BEEM studies of the PtSi/Si(100) interface electronic structure

Abstract

Abstract The aim of the present work is a comparative study by ballistic electron emission microscopy (BEEM) of PtSi/n-Si(100) interface electronic structures using the assumption of an energy-dependent transmission coefficient or an energy-independent transmission coefficient and the possible explanation of the standard deviation of the barrier height from the most probable barrier height. PtSi/n-Si(100) interfaces have been studied for PtSi layers with an average estimated thickness of 2–3 nm. Locally measured barrier heights show distributions with the most probable values of barrier heights between 0.734 eV and 0.829 eV and with standard deviations from these most probable values of barrier heights in the range 0.010–0.066 eV. The assumption of an energy-independent coefficient for transmission of electrons through the interface is more preferable since the treatment of experimental results using a square-law leads to a most probable value of the barrier height in accordance to other measurements. The standard deviations of barrier heights from the most probable barrier heights may be explained by the heterogeneity of the PtSi layer thickness. The experimental results show lower barrier height for a higher PtSi layer thickness. The decreasing barrier height is accompanied by an increasing amount of Pt interstitial atoms.