Numerical simulation study of barrier inhomogeneities at Schoktty contacts

The Poisson equation and the drift diffusion equations have been used to simulate the current-voltage characteristics of inhomogeneous Schottky contact having discrete distribution of different barrier height patches. The potential variation inside the bulk semiconductor near the metal-semiconductor contact was estimated first and then the current as a function of bias through the Schottky diode using silicon parameters were calculated for various discrete distribution patterns of barrier heights. From the simulated current-voltage characteristics the apparent diode parameters were extracted by fitting of current-voltage data into thermionic emission diffusion current equation. The derived barrier parameters are analyzed to study the effect of barrier inhomogeneities on the current-voltage characteristics of Schottky contact.