关键词: 相移掩模, 条宽偏差, 条宽偏差控制, 干法蚀刻

Abstract: In this paper, the method for achieving precise CD MTT (critical dimension mean to target) of PSM (phase shift mask) was investigated. In the manufacturing process of PSM, there are several factors influencing the CD MTT results. Variation of blank material condition, variety of patterns and instability of patterning processallhave impacts on CD MTT. In order to correct CD MTT error, Cr CD after removing resist was measured before MoSiN dry etching, and addition corrective Cr etching time based on Cr CD was applied to modify CD error. The relationship between CD shift and corrective Cr etching time for masks with various pattern densities was also studied. As a result, accurate CD control and significantmodification of CD MTT error for PSM was achieved byuse of the CD correction method investigated in the paper.

Key words: phase shift mask (PSM), CD MTT, CD correction, dry etching