Dominance of inclusions over passivity in contamination release from the corrosion of stainless steels in advanced chip manufacturing

In the semiconductor manufacturing industry, controlling particulate release is crucial for wafer production yield. Stainless steel is widely used in the delivery of specialty gases, but corrosion is still a thorny problem. This study systematically compares the corrosion resistance of several typical stainless steels after mechanical grinding, mechanical polishing, and electropolishing in both aqueous and specialty gas environments, revealing significant differences in conclusions between aqueous environment and the simulated specialty gas environment. By examining the surface microstructure, the roles of topographical differences, passive layer, and inclusions are discussed. The corrosion rate in specialty gas environment shows a strong correlation with the population of inclusions, and the role of micro-crevices in corrosion under micro-droplets is discussed. It is concluded that, on a macroscopic level, the presence of inclusions dominates the corrosion characteristics of stainless steel in specialty gas environments.