The system is restarted.(2) When key entries can be made: (a) Press Shift, CTRL and Break keys simultaneously, and the window system is terminated. (b) Enter nxshut from the keyboard and press the Return key. (c) Press CTRL and d keys together, and carry out the process twice. “Console Login:” will then appear. (d) Turn off the SEM power supply. Wait about 10 seconds, and turn on the SEM power supply again. (e) In succession to “Console Login”, appears, enter cdsem and press the Return key. The system is restarted.(3) When key entries cannot be made: (a) Turn off the SEM power supply. The display power supply will be cut off, and the system will be terminated automatically. Wait about 5 minutes for the peeping sound to end, and turn on the SEM power supply again. (b) When “Console Login:” appears, enter cdsem in succession and press the Return key. The system is restarted. 9 - 10
  • 106. 10.1.1 10. MAINTENANCE10.1 Consumables and Spare Parts10.1.1 ConsumablesThe items shown in Table 10-1 should always be on hand for normal operation. Table 10-1 Consumables Part No. Part Name Use Remarks 567-4805 Vacuum grease (Y-VAC 2) For vacuum seal Hexane (C8H14) For part cleaning Contained in 500 cc bottle, special grade 567-0995 Objective lens aperture plate For objective lens (0.02 mm in diameter 54) 567-0994 Schottky tip For electron gun 830-4183 Scintillator For SE detector Polyethylene gloves For part handling 565-1026 RP oil For direct-connection- 4 L contained, manufactured by type RP Edwards Japan, Co. (*) 566-1588 RP alumina (H02600050) For foreline trap Contained in 0.45 kg can(*) 545-1214 Grease For lubrication of drive 20 g contained parts in vacuum 567-6514 Thermal paper For printer 567-1488 Halogen lamp For optical microscope 567-3307 Fixed aperture Located at the lower (0.7 mm in diameter) part of AV1 valve(*) These items are required only when a rotary pump is used for pre-pumping. 10 - 1
  • 107. 10.2 Cautions on Maintenance10.1.2 Spare PartsThe items shown in Table 10-2 must be prepared for long-term operation. Select a properquantity in consideration of the application of each part. Table 10-2 Spare Parts Part No. Part Name Use Remarks K439000 Penning gauge For vacuum level indication 567-6553 EWS backup power supply For protection of workstation 271-3162 CPU backup battery For data memory 567-6673 Mouse For workstation operation 567-0881 Solenoid valve (upper) For evacuation valve operation 567-0882 Solenoid valve (lower) For evacuation valve operation 580-4614 Air filter For filtering at N2 leakage 567-2437 Standard reference specimen For axial alignment 567-0942 Laser diode unit For Z sensor 567-3374 Load-lock transfer arm For wafer transfer For S-8840/S-864010.2 Cautions on MaintenanceSpecialists will take charge of maintenance when contracted separately. However, formaintaining the specifications and performance of the instrument, the following cautions must beobserved in addition to the precautions given at the beginning of this manual.(1) The customer is not allowed to disassemble the components (other than permitted in the instruction manual) or modify them. Otherwise the original performance might not be available again.(2) Do not allow dust, particularly metal powder to enter the inside of each component.(3) Do not give strong shocks or vibrations to the mainframe. 10 - 2
  • 108. 10.310.3 Periodic InspectionTable 10-3 lists check items required for operating the instrument normally. For details ofcheck, contact your service engineer. It is recommended to make a contract on maintenance service. Table 10-3 Periodic Check Responsible personnel: , and indicate user, Hitachi’s service engineer and unit venders engineer respectively. Frequency of No. Check Item Responsibility Remarks Check 1 Daily 1. Cleaning: (at startup) Outside of loader chamber, instrument table, etc. 2. Check of vacuum degree, air pressure and N2 gas pressure 3. Calibration of measuring accuracy Every 6 to 8 hours Check of vacuum degree, air pressure and N2 (at shutdown) gas pressure 2 Weekly Check of electron-optical axis 3 Monthly 1. Cleaning: Exterior of instrument and control panel 2. Check of electron-optical axis 3. Check of RP oil volume 4 Every 1.5 months Change of objective movable aperture selector 5 Biannually 1. Lubrication to stage drive mechanism At charge* 2. Replacement of objective movable aperture plate 3. Check and greasing of evacuation valves At charge* 4. Replacement of RP oil 5. Replacement of alumina in foreline trap for RP 6. Maintenance of keyboard, mouse and At charge* printer 7. Cleaning inside loader chamber (including At charge AV3 and arm rotating mechanism.) 6 Every 9 months 1. Replacement of electron gun cathode At charge 2. Replacement of fixed apertures of electron At charge optics 7 Yearly 1. Replacement of scintillator At charge 2. Replacement of standard specimen At charge 10 - 3
