Using rinse resistivity to reduce UPW usage

Summary form only given. Water conservation efforts in the semiconductor industry have been categorized by SEMATECH into three main areas: reduction, reclaim, and recycle (Chen et al, 1997). Reduction includes not only improving the efficiency of existing tools and processes, but also developing replacement tools and processes which use less water. Reclaim is defined as reusing waste water in a different process from where it was originally used (e.g. fab rinse effluent used in air scrubbers). Recycle is defined as reusing waste water in the same process from which it came (e.g. fab rinse effluent returned to the UPW plant). This project focuses on Motorola´s Advanced Products Research and Development Laboratory´s (APRDL) recent wet tool UPW usage reduction efforts using rinse resistivity during process conditions. A study was undertaken to investigate UPW usage reduction in wet tools via optimization of rinse processes. This study included: collection of rinse resistivity data for 15 chemical/rinse tank combinations with various wafer surfaces and chemical bath lifetimes in order to baseline the efficiency of APRDL´s current process rinses; devising a strategy for optimizing overflow dump rinse processes; collection of confirmation resistivity data for five rinse test recipes