Three-dimensional post-exposure modeling and its applications

摘要

A three-dimension post-exposure bake (PEB) simulator (STORM3D) is described with improved algorithms for effectively simulating chemically-amplified resists (CAR) on desktop computers. A new FEM algorithm that is based on variable elimination is presented and shown to reduce the simulation time by roughly a factor of four. A dramatic increase in the size of problems that can be treated with limited memory is demonstrated by the use of a frontal method. Results for latent images of the deprotection concentration are presented for T-topping and footing in the presence of pre-diffused contaminants in elbow patterns. A methodology is suggested for estimating diffusion parameters through simulation interpretation of the cross-shape profile from a sequential double exposure of orthogonal lines. The sensitivity of the methodology is illustrated through comparing corner shapes for UVIIHS and APEX-E. The improvements in STORM3D allow 9,000 node 3D problems to be simulated in about one hour for 60s PEB on a 700Mhz Dec-alpha with 256M memory.