Full-Chip Lithography Verification for Multilayer Structure in Electron-Beam Lithography

Abstract

In this study, a simplified electron energy flux (SEEF) model for electron-beam (EB) lithography has been evaluated by comparing it with the Monte Carlo (MC) simulation for copper (Cu) wiring layers. The parameters of the SEEF model in each layer depend not only on the density and thickness of the material but also on the depth of the material in the substrate. Moreover, as the number of underlying layers including metals increases, the number of parameters of the SEEF model increases; thus, the difficulty in parameter extraction markedly increases. We have attempted to extract the optimum parameters of the SEEF model in each layer using the MC simulation. As a result, it was found that the differences in the backscattered electron energy fluxes from several layers with different combinations of Cu densities between the SEEF model and the MC simulation were within a range from -1.56 to +0.74%.