Dr. Steve Allen and Dr. Michael R. Hahn, Microbar Incorporated, Sunnyvale, CA, USA

ABSTRACT 

Modern semiconductor fabs are highly dependent upon a continuous flow of ultra-pure water for normal operations. Large fabs measure their water usage in millions of gallons per day. The cost of producing this water, both in capital expenditures and community goodwill, is continually rising as world-wide fab capacity is expanded. Most of the current water consumption is for processes such as CMP, wet etch, wafer cleaning and back grind. The wide disparities in pH, dissolved and suspended solids content, and metallic contamination present major challenges for facilities trying to treat wastewater.