Effects of model polymer chain architectures and molecular weight of conventional and chemically amplified photoresists on line-edge roughness. Stochastic simulations

In the pursuit for low line-edge roughness (LER) photoresists, molecular modeling can aid by pointing the way to the appropriate polymer chain architecture. Stochastic simulations of the whole lithographic process are performed from exposure throughout development of the patterns. The polymer chain architectures studied are the random walk, the randomly grafted chains and the linear chains. Dissolution was performed based on the concept of critical ionization and using a computationally fast dissolution algorithm. The combined effect of chain architecture, deprotection chemistry, and molecular weight on LER was investigated in a two-dimensional simulation framework and directions for reducing photoresist LER are suggested. It is seen that when conventional resists are assumed, linear chains exhibit higher LER than randomly grafted, while in the case of chemically amplified resists the reverse behavior is seen. (c) 2006 Elsevier B.V. All rights reserved.