Using CD SEM to evaluate material compatibility with DUV photoresists

摘要

A nondestructive test procedure provides quantitative data on control and test wafer linewidths in the lithography cell. The adverse effect of airborne molecular contaminants, such as ammonia or various amine compounds, on the control of critical dimensions (CDs) during lithography of sub-0.5-μm linewidths is well understood in the semiconductor industry. As device dimensions continue to shrink, this phenomenon and its effects on defect density and product yield have become an increasingly important concern. In response, both manufacturers and users of photolithography equipment must implement procedures that will help ensure that the process chamber remains free of molecular contamination. Because of the need to review the potential of all materials in the processing area to contribute airborne contaminants, the amount of required testing can be significant.