Simulation Study of Gallium Oxide Metal-Oxide-Semiconductor Devices

Abstract

In this presentation, our recent research activities on the gallium oxide (Ga2O3) devices are described. The metal-oxide-semiconductor (MOS) structure, where the aluminum oxide (Al2O3) layer is used as a gate dielectric layer, is considered. First, the defect levels in the Al2O3/Ga2O3 interface are calculated by using the density-functional theory calculation method. It is found that the vacancies give the defect levels close to the conduction band minimum. The mobility of the two-dimensional electron gas (2DEG) in the Ga2O3 double-gate MOS structure is calculated by using our in-house simulation tool. By changing the thickness of the Ga2O3 layer, the 2DEG mobility is calculated as a function of the electron sheet density. Finally, the vertical Ga2O3 MOSFET with the fin shaped source is simulated by using the commercial semiconductor device simulator. The simulation results of the vertical MOSFET are compared with the measurement results, which are taken from the references. The impact of the fin shape on the electrical performance, such as the on-resistance and the drain-induced barrier lowering, is numerically investigated.