Software tool for advanced Monte Carlo simulation of electron scattering in EBL and SEM: CHARIOT

An advanced Monte Carlo model and software were developed to simulate electron scattering in electron beam lithography and signal formation in scanning electron microscopy at a new level of accuracy required for lithography and metrology. The model involves generation of fast secondary and slow secondary electrons, as well as generation of volume plasmons, and electron transfer between layers with regard to the difference between work functions of layers. To track SEM detector channel, the geometry of a detector and its energy transfer function were taken into account. This advanced model was used to simulate electron trajectories, deposited energy, signal from electron detector and images in SEM. Examples of simulations are presented for electron spectra, energy deposition in 50 W maskmaking, and signals from patterned wafers in SEM.