Investigation of shot noise induced line-edge roughness by continuous model based simulation

摘要

A new strategy for LER simulation is proposed in this paper, which applies a discrete model at 1～2nm scale for exposure, continuous reaction-diffusion model at 7nm scale for post-exposure bake (PEB) and a newly developed continuous statistical lateral dissolution model (SLDM) at 1 nm scale for development. Without the computational complexity of a molecular LER simulator, this new LER modeling is able to simulate LER induced by exposure statistics by incorporating impacts of PEB and dissolution. This LER simulator has been used to investigate factors that impact LER generation, including non-Fickean diffusion, shot noise and resist contrast. SLDM has also been applied to analyze large unlikely roughness event (LURE) that can lead to chip failure. By finding an equivalent lateral dissolution path for LURE, an analytical estimation of LURE is obtained.