Sowmya Krishnan & Mohamed Saleem, Ultra Clean Technology, Menlo Park, CA, USA

ABSTRACT

Gas delivery systems transporting corrosive and reactive gases could potentially compromise the purity of the gases. Currently, gas delivery tubing and components are made of electropolished (EP) stainless steel. Welds and heat-affected zones of EP stainless steel undergo severe corrosion when halogen-based gases are transported. Chromium-rich oxide passivation (CrP) of stainless steel can successfully counter these corrosive effects. Two case studies comparing EP and CrP stainless steel are presented. Additionally, an analysis is presented of cost-of-ownership issues associated with CrP systems.