Comparison of inhomogeneous Schottky barrier modeling approaches in SiC polytypes.

Abstract

This work presents a comprehensive comparative analysis of Schottky barrier (SB) inhomogeneities in three SiC polytypes (3C, 4H, and 6H) using three established theoretical approaches: the Cowley and Sze interface state model, the Werner Gaussian distribution model, and the Tung localized patch model. Through analytical simulations performed in MATLAB, we examined how each model's intrinsic parameters, including the interface state density (Nss), the standard deviation (σ), and the inhomogeneity parameter (γ), influence the effective Schottky barrier height (SBH) and the corresponding I-V characteristics predicted by each model. Our results demonstrate that each model reveals a distinct physical mechanism governing charge transport at the metal/semiconductor interface. The Cowley and Sze model emphasizes Fermi-level pinning due to interface states, Werner's model accounts for statistical fluctuations of the barrier height, and Tung's model describes localized current flow through low-barrier patches. Even though the numerical values obtained for each case are different, Although the three SiC polytypes exhibit different quantitative responses, they all show thermally activated transport behavior. These findings provide valuable guidelines for optimizing Schottky contact performance in high- temperature SiC power devices. The proposed comparative framework serves as a predictive tool for designing, engineering, and improving metal/SiC interfaces in advanced power device technologies.