Monte Carlo simulation of electron transmission through the scattering masks with angular limitation for projection electron lithography.

We calculated electron energy loss and angular distributions for electrons transmitted through masks for electron projection lithography by a Monte Carlo (MC) simulation method. After comparing the improved continuous slowing down approximation model, the direct MC model, and the intensive direct MC model, the last model was used. The energy loss distributions calculated by the latter two models are much better than by the first model and the intensive direct MC model can be applied to more materials than the direct MC model. The effect of mask thickness on energy loss, transmission, and contrast was analyzed. We found that, for a W/Cr/Si[sub 3]N[sub 4] mask, the thicker the scattering layer the wider the angular distribution, the lower the transmission, and the higher the contrast. But the thickness of the membrane Si[sub 3]N[sub 4] layer has less effect on the contrast. [ABSTRACT FROM AUTHOR]