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 ionizationmodel. 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, aciddiffusion range, and polymerization length on LER are investigated through simulation. It is found that the relation of LER to photoresistpolymerization length is greatly affected by the photoacid concentration and diffusion range.