TEMP: A software package for simulation of resist heating in electron beam lithography
A new software package TEMP (Thermal Effect Modelling Programs) has been developed to simulate resist heating effects in high throughput e-beam lithography for photomask manufacturing. The TEMP package is based entirely on numerical methods. It consists of three simulators; the energy deposition simulator by 3-D Monte Carlo method, the thermal diffusion simulator by 3-D finite difference method and the resist development simulator by 3-D cell removal method. A new double-cell numerical scheme was developed to achieve high accuracy of temperature information for fine pattern structures without high demand on computer memory. The change of resist sensitivity due to heating was experimentally characterised by a heating stage constructed inside an e-beam lithography system. The resist layer was exposed while it was being heated at different temperatures. The measured sensitivity variations due to heating were fitted into an empirical model and is employed in the resist development simulator, so that the 3-D developed resist images with heating effects can be simulated.