Optimization of 28nm HK/MG single wafer cleaning process

Wet chemical processes are used in a variety of integrated circuit (IC) fabrication processing steps, also single wafer wet processing tools have become part of the critical tool-set in advanced IC manufacturing. How to clean trench bottom efficiently and effectively is a really challenging job for wet process. In this paper, we studied and found that multi clean steps are much better than single clean step process, while optimizing D.I scan range and N2 flow would further improve the performance. It works in 28nm HK/MG NMOS clean process.