Effects of resist sidewall morphology on line-edge roughness reduction and transfer during etching: is the resist sidewall after development isotropic or anisotropic?

摘要

Measurements of the sidewallmorphology of commercial resistnlines (3-D line-edge roughness) after lithography and before etching byncritical dimension atomic force microscopy (CD-AFM) and scanning elec-ntron microscopy show that they exhibit anisotropy in the form of striationsnperpendicular to line direction. When this anisotropy of postlithographynresist sidewalls is included in the models for trimming and pattern trans-nfer proposed in an earlier paper [Constantoudis et al., J. Micro/Nanolith.nMEMS MOEMS 8(4), 043004 (2009)], the models predict the beneficialnrole of trimming process in line-edge roughness reduction during patternntransfer, in agreement with experimental results. Furthermore, experi-nmental and simulation studies show that the CD-AFM measurements ofnthe 3-D line width roughness may overestimate the correlation length.nTaking into account this finding in the model for trimming, we find thatnmodel predictions further approach the experimental results