1. Shadman 1 Water: A Key Process Fluid and an Environmental Bottleneck in Semiconductor Manufacturing Farhang Shadman University of Arizona  1999 Arizona Board of Regents for The University of Arizona NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

2. Shadman 2 Water Usage In Semiconductor Plants Shadman 148 Goal: Significant reduction in water use for the next three years: 2-3 fold reduction in UPW usage per in 2 of Si for the 300 mm wafers. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

3. Shadman 3 WATER AND ENERGY TECHNOLOGY REQUIREMENTS 1997 250 nm 2000 180 nm 2003 130 nm 2006 100 nm 2009 70 nm 2012 50 nm Decrease net feed water use Gal/in 2 30106522 Decrease UPW use Gal/in 2 22107655 Lower water purification cost X90%X80%X70%X60%X50%X Decrease energy consumption KWh/in 2 987554 300MM energy consumption KWh/in 2 4443 Solutions Exist Solutions Being Pursued No Known Solutions

4. Shadman 4 Strategies to Achieve the UPW Goals Replace wet processes: –The environmental gain is not obvious or guaranteed Reduce water usage: –Emphasis on FEOL and rinse processes for FEOL and post- CMP Reuse and recycle NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

5. Shadman 5 Drivers for Water Conservation Strategies Improve process and products performance Lower cost Insure sustainability in operation and growth The three drivers are interdependent The three drivers are not contradictory Insuring sustainable growth is the primary environmental justification NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

6. Shadman 6 Recycle and Reuse Which one is preferred What are the determining factors? UPW PlantRinse Operation Cooling / Gas Scrubbing Feed Water NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

7. Shadman 7 Determining Factors: Purity at the POU Purification cost System & installation cost Real risk Perceived risk UPW Plant Rinse Operations Cooling/Scrubbing UPW Plant Rinse Operations Cooling/Scrubbing Reuse Recycle Match the flow rates for supply and demand (water balance) Match the water quality for supply and demand (optimization) Guidelines: NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

8. Shadman 8 (160 gpm) Humic Acid @ 3 ppm 270 gpm with recycle 430 gpm without recycle Recycle/Feed Ratio (R/F) Point of Use TOC Conc. (ppb) 04.1 0.303.6 0.602.1 NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Effect of Recycle on POU Purity

9. Shadman 9 Time Q * C Rinse A (Q A ) Rinse B (Q B ) Area A = Area B Rinse and Reuse Inter-dependence UPW Plant Rinse Operations Q NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing C

10. Shadman 10 (50) 500 UPW Plant Rinse 1000 (30) 500 (10) P 500 (100) 500 S (160) (50) 1000 (150) UPW Plant Rinse Present operation: (50) 200 (550) UPW PlantRinse Option 1: Reduce the rinse flow Option 2: Keep the rinse flow; add moderate recycle NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Rinse and Recycle Inter-dependence

11. Shadman 11 (50) 1000 (150) UPW Plant Rinse Present operation: Option 3: Keep the rinse flow; add aggressive recycle (50) 50 UPW Plant Rinse 1000 (10) 950 (~8) P 950 (~108) 50 S (150) NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Rinse and Recycle Inter-dependence

12. Shadman 12 (50) 50 500 (214) UPW Plant Rinse 500 (14) 450 (10) P 450 (~205) 50 S (300) Option 4: Decrease the rinse flow, combine with recycle (50) 1000 (150) UPW Plant Rinse Present operation: NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Rinse and Recycle Inter-dependence

13. Shadman 13 NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

14. Shadman 14 Adverse Effects of Concentrating the Recycled or Reused Wastewater Stream Lowering TOC removal efficiency Lowering ion exchange utilization factor Being out of range for some of the purification unit processes Triggering fouling mechanism –Biofouling and biofilm –Corrosion NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

15. Shadman 15 UPW Strategic Research Needs for 2003 and Beyond 1. Low water, high performance FEOL and post-CMP rinse 2. Low energy, robust purification processes 3. Advance waste segregation and collection 4. Simulator-based metrology and control 5. Matched supply and demand purity 6. Advanced design tools to facilitate low-cost, low risk, high performance preparation and distribution of UPW 7. Special UPW sub-system for CMP 8. On-line rapid-response multi-component sensors for 3,4,5,7 NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

16. Shadman 16 Issues and Technology Gaps Related to Water and Wastewater Purification Low-energy and low-chemical new purification processes Multi-component interactions of process-generated impurities Robust purification methods with tolerance to system upsets and transience Improved removal of recalcitrant compounds, particularly organic impurities NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

17. Shadman 17 NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

18. Shadman 18 Shadman p173 1997 250 nm / 200 mm 2003 130 nm / 300 mm 2006 100 nm / 300 mm 2009 70 nm / 450 mm 2012 50 nm / 450 mm 1999, 2001 180 nm / 300 mm 150 nm / 300 mm Recycle New Purification Metrology AdvancedControl Recycle Conservatio n Recycle Conservation Metrology 10 20 30 10 20 Net Feed ( gal / in 2 ) UPW Use ( gal / in 2 ) Year Technology Trends and Technology Gaps for Water Usage Strategic Solutions Research Gaps Tactical Solutions NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

