2. Presentation Outline Introduction to Chapman Instruments
MPT1000 Specification
Thickness Measurement Principle
Multi-Material Example (Glass and Silicon)
Bump Wafer Example
Reproducibility
Thickness Example Data
Bow and Warp Data Example
Roughness and Edge Chip Detection
Conclusions

3. Then, Now, Future
Supporting the Semiconductor industry for over 20 years
Over 180 Chapman Instruments surface profiling instruments installed world wide
Shipped first production thickness measurement system to a top ten IC manufacturer in September 2008

4. Product Offerings MPT1000 Wafer Thickness Measurement System
Wafer Bow and Warp
Surface Roughness
MPS Surface and Edge Profiler
Waviness
Roll Off
MP2100 High Resolution Profiler
Die Crack
Edge Chip
MP2200 High Resolution Profiler for Disk Media

5. Current World Wide Installed Base
Semiconductor Industry:
Texas Instruments ST Microelectronics ShinEtsu (S.E.H.) Philips Komatsu Sumco
STATS-ChipPac Unisem Siltronic
Amkor LG Siltron Hitachi
Disco MEMC Toshiba Ceramics
PTI
Disk Media:
Fujitsu Fuji Trace
Kaifa Showa Denko
Other:
Kodak Xerox Tinsley
Universities Optics Manufacturers
Over 180 Systems Installed

6. MPT1000 Manual Wafer Thickness Measurement System
Comprehensive Non-contact Measurement System
Thickness
Total Thickness Variation
Bow
Warp
Surface Roughness*
Edge Chip and Crack*
Tape Thickness
*Available with Automated Stage

7. MPT1000 Specifications Thickness Resolution < 0.1µm
Repeatability µm
Accuracy µm
Range µm-10 mm
Wafer Size Up to 300 mm
Safety Semi S2/S8

8. Measurement Optical Module
Laser based non-contact
Single or Dual focused laser beams
1 µm spot size
High resolution detectors
CDRH Class 1

9. Measurement Optical Module
Laser based non-contact
Single or Dual focused laser beams
1 µm spot size
High resolution detectors
CDRH Class 1

10. Detail of Measurement Principle

11. Measurement Technique
Objective
Focus Beam
Reflected Focus Beam Signal
The focus beam reflects from both top and bottom surfaces of the wafer as Infrared light is penetrated through the Silicon.

12. Dual Optical Head Flexibility
Scans can be set up to measure with just the Upper Optical Head…
With just the Lower Optical Head…

13. Dual Optical Head Flexibility
Or with Both Optical Heads.

14. Dual Optical Head Flexibility
Dual head is used to measure both Tape and Silicon Thicknesses.

15. Tape Measurement Technique
Both focus beams reflect from the top and bottom of the tape, providing a thickness measurement independent of the index of refraction.
The focus beam reflects from both top and bottom surfaces of the wafer as Infrared light is penetrated through the Silicon.

16. Glass Thickness Measurement
The focus beam reflects from the top and bottom of the glass surfaces as Infrared light penetrates through the glass.

17. Dual Optical Head Flexibility
Total and each layer thickness can be measured on a wafer composed of Silicon / Glue / Glass.

18. Multi Material Thickness Measurements

19. Multi Layer Wafer Thickness Data
Silicon TTV = 2.86 µm
Glass TTV = 0.73 µm

20. Dual Optical Head Flexibility
1 µm spot allows measurement of Si thickness between bumps on wafer.

21. Dual Optical Head Flexibility
Scan can be made right over the bumps to determined the bump heights.

22. Viewing System Example
Viewing system example showing the location of pads (1.25mm height by 0.92mm width). The marker shows the position of the measurement.

23. Automatic Find Bump Location
The MPT1000 automatically finds the center location of bump before a measurement as shown in the attached picture.
This image can also be automatically saved with the thickness data.
A thickness measurement can then be obtained at the bump center or on the wafer surface between two bumps.

