Effects of Barrier Height Inhomogeneity on Core Level Photoemission from Clean and Metal-Covered Semiconductor Surfaces.

A novel approach to the analysis of photoemission core level line shape changes, which occur as a function of temperature, doping level, and metal coverage, is presented. It demonstrates that core level photoemission spectroscopy from semiconductor surfaces and metal-semiconductor interfaces may be affected by barrier height inhomogeneities which can alter the shape of the measured Lines. A simple model is used to predict the effect of such local variations on the shape of core level emission. We show that a strong correlation between photoemission data and barrier heights inhomogeneity exists which need to be taken into account in order to correctly interpret photoemission results.