2. Background Information
5-Feb-15 Page 2
Now available from WIS, Inc., an inspection system that has
simultaneous high-throughput, double-sided inspection of photo
masks (original design). It can be easily modified to support other
substrates.
Our original concept was based on scattering measurements
from multiple lasers. The optical platform consisted of a
separate reticle chamber with controlled airflow to eliminate any
possibility of instrument-generated particle contamination. Since
that time, our concept has continuously improved to increase
sensitivity, eliminate laser diodes, and increase throughput.
Our latest Model PDS-1020G2 incorporates all these
improvements in a reduced footprint design.
6. 5-Feb-15 Page 6
PDS-1020G2 Features
• Complete Self Contained Reticle Inspection System
• Simultaneous Back Glass/Front Pellicle Inspection
• Interface/Control: Ethernet TCP/IP
• Internal Linear Stage (No Spinning of Reticle)
• Area CCD Array Provides High Sensitivity and Low
Distortion
8. 5-Feb-15 Page 8
Operating Principle
• Scattered Light from Defects Is Detected by High-Sensitivity
CCD Camera
• Background and Pattern Recognition Algorithms (option)
Minimize Pattern Clutter
• Dual-Pass Inspection Available for Maximum Sensitivity
9. 5-Feb-15 Page 9
Plug and Play Operation
• Inspection Area: Automatic or Multiple User-Definable
Regions-of-Interest
• Pellicle Frame Shape: Automatic or User-Definable
• Defect Size Classification Programmable: From 1µm to
100µm
• Size Filter: Automatic or User-Definable
• Pattern Rejection Filter: Automatic or User-Definable
(option)
• Pellicle Focus: Automatic (Range 0 to 10mm)
• Multiple Modes: Tradeoff Sensitivity vs. Throughput
(factory setup)
10. 5-Feb-15 Page 10
PDS-1020G2 Features / Benefits
• No Lasers (Therefore No Laser Safety Issues)
• No Laser Failures (Using Long-Life LEDs),
minimizing system maintenance
• No Alignment Issues Associated with Lasers
11. 5-Feb-15 Page 11
PDS-1020G2 Features / Benefits
• Airflow Exposure to Reticle Controlled by Chamber
Design
• Reticle Exposure to Ambient Is Minimized by Isolation
Compartment
• Moving Components Contained in Separate Compartment
• Electronics, Cooling and Venting Separate from Reticle
Airflow Path
• Design Minimizes Electrostatic Discharge
12. 5-Feb-15 Page 12
PDS-1020G2 Environmental Specs.
• Clean Room: Class 1
• Power: 120/240 VAC, 50/60 Hz, 200W
• Size: 38 x 33 x 69 cm
• Weight (Module): 35 kg (77 lb)
13. 5-Feb-15 Page 13
PDS-1020G2 Functional Specs.
• Mask Size: 152 x 152 mm
• Pellicle Height: 3 to 8 mm
• Inspected Surfaces: Pellicle and Back of Glass
• Inspection Area: Software Selectable
• Handling: Manual or Robotic
• Display: Host or Laptop Display
• Host Interface: Ethernet TCP/IP
• Set-Up: Menu Driven, User Programmable
• Illumination: High Intensity LEDs
14. 5-Feb-15 Page 14
PDS-1020G2 Performance Specs.
• Inspection Time (Both Sides):
20 sec. to 100 sec. (Operator Selectable)
• Repeatability
2-10 µm: > 96%
10-20 µm: > 97%
> 20 µm: > 98%
• Minimum Particle Size: ≥ 2 µm
• Spatial Resolution: 130 µm
• Position Accuracy: ± 0.25 mm
• Edge Exclusion: 2 mm
• Focus Range: 10 mm
15. 5-Feb-15 Page 15
PDS-1020G2 Software Packages
• Embedded Control Software Package – Standard
• Communicates with Host via TCP-IP Interface
• Stand-Alone Control Software Operates With Local PC
• Diagnostic Software Operates via Keyboard, Mouse and
Monitor
• Defect Analyzer for Offline Analysis of Data (option)
• Remote Control Software to Control System from Outside
Clean Room
20. 5-Feb-15 Page 20
Position and Size Repeatability
Position and Size Repeatability
Colors: indicate reported size
Dots: first inspection position
Circles: second inspection position
Arrows: particles which moved
between inspections
“new”: particles deposited between
inspections
“off”: particles removed between
inspections
NOTE: Data taken in class 10000
environment
21. 5-Feb-15 Page 21
PDS-1020G2 Front Dimensions
10.444” On Centerline
9.725” to bottom of reticle glass
surface
22. 5-Feb-15 Page 22
System Drift
0
50
100
150
200
250
300
350
400
450
500
0 5 10 15 20 25 30 35
RangeCount
Approximate Elapsed Time (min)
Timeline
0-14 Microns
15-99 Microns
20-99 Microns
• Test procedure: Multiple inspections of same photo mask in Class 1000 environment.
• Objective: To characterize system drift over time.
• Conclusion: No noticeable drift, other than expected statistical environmental drifts.
23. 5-Feb-15 Page 23
Response Uniformity
Log(Count) vs. Log(Size)
y = -1.7401x + 3.9033
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
0.00 0.50 1.00 1.50 2.00
Log(Size µm)
Log(#Particles)
• Test procedure: Inspection
of photo mask exposed to
ambient air for 2 minutes.
• Objective: To determine
uniformity of response as a
function of particle size.
• Conclusion: System
response is linear with
particle size.
24. 5-Feb-15 Page 24
Particle Density Map
1 2 3 4 5 6 7 8 9 10
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
0100200300
400
Sample Particle Density Map
300-400
200-300
100-200
0-100
• Test procedure: Inspection of
photo mask exposed to ambient air
for 2 minutes.
• Objective: To demonstrate particle
mapping capability
• Conclusion: With proper software
(not included), system can deliver
particle density map.
26. 5-Feb-15 Page 26
Counted Particles vs. Threshold
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
0 500 1000 1500 2000 2500 3000 3500
Threshold
TotalCount
• Test procedure: Inspection of
photo mask exposed to ambient
air for 2 minutes.
• Objective: To determine noise
threshold of system.
• Conclusion: Threshold can be
varied to adjust system
sensitivity to particle size.
(Note: system/ambient noise is
generally found to the left of
vertical line)
« Noise Threshold
Noise Threshold
27. 5-Feb-15 Page 27
Contact Info
Wafer Inspection Services, Inc.
www.waferinspectionservices.com
1-508-944-2851
Sales@wis-inc.net