Optimization for the measurement parameters of CD SEM for several specific situations

Different measurement parameter settings of CD-measuring scanning electron microscope (CD-SEM) can lead to deviations for identical patterns, especially for photoresist patterns with shrinkage effect. This deviation could not be neglected in the 28 nm and sub-28 nm processes. In this paper, we have studied the following cases: 1) Shrinkage effect of negative tone developing process photoresist; 2) Measurement parameter setting optimization for negative tone developing photoresist 1D&2D patterns; 3) Verification on FEM wafers.