As design rule of devices are getting smaller, it is hard to obtain enough process window like DOF, EL. In aspect of
device integration, lithography processes which are included in etching process became more and more important. It has
been claimed that photo resist profile is closely related with etch bias and vertical profile. Resist top-loss and bottom
slope seriously affect after-etching profile. In order to address these problems, new model based verification method is
necessary for preventing hot spots.
In this paper, we propose more practical method of model based verification using rigorous simulation and wafer
verification results. Highly accurate model is obtained by physical model fitting with minimal experimental data set.
After that, virtual data are extracted from rigorous simulation model for applying full chip model based verification
modeling. Basically, 2 data sets will be needed for verification of 2-level model, for detecting resist top-loss and bottom-slope.
Finally this article shows comparison results of model based verification and real wafer inspection. And also, we
try to prove that the newly proposed method is another good candidate to address existing problems such as pinching and
bridging after post etching and CMP process.