24. System Tests for Measurement Confidence
Test Configurations
Repeatability Measurement at the Same Location
Gauge R&R
Pattern confirmation after Rotation
Linearity Tests

25. Reproducibility Tests for Individual Locations of 200mm Silicon Wafer

26. Linearity Thickness Tests

27. Rotate (90 Degrees) and Repeat (9 Data Points) for Feature Comparison
Mean Thickness = µm
Mean Thickness = µm

28. Thickness Measurement Reports
Bumped Wafer

29. Thickness Measurement Reports

30. Bow Measurement Report
Glass and Si

31. Warp Measurement Report
Glass and Si

32. Roughness Measurement Module
Laser based non-contact
Roughness and waviness data from single scan
Height Resolution < nm
Lateral Resolution 0.5 µm
Surface Type Si, Glass, etc
Roughness Parameters Rq (RMS), Ra, and Rpm (peak) and Rvm (valley)
Roughness Measurement Scan

33. Roughness Measurement Module
Laser based non-contact
Roughness and waviness data from single scan
Height Resolution < nm
Lateral Resolution 0.5 µm
Surface Type Si, Glass, etc
Roughness Parameters Rq (RMS), Ra, and Rpm (peak) and Rvm (valley)
Other systems lose resolutions as scan length increases. Some small features are undetected.
Chapman roughness system maintains height and lateral resolutions to detect smallest surface features.
Linear Roughness Measurement Scan

34. Sub-Angstrom Height Resolution
This 5 mm scan of a super-smooth polished silicon optical flat shows a roughness average of 0.4Å (250µm cutoff filter).

35. Roughness Control After Backgrind
Roughness Issue
Roughness control is important to minimize cracks
Optimizing roughness for metalization
Wafer Bow larger for higher stress and roughness
Roughness peak and valley data maybe related to wafer crack potential
300 mm Backgrind Wafer
Rq Roughness 2D Contour Plot

36. Fixed Area Optical Measurement Systems

37. Wafer Backgrind Pattern- 50mm x 50mm

38. Wafer Edge Crack and Chip Detection
1.0 mm
Wafer Edge
Edge Chip
Laser Spot
Damage to Wafers after Backgrind or Dicing Includes chips at the edge
Chips at the edge may damage die
Possible generation of a crack
Non-Contact System Automatically Detects and Locates chip damage
Circular Measurement 360 degrees at wafer edge
In-Line Microscope included for Visual Observation
Notch Finder and multiple edge chip location

39. Conclusions
Non-Contact providing several measurements in a single system
Wafer thickness
Total thickness Variation
Tape Thickness
Bump Height
via Depth
Bow and Warp Measurements
Roughness Measurements
Thickness resolution (0.1um) providing uniform TTV for production control of wafers
Measurements after back grind or dicing provides flexibility for thickness uniformity control
Small focused laser spot (1 um) provides the resolution required for measuring bumped wafers and via features

40. Die Crack on Wafers
Die Crack Detection by Slope Measurement (sensitive to small cracks)
Circular 360 degree or linear measurement pattern provides die crack detection near or at die locations
Detection of die crack on front or back of wafer
Detection of die crack capability through tape
Die Crack Discrimination
Measurement discrimination from particles and other surface defects
Die Crack Issue
Macro Crack potential to break wafer
Micro Crack potential to destroy individual die
Crack problem from backgrinding or dicing

41. Die Crack Examples and Video Pictures
Die Crack Analysis Data Shown from a Section of Circular Scan Measurement
Five die crack locations Identified from the data
Nomarski Video Images show Die Crack at the same locations as Data from MP2100
Difficult to observe cracks in the same direction as backgrind pattern with Nomarski Image
Chapman Measurement can detect cracks in the same direction as backgrind pattern

42. Die Crack Nomarski View- E

43. Die Crack Nomarski View- D

44. Die Crack Nomarski View- C

45. Die Crack Nomarski View- B

46. Die Crack Nomarski View- A

47. Die Crack Inspection DataB C E D
Scratch
Scratch
A – E: Die Crack Location

48. Damage at the Edge for Thin Wafers
Damage to Wafers after Backgrind or Dicing Includes chips at the edge
Chapman Non-Destructive System Automatically Detects and Locates chip damage
Circular Measurement 360 degrees at wafer edge
Fast Measurement
In-Line Microscope included for Visual Observation
Wafer Chip Issue
Chips at the edge may damage die
Possible generation of a crack

49. Circular Scan Geometry Near Wafer Edge

50. Microscopic View of Chips at Wafer Edge
Laser Spot
Edge Chip
Wafer Edge
1.0 mm

51. Measurement of Chips near Wafer Edge Circular Scan 50 µm from edge
Edge Chips

52. THANK YOU! Chapman Instruments 3 Townline Circle Rochester, NY 14623
Phone: (585)
Fax: (585)
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