  • 109. 10.3 Periodic Inspection (contd) Frequency of No. Check Item Responsibility Remarks Check 8 Biennially 1. Replacement of airlock valve (AV1, LV1) At charge 2. Replacement of solenoid valve unit At charge 3. Replacement of hard disk in computer At charge 4. Replacement of keyboard for computer At charge 5. Replacement of air filter At charge 6. Replacement of control CRT At charge 7. Replacement of uninterruptible power At charge supply for EWS 8. Check and greasing of auto loader At charge 9. Check and greasing of orientation flat At charge sensor 10. Replacement of backup power supply for At charge ion pumpNote *: Check Item 1, 3 and 6 in No. 5 above will be carried out at charge at more than 1 year after installation.10.3.1 Evacuation System(1) Check of Vacuum Degree Normal status (evacuated status) of the evacuation system is as listed below. Table 10-4 Normal Status of Evacuation System Check Item Normal Status Remarks -7 IP1 vacuum degree < 2 5 10 Pa Check meter reading on evacuation control panel. (electron gun chamber) IP1 lamp lit -6 IP2 vacuum degree < 5 5 10 Pa Check meter reading on evacuation control panel. (1st intermediate chamber) IP2 lamp lit -5 IP3 vacuum degree < 5 5 10 Pa Check meter reading on evacuation control panel. (2nd intermediate chamber) IP3 lamp lit -3 Pe1 vacuum degree < 6 5 10 Pa Check meter reading on evacuation control panel. (rear part of specimen chamber) -2 Pe2 vacuum degree < 1 5 10 Pa Check meter reading on evacuation control panel. (lower part of loader chamber) Air pressure 490 kPa to 880 kPa Check pressure gauge of air piping provided by N2 gas pressure 392 kPa to 880 kPa customer. Vacuum source pressure 13 kPa to 40 kPa(2) Maintaining Ultrahigh Vacuum in Electron Gun Chamber If the normal vacuum degree shown in Table 10-4 is unavailable, request the service engineer for baking of the electron gun chamber.(3) Maintaining High Vacuum in Specimen Chamber and Loader Chamber If the normal vacuum degree shown in Table 10-4 is unavailable, contact the service engineer. 10 - 4
  • 110. 10.3.2(4) Maintenance of RP Periodically carry out maintenance of the RP with reference to 10.3.4.10.3.2 Replacement of Objective Movable Aperture WARNING · If a large amount of vaporized hexane (n-hexane) is inhaled, it may result in injury or breathing difficulty. · In a place where hexane is used, be sure to ventilate well and be careful not to inhale in a large amount. Also wear an antigas mask or the like if necessary. · Be careful not to ignite vaporized hexane because it may explode. · When hexane is used, be sure to ventilate the place well and don’t use a flame in the vicinity. · If hexane is mistakenly swallowed or comes into contact with the skin or eyes, it may affect the nervous system in various ways such as paralysis of the senses, difficulty in walking, etc. due to stimulation. · When hexane is used, be sure to ventilate the place well, and depending on the conditions, use an air aspirator, protective goggles and protective gloves and clothes.(1) Select EVAC controller from Maintenance of the work manager.(2) Click the SC-AIR button of the EVAC controller window.(3) Wait 20 minutes until the aperture cools down to near the room temperature.(4) N2 gas is automatically introduced into the specimen chamber and loader chamber. The procedure is finished when the lid of the specimen exchange chamber opens.(5) During automatic operation in step (4) above, remove the front cover of the microscope column.(6) Remove the four M6 screws which retain the flange of the aperture assembly, disconnect the heater power cable, and pull out the entire assembly slowly while keeping it horizontal (see Fig. 10-1). 10 - 5
