Mask aligner lithography simulation – From lithography simulation to process validation

Abstract

Based on the comparison between simulated and experimental results, we investigate the predictive qualities of mask aligner lithography simulation. Using a properly calibrated photoresist development model, it is possible to predict photoresist profiles with good quantitative accuracy. Dissolution rate monitors are shown to be an excellent tool to calibrate the development models for many of the photoresists typically used in mask aligner lithography. The accurate description of the photoresist in the simulations closes the gap between process control in the clean room (which is based on the evaluation of photoresist profiles) and recent efforts to use numerical methods to optimize the optical parameters of the lithography process.