Extending Electrostatic Modeling for Schottky p-GaN Gate HEMTs: Uniform and Engineered p-GaN Doping

Abstract

This article presents a comprehensive analytical framework for modeling p-GaN gate high-electron-mobility transistors (HEMTs) based on rigorous solution of the Poisson and Schrodinger equations. It focuses primarily on the calculation of the 2-D electron gas (2DEG), voltage variation across the junction (Delta V-j), and AlGaN barrier ( Delta V-b) for the entire range of forward gate bias until gate breakdown. Our model considers the impact of AlGaN barrier height saturation. In addition, we demonstrate our model with the engineered p-GaN doping profile that yields higher forward gate breakdown voltages. Gate capacitance and breakdown voltage have been modeled for both uniform and engineered p-GaN doping profiles. The viability and accuracy of the proposed model are demonstrated through comparisons with empirical measurement data and TCAD simulations.