  • 111. 10.3 Periodic Inspection(7) Place an aluminum foil of about 20 5 20 cm on a table. All parts removed in the following steps should be placed on the foil.(8) Remove the aperture support retaining screws with a watchmaker’s screwdriver (the second smallest one). Aperture support Aperture plate (P/N 567-0995) Aperture support Aperture support Flange retaining screw retaining screw Up Aperture holder Flange Down Heater power cable Fig. 10-1 Objective Movable Aperture(9) Remove the aperture support with tweezers.(10) Remove the objective aperture plate with tweezers.(11) Clean the aperture support and aperture holder by means of absorbent cotton (wound on a bamboo stick) and hexane. Cleaning should be done meticulously.(12) Take out the aperture plate from a small bottle and mount it on the aperture holder.(13) Place the aperture support on the aperture holder and slightly tighten the aperture support retaining screw. 10 - 6
  • 112. 10.3.3(14) After confirming that the aperture plate is exactly centered, securely tighten the aperture support retaining screw. Also make sure that the aperture plate is retained completely by the aperture support.(15) Insert the aperture assembly straight into the flange. Be careful not to insert the aperture assembly upside down.(16) Tighten the four flange retaining screws and connect the heater power cable.(17) Click the SC-EVAC button on the Evacuation Controller .(18) The specimen chamber and loader chamber are automatically evacuated. When the vacuum degree shown in Table 10-4 is satisfied, evacuation is completed.10.3.3 Check ListsKeep copies of the daily check list and periodic check list at an easy-to-access location near theinstrument. 10 - 7
  • 113. 10.3 Daily Check List Date Note: Check in the periodic check list must also be performed. No. Check Item 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 Lit status of IP1, 2 and 3 lamps -7 2 IP1 pressure < 2 5 10 Pa Periodic Inspection -6 3 IP2 pressure < 5 5 10 Pa -5 4 IP3 pressure < 5 5 10 Pa -3 5 Pe1 pressure < 6 5 10 Pa -2 6 Pe2 pressure < 1 5 10 Pa . 7 Air pressure = 490 kPa . 2 (5 to 9 kgf/cm ) = . 8 N 2 gas pressure . 392 kPa 2 (4 to 9 kgf/cm )10-8 9 RP oil volume 10 Cleaning of outside of loader chamber 11 Electron optics 12 Calibration of measuring accuracy Monthly Check Item No. Check Item Responsibility 1 Check of electron-optical axis Customer 2 Cleaning of exterior of instrument Customer 3 Replacement of objective lens movable aperture Customer
  • 114. Periodic Check List Enter the date of execution Date No. Frequency Check Item 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Resp o n si b i l i ty 1 Monthly Check of electron-optical axis Customer 2 Cleaning of exterior of instrument Customer 3 Check of RP oil volume Customer Every 1.5 Change of objective movable aperture selector 4 months Customer Biannually Lubrication of stage drive mechanism and Service engineer 5 retightening of its screws 6 Replacement of objective movable aperture Customer 7 Check and greasing of evacuation valves Service engineer 8 Replacement of RP oil Customer 9 Replacement of alumina in foreline trap for RP Customer Maintenance of computer keyboard, mouse and Service engineer 10 printer Cleaning inside loader chamber Service engineer At charge10 - 9 11 (including AV3 and arm rotating mechanism.) 12 Every 9 Replacement of electron gun cathode Service engineer At charge months 13 Replacement of fixed aperture of electron optics Service engineer At charge 14 Yearly Replacement of scintillator Service engineer At charge 15 Replacement of standard specimen Service engineer At charge 16 Biennially Replacement of airlock valves AV1 and LV1 Service engineer At charge 17 Replacement of solenoid valve unit Service engineer At charge 18 Replacement of hard disk in computer Service engineer At charge 19 Replacement of computer keyboard Service engineer At charge 20 Replacement of air filter Service engineer At charge 21 Replacement of control CRT Service engineer At charge Replacement of uninterruptible power supply for Service engineer 22 At charge EW S 23 Check and greasing of auto loader Service engineer At charge 24 Check and greasing of orientation flat sensor Service engineer At charge 25 Replacement of backup power supply for ion pump Service engineer At charge 10.3.3 Note: Checks in items no. 5, 7 and 10 will be charged at later than 1 year after installation.
