Good OPC where will this drive mask CD tolerance and mask grid size

摘要

Abstract: At low k$-1$/ factors, optical proximity correction (OPC) is used to correct line size such that what is delivered by the lithography process is closer to the design dimension than an uncorrected process would deliver. OPC is usually derived for perfect masks and exposures. Random variation of the mask critical dimension (CD), wafer exposure latitude, and wafer defocus are examined for their effects on an OPC mask. Expected CD variation in the aerial image is given for each of these variables. Examining these variables will also give insight as to how fine an OPC can realistically be obtained, and how fine a grid size is needed in the manufacture of the mask. !3