E4 NM Water Conservation Alliance Roundtable Discussion Reducing Water Usage in Semiconductor Manufacturing March 23, 2000 Rio Rancho,NM

E4 Experience with a Recycle DI System Kurt Eckert EEEE 951 Amsterdam Dr. Colorado Springs, CO

E4 Contributors u System design - Jacobs Engineering u Manufacturer - Glegg Water u Atmel Project Manager - Kurt Eckert

E4 Objective u What is DI recycle vs. DI reclaim? u Why is DI recycling necessary? u Why was this recycle system installed? u What are the hurdles for a recycle system? u Review the system design u Share actual operating experience

E4 A recycle system u Collects a portion of the drains from process tools and reprocesses it back to a quality to be: u Reintroduced back at some point in the primary UPW system u Reutilized for a lower quality DI system such as CMP or central clean

E4 A Reclaim System u Collects a portion of the drains from process tools and may or may not reprocess it back to a quality to be: u Used in other applications such as: u boilers u cooling towers u scrubber make up u irrigation

E4 Recycle/reclaim graphically Primary UPW System Fab UPW Utilization Fab Drains RecycleReclaim Make-up water Boilers, Scrubbers, Cooling Towers Evaporation WWT

E4 Why is recycling necessary u Sematech (1995)- 2,275 gallons of water to process one 6 inch (150 mm) wafer u Semiconductor Industry (1996)- 8 wafers increase water consumption by 250%, over 6 wafers u Cleanrooms (1996)- Projects 7X increase in UPW consumption for 300mm wafers over 200mm wafers

E4 Why was this recycle system installed u Fab expansion required more UPW capacity u WWT system did not have any capacity margin u City sewer line was at capacity u Lower first cost

E4 Major hurdles u Fear (paranoia) about contamination of DI system (TOCs) u Financial, payback u Notion that water resources are without limit u Space

E4 Design considerations for this system u Collect water only from the best sources. No solvent hoods. u Monitor TOCs early in collection system with ability to dump on high TOCs u Install a system to remove TOCs

E4 Design considerations for system (cont.) u Monitor TOCs in final product with ability to dump before introducing into the UPW system

Recirc tank Transfer tank Analysis tank Schematic of Recycle system Analysis tank WWT Drains msms High Low TOC HighLow sodium hydroxide Hydrogen Peroxide City water backup sodium hydroxide sodium bisulfite WWT 185 hm TOC Destruct UV filter.1mm CMP Quartz Clean WWT Recycle to RO storage tanks UPW system TOCs Electro- Deionization Low Manual Valve Reuse boilers, scrubbers Advanced Oxidative Process RO filter 1mm Cooling Heat Exchanger

Actual Operating Data (TOCs) Analyzer A TOCs ppb Recycle TOCs 0-50 ppb Analyzer B TOCs ppb

Actual Operating Data (conductivity) Drain Conductivity mS Recycle resistivity 0-20 mW Drain Flow GPM

E4 Operating Experience u Need to work with Line Maintenance and Production personnel u Explain what the system does and how solvents impact the system u Label each piece of equipment u Repeat every 6 months u Also, need to work hand in hand with operators

E4 Operating Experience (Cont.) u There was a significant reduction in primary regenerations saving: u manpower u chemicals u water u CEDI is not ready for polishing loop applications

E4 Final Thoughts u The skeptics watch you closer and expect more of you when you have a recycle system u People are amazed at how much water (read $$$) are saved u The experience has been: u Scary u rewarding u Frustrating u exhilarating