  • 115. 10.3 Daily Check List (cassette-to-cassette auto loader) Date No. Check Item 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 Vacuum source pressure P = 13 to 40 kPa (100 to 300 Torr) Periodic Inspection (pressure gauge of air piping provided by customer) 2 Cleaning of exterior of autoloader 3 Cleaning of vacuum clamp on transfer arm Note: Absolutely avoid cleaning in items no. 2 and 3 when the autoloader is running. Otherwise the transfer robot may injure the human body or the transfer arm may be damaged.10 - 10
  • 116. 10.3.410.3.4 Rotary Vacuum Pump (option)(1) Name and Function of Each Part ² - ¬ ¯ ® ° ± Fig. 10-2 ¬ Air inlet - Gas ballast valve Prevents contamination/deterioration of oil due to condensed vapors (water/solvent). ® Pump oil inlet From here, oil is injected into the oil box. ¯ Air outlet Exhausts gas sucked through the air inlet. Kept open to atmosphere. ° Oil level gauge Used to check the oil volume and contamination in the oil box. ± Oil drain Discharges oil contained in the oil box. ² Carry handle 10 - 11
  • 117. 10.3 Periodic Inspection(2) Check of Oil Volume and Replacement of Oil WARNING · 100 V AC is supplied to the oil rotary pump. Touching the metallic terminal part of the power cable may result in fatal or serious injury due to electric shock. · Do not touch the rotary pump itself nor its cover while the pump is operating, or you may be burned. · Before carrying out maintenance on the rotary pump, be sure to turn OFF the EVAC power supply on the display unit and wait until the pump cools down sufficiently. To lengthen the pump life and maintain the highest performance at all times, carry out the following maintenance and inspection. Table 10-5 Maintenance and Inspection Maintenance/ Frequency Confirmation Maintenance Check Item (1) Oil level Daily The oil level must be between MIN and Replenishment of oil MAX of the level gauge. (2) Contamination of Daily Check the degree of contamination Replacement of oil oil through the level gauge. (Replace oil biannually.) (3) Clogging of filter Biannually Check the degree of filter clogging. Cleaning of filter 10 - 12
  • 118. 10.3.4 (a) Replenishment of Oil Oil inlet 1) Detach the cap of the oil inlet by turning it Air outlet counterclockwise. 2) While watching the level gauge, inject oil through the oil inlet so that the oil level is approximately 80% of the level gauge. 3) Upon completion of oil injection, securely tighten the cap by turning it clockwise. Oil drain Oil level gauge (b) Replacement of OilPump 1) Detach the cap of the drain by turning it Oil drain counterclockwise with a blade-edged screwdriver. Oil will then be drained. Oil receiver In so doing, prepare an oil receiver and Desk place it under the drain. 2) After completely draining oil, securely tighten the cap of the drain. 3) Introduce oil through the oil inlet. (c) Cleaning of Filter 1) Detach the air inlet adapter. Air inlet adapter 2) Remove the snap ring from the air inlet Snap ring with a blade-edged screwdriver. Filter 3) Remove the filter under the snap ring and eliminate contaminants from the filter. 4) Upon completion of cleaning, return the removed parts as before. 10 - 13
  • 119. 10.3 Periodic Inspection(3) Maintenance of Foreline Trap The foreline trap is intended to prevent oil from flowing backward into the vacuum container. It employs special active alumina which absorbs oil vapors and collects at least 99.9% of oil which flows backward. Snap ring d O-ring Basket e Spring Cap a Mainframe · How to Put in Alumina (FL20K) 1) Detach cap a from the mainframe by turning it counterclockwise and take out basket e. 2) Remove snap ring d from the basket with a blade-edged screwdriver and detach the aluminum cap. 3) Fill the basket with the furnished alumina to about four-fifths full. 4) Return the removed parts as before.(4) Troubleshooting If any abnormality given below occurs, trace its cause and take proper countermeasures according to the following troubleshooting table. If the abnormality persists after taking countermeasures, contact your service engineer. Symptom Check Remedy Motor does not rotate when Power supplied at primary side? Supply power at primary side. power plug is inserted into Power cord burnt out? Repair power cord. receptacle. Bearing damaged? Contact your service engineer. Stator winding disconnected? Circuit breaker is actuated. Motor heated. Contact your service engineer. Temperature sensor actuates circuit breaker Vacuum degree is deteriorated. Leak caused in piping? Locate leak and repair piping. Filter clogged? Eliminate contaminants from filter. Oil contaminated? Replace oil. Abnormal sound is emitted. Tightening bolt loosened? Tighten bolt. Bearing damaged? Contact your service engineer. Fan deformed? Temperature rises appreciably. Ventilating hole blocked? Clean ventilating hole or eliminate foreign matter from it. Fan deformed? Contact your service engineer. 10 - 14
  • 120. INDEXAAbnormal emission current ..................................................................................................... 9-6Abnormal optical microscope image ....................................................................................... 9-8Abnormal SEM image ............................................................................................................. 9-6Abnormal specimen stage/loader............................................................................................ 9-4Alignment 1............................................................................................................................. 8-8Alignment 2............................................................................................................................. 8-9Allowable vibration .................................................................................................................. 1-6Appearance of instrument system........................................................................................... 2-1Astigmatism correction............................................................................................................ 8-9Auto focus............................................................................................................................. 8-11Auto loader ........................................................................................................................... 2-15Auto Stigma .......................................................................................................................... 8-10Auto transformer ................................................................................................................... 1-14AV-1 cylinder .......................................................................................................................... 7-7Axial alignment of condenser lens........................................................................................... 8-7Axial alignment of electron gun ............................................................................................... 8-6Axial alignment of electron optics............................................................................................ 8-5Axial alignment of objective movable aperture ........................................................................ 8-7Axial alignment of stigmator coil.............................................................................................. 8-9BBeam controller screen ........................................................................................................... 8-8Brightness............................................................................................................... 2-3, 2-5, 8-12CChip number ........................................................................................................................... 6-2Consumables........................................................................................................................ 10-1Contrast .................................................................................................................. 2-3, 2-5, 8-12CPU ........................................................................................................................................ 4-1DDaily check list ...................................................................................................................... 10-8Display unit ........................................................................................................................... 2-20 Control panel.................................................................................................................. 2-23 Power supply switch....................................................................................................... 2-20 Electron gun high voltage power supply......................................................................... 2-22 Printer ............................................................................................................................ 2-24 I-1
