Unpinning the relationship between pinning factor and electronegativity by calculating Schottky barrier heights from first principles*

We calculate the Schottky barriers that develop at the interface between a metal and semiconductor. These barriers govern the current-rectification ability of Schottky diodes and the electrical response of metal-semiconductor field effect transistors. A model that accounts for the alignment of the electronic levels across the metal-semiconductor interface and the long-range polarization within the space charge region enables us to predict the heights of the barriers as a function of the electronic offsets, including the effects of charge trapping and Fermi-level pinning. We validate our computational predictions against experimental measurements [1], providing a detailed understanding of trends in the pinning factor, i.e., the change in the Schottky barrier height as a function of the metal work function. The resulting model provides a comprehensive first-principles approach to simulate the characteristics of semiconductor-metal junctions under bias.

[1] S. Kurtin et al., J. Phys. Chem. Solids, 30, 2007-9 (1969).