Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single...
Transcript of Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single...
![Page 1: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/1.jpg)
Greener SC1 Process For Single Wafer CleansDhiman Bhattacharyya, Ph.D.GLOBALFOUNDRIES
400 Stonebreak Rd. Ext., Malta, NY - 12020
Mobile: 518-948-3123
Email: [email protected]
April 10, 2018
![Page 2: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/2.jpg)
2
Background
• Standard Clean-1 (SC1), also known as RCA-1 clean and APM (ammonia peroxide
mixture), is extensively used as one of the major components of the semiconductor
wet cleans processes.
• It is a mixture of ammonium hydroxide and hydrogen peroxide in deionized water.
The ratio of the two chemicals may vary for different processes.
• Due to high volume usage of SC1, majority of the waste going down through IWD
(industrial waste drain) consists of this alkaline solution.
• Requires pretreatment to an acceptable condition for discharge to the sewers.
• Requires control over the quantities and rates of discharge.
![Page 3: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/3.jpg)
3
Background
• SC1 flow rate also varies by tool configuration, vendors and finally by
process windows.
• Usual flow rates range from 1000 ml/min to 2500 ml/min
• Reduction in the SC1 flow rate helps in multiple ways:
1. Reduces chemical consumption and associated chemical cost,
2. Reduces SC1 waste volume and associated cost to neutralize the waste.
• Reduction in the SC1 flow rate risks the wafers in multiple ways as well:
1. Possible more particles
2. Lower etch rate
3. Within wafer uniformity
4. Finally, lower yield
![Page 4: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/4.jpg)
4
Background• Considering following assumptions, calculations show that reduction in SC1 flow
rate reduces the effective process cost significantly.
Assumptions:
• SC1 ratio 1:1:50 (NH4OH:H2O2:H2O)
• SC1 Flow time: 1 min
• Total process steps using 1 min SC1 = 40
• Moves @ each of 40 process steps = 100k
![Page 5: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/5.jpg)
5
Approach
• Evaluated the effect of SC1 flow rates on etch rate on blanket wafer
• Evaluated the surface particle adders from various SC1 flow rates
• Compared the PRE (particle removal efficiency) on product wafer
• Compared the inline thickness on product
• Compared sort yield between low and high SC1 flow rates
![Page 6: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/6.jpg)
6
Etch rate on blanket wafer
• A minor difference in thickness etched and sigma were observed among
various SC1 flow rates for SC1 only process.
![Page 7: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/7.jpg)
7
Particle Performance on blanket wafer
• No significant difference in particle performance was observed among
various SC1 flow rates for SC1 only process.
![Page 8: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/8.jpg)
8
Particle Performance on blanket wafer
• No significant difference in particle performance was observed among
various SC1 flow rates for SPM-SC1 only process.
![Page 9: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/9.jpg)
9
Particle Performance on blanket wafer
• No significant difference in particle performance was observed among
various SC1 flow rates for SPM-SC1-SC1NS only process.
![Page 10: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/10.jpg)
10
Particle Trend on Product
• Process with low SC1 flow rate showed
comparable to or better than the process
with high SC1 flow rate in particle
performance.
![Page 11: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/11.jpg)
11
Inline Trend on Product
• Process with low SC1 flow rate showed comparable data to the process with
high SC1 flow rate.
![Page 12: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/12.jpg)
12
Yield Analysis on product
• Process with low SC1 flow rate showed comparable to or
better than the process with high SC1 flow rate for both Ship
Yield and Prime Yield.
![Page 13: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/13.jpg)
13
Summary
• Reduced SC1 usage means reduction in industrial waste volume and pre-
treatment cost.
• Reduction in SC1 flow rate also reduce the process cost.
• A comprehensive study was conducted to evaluate the effect of various
flow rates of SC1 on process.
• An optimized process with reduced SC1 flow rate was evaluated on
product showing no degradation defects or in sort yield.
• Encourages tool vendors to work on BKMs with reduced chemical usage.
![Page 14: Greener SC1 Process For Single Wafer Cleans€¦ · 03/04/2018 · Greener SC1 Process For Single Wafer Cleans Dhiman Bhattacharyya, Ph.D. GLOBALFOUNDRIES 400 Stonebreak Rd. Ext.,](https://reader035.fdocuments.net/reader035/viewer/2022081514/5fbbebd81d0432329238b9dd/html5/thumbnails/14.jpg)
Acknowledgment:
All colleagues in GLOBALFOUNDRIES
14