  • 121. INDEX (cont’d)EEvacuation control panel......................................................................................................... 2-9Evacuation control unit............................................................................................................ 4-1Evacuation system abnormalities............................................................................................ 9-3Evacuation system arrangement............................................................................................. 2-8EWS ....................................................................................................................................... 4-1External electric field noise ..................................................................................................... 1-4External power noise .............................................................................................................. 1-4FFCM........................................................................................................................................ 3-3GGas source ............................................................................................................................. 1-3GUI .................................................................................................................................. 2-3, 2-5HHV control unit ........................................................................................................................ 4-1HV Setup Screen .................................................................................................................... 8-4IImage Operation screen ......................................................................................................... 8-2Image processing unit............................................................................................................. 4-1Installation layout ............................................................................................................. 1-8, 1-9Installation requirements......................................................................................................... 1-1LLine power requirements ........................................................................................................ 1-2Log data.................................................................................................................................. 9-9 I-2
  • 122. INDEX (cont’d)MMain column unit.............................................................................................................. 2-4, 2-6Map operation......................................................................................................................... 6-7OObjective movable aperture .................................................................................................... 8-5OFS control unit...................................................................................................................... 4-1On-chip coordinates................................................................................................................ 6-2Optical microscope ................................................................................................................. 8-1PPeriodic inspection................................................................................................................ 10-3 Objective movable aperture ........................................................................................... 10-5 Evacuation system ......................................................................................................... 10-4Periodic check list ................................................................................................................. 10-9RPower capacitance................................................................................................................ 1-10Retarding ................................................................................................................................ 3-2Rotary vacuum pump...........................................................................................................10-11SSchottky Emission................................................................................................................... 3-1SE electron source.................................................................................................................. 3-1SEM condition memory ......................................................................................................... 8-12SEM controller ........................................................................................................................ 4-1Shutdown of instrument .......................................................................................................... 7-6Software error ......................................................................................................................... 9-8Spare parts ........................................................................................................................... 10-2Specifications.......................................................................................................................... 2-2Stage control unit.................................................................................................................... 4-1Stage controller....................................................................................................................... 6-6Stage coordinate scheme ....................................................................................................... 6-1Stage/Evacuation control (manual) Panel ............................................................................. 2-14Stray magnetic field ................................................................................................................ 1-3System configuration .............................................................................................................. 4-1System files ............................................................................................................................ 5-1 I-3
  • 123. INDEX (cont’d)TTroubleshooting ...................................................................................................................10-14Two-stage detection system ................................................................................................... 3-4UUser files................................................................................................................................. 5-2WWafer alignment ..................................................................................................................... 6-4Wafer coordinates .................................................................................................................. 6-3Wafer transfer controller ......................................................................................................... 9-4Wiring diagram ............................................................................................................ 1-15, 1-16WT control unit ....................................................................................................................... 4-1 I-4

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