Brian Raley & Chris Nauert, Motorola, Austin, Texas, USA
ABSTRACT
With the recent economic downturn in the semiconductor industry, methods to reduce expenses and lower the break-even point have grown in importance. Cost reduction efforts that can be implemented with little to no expense are, and will continue to be, the preferred mechanism for cost reduction. Cost reductions from water conservation are sometimes overlooked, but can provide annual cost savings in addition to resource conservation. With the industry moving to a larger wafer size, increased ultrapure water (UPW) purity requirements and an increase in process steps, there is a potential for UPW consumption and the associated costs to increase if conservation measures are not implemented. Motorola has investigated numerous cost reduction efforts from water conservation at several different sites. This paper will discuss some of the recently implemented and relatively simple water use reduction activities including flow standardization across tools (in CMP, fab support equipment and wet cleans) as well as wait-time flow reduction, RCA clean rinse reduction, and installation of restrictive flow orifices in CMP slurry lines.