Study of photo resist-free process for shallow trench isolation etch on advance VLSI technology

摘要

The photo resist (PR) tilting defects and bridge defect occurred for shallow trench isolation etch with PR free process on high density plasma etch chamber TCP9400 were studied. First, serious PR tilting defects induced by 193 nm PR charging effect during the etching process was noted in our study. Through the L9 experiment data, a new etch recipe which optimizes the source power, pressure and etch gas chemistry was studied to solve this problem. Results showed that the new approach can not only eliminated defect, but also improve device enhanced effective channel (Weff) and Cp yield. The bridge defect was recovered by optimizing PR in situ strip procedure. The defect count can significantly reduced to 75% of its original level.