Contamination and ESD concerns

1. 2024/1/3 ITRS Factory Integration TWG 1
ITRS 2001 Factory Integration Chapter
Electrostatic Discharge - Backup Section
Details and Assumptions for Technology
Requirements

2. 2024/1/3 ITRS Factory Integration TWG 2
Outline
 Problems Caused By Static Charge
 attraction of contamination
 electrostatic discharge (ESD) damage to devices and
photomasks
 equipment malfunction due to ESD-generated electromagnetic
interference (EMI)
 SEMI E78-0998 - Electrostatic Compatibility for
Equipment
 Conclusions

3. 2024/1/3 ITRS Factory Integration TWG 3
Static Charge Problems:
Contamination and ESD
Yield Throughput
Reticles
Equipment
Contamination Process Interruptions
Wafers
Integrated
Circuits
ESD Damage
Static Charge
Static Charge +
+
+
+
+
+
---
---
---
--
---
---
---
FPD Screens
Pellicles

4. 2024/1/3 ITRS Factory Integration TWG 4
Forces on a Contaminant Particle
Near Charged Surfaces
F
q q
r
 1 2
4 0
2

for 1000 V surfaces, the
greatest force is electrostatic!
gravitational
aerodynamic
Electrostatic

5. 2024/1/3 ITRS Factory Integration TWG 5
Electrostatic Attraction
200mm vs. 300mm
Particle deposition 3-6 times higher for wafers at 10kV
Particle deposition 30-60% greater at 300mm than 200mm
positive neutral negative
0.000
0.005
0.010
0.015
0.020
0.025
0.030
Rate
of
Contaminating
(/cm
2
-hr)
300 mm
200 mm
Polarity Dependence of ESA at One Fab

6. 2024/1/3 ITRS Factory Integration TWG 6
Destruction of Silicon Due to ESD

7. 2024/1/3 ITRS Factory Integration TWG 7
Device ESD Failure Mechanisms
 Human Body Model
 human contact with a sensitive device
 Machine Model
 charged conductor contacting a sensitive device
 Charged Device Model
 device contacts ground when in an electric field
 device package is charged and device contacts ground

8. 2024/1/3 ITRS Factory Integration TWG 8
1.5 m
ESD Effects on Semiconductor Manufacturing
Photomask Damage Due to ESD

9. 2024/1/3 ITRS Factory Integration TWG 9
ESD Events Create
Electromagnetic Interference (EMI)
ESD Radiates Radio Waves
and induces signals in
microprocessors and metrology tools
• Scrambled Program
Instructions
• Scrambled Data
• Confusing Error
Messages
• Microprocessor Lockup
• Calibration Failures
• Apparent Software Bugs

10. 2024/1/3 ITRS Factory Integration TWG 10
EMI Events in Photo
Ratio - 30:1

11. 2024/1/3 ITRS Factory Integration TWG 11
SEMI E78-0998 Electrostatic
Compatibility:
Guide to Assess and Control
Electrostatic Discharge (ESD)
and Electrostatic Attraction
(ESA) for Equipment
Semiconductor Equipment and
Materials International (SEMI)
E78-0998

12. 2024/1/3 ITRS Factory Integration TWG 12
SEMI E78-0998 Guide
Recommended Sensitivity Levels
ESD Control
(nC)
Contamination &
(Volts/cm)
Equipment
Malfunction
(nC)
Level 4 100 4000 1200
Level 3 50 400 600
Level 2 10 200 300
Level 1 1 100 150
Electric Field

13. 2024/1/3 ITRS Factory Integration TWG 13
Conclusions
 Major elements of technology change are smaller device
geometry, lower defect densities, larger wafers, faster
equipment operating speeds, and more dependence on
automation. All of these areas are adversely affected by the
presence of static charge in the semiconductor factory.
 Static charge needs to be controlled before it becomes a
barrier to new technology introduction, slows the ramping of
new factories, or a costly learning experience.
 SEMI Standards is working to extend the measurement
methods and levels of E78-0998 to the factory as a whole.
 The technology requirements in the ITRS will solve the static
problem in factory construction and in equipment design -
before static charge can impact production.