A study of Cr to Mosi in-situ dry etching process to reduce plasma induced defect

Abstract

Dry etching process is widely used in semiconductor field and in photomask manufacturing. Even though dry etching technique can be much better in obtaining straight profile and better CD (Critical Dimension) uniformity than wet etching technique, it has a severe problem in terms of defect issue. Especially, very tough controllability of defects is essential for the photomask dry etching process because defect can be printed on the wafer over. Therefore, we studied defect free photomask etching techniques and found out the possibility of particle evasion. With In-situ etching method, defect generation by MoSiON etching could be reduced compared to when standard etching process is used while the process result is almost same as that of the standard process. In this paper, we will present the experimental result of in-situ. dry etching process technique for Cr and MoSiON, which reduces the defect level significantly.