Manufacturing processes

1. MIT OpenCourseWare
http://ocw.mit.edu
2.830J / 6.780J / ESD.63J Control of Manufacturing Processes (SMA 6303)
Spring 2008
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2. Control of Manufacturing
Processes
Subject 2.830/6.780/ESD.63
Spring 2008
Lecture #2
Semiconductor Process Variation
February 7, 2008
Manufacturing 1

3. Agenda
• The Semiconductor Fabrication Process
– Manufacturing process control
• Types of Variation in Microfabrication
– Defects vs. parametric variations
– Temporal variations: wafer to wafer (run to run)
– Spatial variations: wafer, chip, and feature level
• Preview of manufacturing control techniques
– Statistical detection/analysis of variations
– Characterization/modeling of processes & variation
– Process optimization & robust design
– Feedback control of process variation
Manufacturing 2

4. Semiconductor Fabrication Process, Part 1
R. J. Shutz, in “Statistical Case Studies for Industrial Process Improvement,” pp. 470-471, SIAM, 1997.
Manufacturing
Courtesy of the Society for Industrial and Applied Mathematics. Used with permission.
3

5. Semiconductor Fabrication Process, Part 2
R. J. Shutz, in “Statistical Case Studies for Industrial Process Improvement,” pp. 470-471, SIAM, 1997.
Manufacturing
Courtesy of the Society for Industrial and Applied Mathematics. Used with permission.
4

6. Semiconductor Fabrication Process, Part 3
R. J. Shutz, in “Statistical Case Studies for Industrial Process Improvement,” pp. 470-471, SIAM, 1997.
Manufacturing
Courtesy of the Society for Industrial and Applied Mathematics. Used with permission.
5

7. Semiconductor Fabrication Process, Part 4
R. J. Shutz, in “Statistical Case Studies for Industrial Process Improvement,” pp. 470-471, SIAM, 1997.
Manufacturing
Courtesy of the Society for Industrial and Applied Mathematics. Used with permission.
6

8. (Semiconductor) Manufacturing
Process Control
Image removed due to copyright restrictions. Please see Fig.
26 in Boning, D. S., et al. “A General Semiconductor
Process Modeling Framework.” IEEE Transactions on
Semiconductor Manufacturing 5 (November 1992): 266-280.
Manufacturing 7

9. Agenda
• The Semiconductor Fabrication Process
– Manufacturing process control
• Types of Variation in Microfabrication
– Defects vs. parametric variations
– Temporal variations: wafer to wafer (run to run)
– Spatial variations: wafer, chip, and feature level
• Preview of manufacturing control techniques
– Statistical detection/analysis of variations
– Characterization/modeling of processes & variation
– Process optimization & robust design
– Feedback control of process variation
Manufacturing 8

10. Defect vs. Parametric Variation
Manufacturing 9

11. Yield & Variation from Defects
• Electrical test
– measure shorts in test
structures for different spacings
between patterned lines (at or
near the “design rule” or DR
feature size)
– measure opens in other test
structures
Images removed due to copyright restrictions. Please see: Hess, Christopher. "Test Structures for Circuit Yield Assessment
and Modeling." IEEE International Symposium on Quality Electronics Design, 2003.
Manufacturing
Hess, ISQED 2003 Tutorial
10

12. Manufacturing 11

13. Manufacturing 12

14. Temporal Variation
Manufacturing 13

15. Manufacturing 14

16. Manufacturing 15

17. Spatial Variation
• Wafer scale
• Chip scale
• Feature scale
Manufacturing 16

18. Manufacturing 17

19. Manufacturing 18

20. Manufacturing 19

21. Manufacturing 20

22. Manufacturing 21

23. Manufacturing 22

24. Manufacturing 23

25. Manufacturing 24

26. Manufacturing 25

27. Manufacturing 26

28. Manufacturing 27

29. Modeling of Processes
and Variation
• Empirical modeling
• Physical modeling
Manufacturing 28

30. Manufacturing 29

31. Manufacturing 30

32. Manufacturing 31

33. Manufacturing 32

34. Manufacturing 33

35. Manufacturing 34

36. Manufacturing 35

37. Manufacturing 36

38. Manufacturing 37

39. Manufacturing 38

40. Manufacturing 39

41. Process Optimization &
Robust Design
Manufacturing 40

42. Manufacturing 41

43. Image removed due to copyright restrictions. Please see Fig. 7 in
Lakshminarayanan, S., et al. “Design Rule Methodology to Improve the
Manufacturability of the Copper CMP Process.” Proceedings of the IEEE
International Interconnect Technology Conference (2002): 99-101.
Manufacturing 42

44. Feedback Control of Variation
Manufacturing 43

45. The General Process Control Problem
Desired
Product Product
CONTROLLER
CONTROLLER EQUIPMENT MATERIAL
Equipment loop
Material loop
Process output loop
Control of Equipment: Control of Material Control of Product:
Forces, Strains Geometry
Velocities Stresses and
Temperatures, ... Temperatures, Properties
Pressures, ...
Manufacturing 44

46. Manufacturing 45

47. Manufacturing 46

48. Manufacturing 47

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50. Manufacturing 49

51. Manufacturing 50

52. Manufacturing 51

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55. Manufacturing 54

56. Summary
• The Semiconductor Fabrication Process
– Manufacturing process control
• Types of Variation in Microfabrication
– Defects vs. parametric variations
– Temporal variations: wafer to wafer (run to run)
– Spatial variations: wafer, chip, and feature level
• Preview of manufacturing control techniques
– Statistical detection/analysis of variations
– Characterization/modeling of processes & variation
– Process optimization & robust design
– Feedback control of process variation
Manufacturing 55