A New Approach to the Monte Carlo Prediction of Interface Phenomena

A new method for more efficient Monte Carlo prediction of interface phenomena in highly shielded and/or complex geometries is described. It is based upon the internal generation of an interface source surrounding the relatively small portion of a problem where interface effects are most important. The method is verified by comparing with a more conventional Monte Carlo approach for a case where the latter can be efficiently employed. It is applied to the prediction of forward photoemission for both scattering and absorption dominated situations and to the prediction of energy deposition profiles near a gold/silicon interface that is both highly shielded and subject to significant backscatter. Although run times are quite high, primarily due to the large spread in weights of the contributing electrons, there may be no alternatives to this approach for complex geometries.