MODELING OF ELECTRON ELASTIC AND INELASTIC-SCATTERING

The role of the form of the elastic and inelastic cross section in Mon te Carlo simulations of electron-solid scattering has been studied to understand the processes whereby energy is deposited by electrons as t hey traverse thin films. Specifically we are interested in these pheno mena as they relate to proximity effects in electron-beam lithography and the detection of electrons by a Schottky diode with a patterned ab sorber overlayer. Lithographic point and line spread functions have be en measured in three resist materials. We show that the inclusion of d iscrete inelastic scattering events whereby fast secondaries are gener ated is essential for matching simulation and experiment. The secondar ies are crucial in determining the shape of the spread functions in th e 0.1-1 mu m regime and must be included to model proximity effects. F urther, the fitting of line spread function simulations to experiment allows the accurate prediction of dot spread functions and applied dos e thresholds as well as three dimensional resist profiles. The form of the elastic cross section is important in determining the energy loss in, and transmission through, thin metallic films. For electron energ ies where the film transmission is low, the Mott cross section provide s a more accurate simulation than the screened Rutherford cross sectio n.