19. Shadman 19 Feed Tank Pre- Treatment Primary Storage Tank Primary Treatment UPW Polishing Storage Tank Polishing Treatment FAB Process Tools SRW Storage Tank UPW Return UPW Supply Municipal Feed 2 nd RO Reject 1 st RO Reject UF Reject UPW System with Recycle Options Monitoring/ Purification Recycle Sensor/ Divertor Sensor/ Divertor IWW Reject NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

20. Shadman 20 Structure of the UPW Recycle Simulator NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Water Balance Model (Flow Balance Equations) Main Program: Simultaneous PDE’s for Species Balance Rinse Module Treatment Modules IEx UV AC Loop Solver Dynamic Link Parameter Database Flow Sheet Specifications - Impurity concentration (time and location) - Water balance Input Output User- Friendly Level Linkage Level Main Code Level RO

21. Shadman 21 NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Effect of Recycle on POU Impurity Concentration Polishing UV IEx S Secondary Treatment Reverse OsmosisUV/Ion Exchange Primary Treatment Point-Of-Use Feed Treatment Recycle Polishing Loop 20,000 10,000 (400 gpm) (700 gpm) (200 gpm) (130 gpm) (100 gpm) (40 gpm) (160 gpm) Humic Acid @ 3 ppm 270 gpm with recycle 430 gpm without recycle Calcium Sulfate

22. Shadman 22 Importance of Multi-Component Interactions A critical technology gap in approaching risk-free recycling. Potentials for chemical interactions caused by process- generated reactive compounds; formation of problematic impurities. Change in the efficiencies of purification processes. Re-entrainment of impurities due to multi-component effect. Effect on metrology and control. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

23. Shadman 23 Key Questions  What are the important impurities?  Which impurities are trouble makers in UPW systems with recycle?  How can we remove these harmful impurities?  How should we collect the waste water: mixed or segregated; diluted or concentrated?  What are the treatment options?  Given the above information, how do we design a recycle system, optimize it, or control its operation? Issues: effectiveness, cost and reliability. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

24. Shadman 24 Organic Impurities Problems: Proven detrimental effect on yield  Wide variety of impurities with different properties  Conversions and reactions  Recalcitrant impurities Removal Method: Separation by membranes and filters  Adsorption  Degasification  Chemical reactions (oxidation, decomposition) NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

25. Shadman 25 NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Experimental Setup for Adsorption Studies (Ion Exchange and Activated Carbon Application)

26. Shadman 26 U Z S = unoccupied site S i = solid phase impurity C i = fluid phase impurity Activated carbon particle Competitive adsorption Dispersion Convection Dynamics of Multicomponent Impurity Removal by Adsorption NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

27. Shadman 27 Secondary Contamination due to Desorption of IPA from Activated Carbon 0 100 200 300 400 500 600 700 800 900 050100150200250300350400450 Time (min) TOC (ppb) 15" column 9" column 6" column UPW Start 100 ml/min of 10 ppm HCl thru column Start 100 ml/min of UPW thru column Secondary Contamination NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

28. Shadman 28 Impurity Release due to Multicomponent Interactions (Adsorption on Activated Carbon) Fluid Phase Concentration (ppb) Time (min) Inlet Concentration for Component A 700 ppb Component A Multicomponent Component A Single Component Component B Multicomponent Component A only Both components A and B Net impurity release from the column NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

29. Shadman 29 6” Test column 9” Test Column 12” Test Column 15” Test Column Model Fit Model Deviation due to Fluid Retention in Pores Fluid Phase Concentration (ppb) Desorption of IPA from Activated Carbon Time (min) NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

30. Shadman 30 Start 150 ml/min of 150 ppb IPA thru column 6” Test column 9” Test Column 12” Test Column 15” Test Column Model Fit Adsorption of IPA on Activated Carbon Fluid Phase Concentration (ppb) Time (min) NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

31. Shadman 31 Water Softener AC Prefilter Ion Exchange RO Tank RO #1 Ion Exchange 10 gal Tank 100 Gal Tank 185 nm UV Degassifier Ion Exchange Ultra Filter Recycle Tank To Drain RO #2 Polish Loop Recycle Loop Primary Treatment Pre-Treatment Bypass Bench-Scale UPW Testbed Feed Pump NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

32. Shadman 32 HP Recycle System with IPA Carbon Bed Cation Exchange Anion Exchange 254 nm UV 3000 gal. Bypass Return RO Storage Tank Spent Rinse Water NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Concentration (ppb) Time (min) Data Model

33. Shadman 33 Trends and Technology Gap for Energy Usage Tactical Solutions Strategic Solutions Research Gap NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

34. Shadman 34 Organics Water UV Membrane Support Catalytic sites Flow-through configuration (oxidation and filtration) Tangential configuration (oxidation and degasification) Two Configurations Under Development NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

35. Shadman 35 Catalytic Membrane Experimental Setup UV Source Gas In Gas Out Quartz Window Reactive Membrane Support Catalytic Packing Water Tank NDIR CO/CO 2 MS Capillary Vacuum Chamber GC TOC Analyzer UV Multi-port Valve Purge gas NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

36. Shadman 36 Effect of Adsorption on Photocatalytic TOC Removal (Response to 30 ppb IPA in the feed) 0 5 10 15 20 25 30 010203040 Time (min) IPA Concentration (ppb) Non-catalytic Photocatalytic Adsorption Reaction NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing

37. Shadman 37 Catalytic Oxidation of IPA Initial IPA Concentration: 2.2 ppm NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing