1. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 1 CMP Water Recycling Dr. Russ Parker Hewlett Packard Laboratories Based on a system designed at the ULSI Fab, Palo Alto, CA  1999 Arizona Board of Regents for The University of Arizona

2. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 2 Why CMP? Why Recycle? CMP processing can use approximately 1/3 of all water consumed in a fab. The great majority of water from the area has virtually no contamination in it. Recycling is becoming a way of life. The main issue is how to implement recycle for maximum recovery and security.

3. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 3 Previous Recycling Spent Rinsewaters Carbon Bed Cation Exchange Anion Exchange 254 nm UV 30,000 uW Return RO Storage Tank 3000 gal. Fab 450 gal. TOC, Ohms Typical UPW System AWN ? TOC, Ohms ?

4. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 4 Operations with CMP Water Polishers (Strausbaugh) (3-6 gpm) Scrubber (0.5 gpm) Chemical Clean Rinses (15 gpm) Staging Tanks (5 gpm) Rinser/Dryers (4 gpm) No Recycle? Yes

5. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 5 What’s in the Water? Slurry (a few types) Ammonia (0.5 gram) Hydrogen peroxide (0.5 gram) Hydrochloric Acid (0.5 gram) Iron, Copper (ppm) Resist & Dielectric (ppm) Particles (?) Others in Trace Amounts

6. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 6 CMP Water Paths-- A Recycler’s View SC-1 Rinse SC-2 Rinse SRDSRD Polish Tables Staging SC-1 SC-2 Scrubber Chemistry and Rinses Fluoride and Metals Caking AWN Recycle System ? Parts Cleaning

7. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 7 Polisher Water Flow Receivin gTank Waste Drain Polishing table Spray Nozzles Sending Tank Receiving Tank Dog dish

8. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 8 Recycling with CMP Spent Rinsewaters Carbon Bed Cation Exchange Anion Exchange 254 nm UV 30,000 uW Return RO Storage Tank 3000 gal. Fab 450 gal. TOC, Ohms Typical UPW System AWN ? TOC, Ohms ? AWN

9. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 9 What Happens to CMP Recyclable Water? Ammonia - evaporation or cation resin Hydrogen peroxide - activated carbon Hydrochloric Acid - anion resin Iron, Copper - resin Resist & Dielectric - filters Particles - filters Others in Trace Amounts - resins Slurry - ?? The Recycle System treats CMP water containing:

10. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 10 Benefits of Loop Recycle vs. Local Returning to the house recycle system provides quality assurance. –6 ion exchange beds, 4 UV lamps, 3-4 filters Only one supply line and one collection line are needed. Purity is not a question because the quality is controlled by the house system. No new tanks, filters, or treatment Massive dilution avoids events, provides lots of reaction time Easy install - collection line and tie-in point as opposed to new equipment

11. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 11 Slurry Waste from CMP - Part 1 Is mixed with other site regulated wastes Contains silica, alumina, iron, hydrogen peroxide, potassium hydroxide, ammonium hydroxide, and other slurry mix items Contains copper, tungsten, aluminum, resist, dielectric Collects (somewhat) in a holding tank to an equilibrium level, then is transferred as it arrives

12. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 12 Slurry Waste from CMP - Part 2 Is collected in a vat Is mixed with metal rinses from the site Is mixed with CaCl2, caustic, floc Is allowed to settle Sludge goes to a caker Supernatant and squeeze-out go to resins Discharge liquid goes to Acid Waste Neutralization (AWN)

13. NSF/SRC Engineering Research Center for Environmentally Benign Semiconductor Manufacturing Parker 13 Summary The system results in almost all of the rinse/idle water in the CMP process being recycled (except for water directly from polishers due to heavy silica loading). Maximum water quality is assured because the recycled water goes to the RO product tank. The use of recycling results in the avoidance of some additional equipment scale-up to meet further UPW demands. Slurry waste is efficiently handled by an existing Metals/Fluoride caking system.