Stochastic simulation of photoresist line-edge roughness (LER) is attempted using a three dimensional (3D) lithography simulator incorporating a fast dissolution algorithm based on a modified critical ionization model. The fast 3D simulation permits detailed evaluation of the material and process effects on LER. In this article the effects of deprotection fraction, critical ionization fraction, photoacid generator concentration, acid diffusion range, and polymerization length on LER are investigated through simulation. It is found that the relation of LER to photoresist polymerization length is greatly affected by the photoacid concentration and diffusion range. (c) 2005 American Vacuum Society.