Numerical simulation of the piezoresistive effect of βGa2O3 in the direction

Abstract
β-Ga2O3 has high potential for power device applications because of a high Baliga's figure and the availability of large-scale wafers. However, the piezoresistive effect of β-Ga2O3 has not been investigated in detail, and its piezoresistive coefficient has not been reported. This study evaluates the piezoresistive coefficient of β-Ga2O3 in the direction using a mechanical stress simulator and a device simulator, which includes our piezoresistive effect model. In this study, the piezoresistive effect model and simulation method are applied to β-Ga2O3 for the first time. The piezoresistor model of β-Ga2O3 is simulated to evaluate the piezoresistive coefficient of β-Ga2O3. The experimentally obtained gauge factor (GF) with and without the contact effect is -5.8 and -3.6, respectively. The piezoresistive coefficient with and without the contact effect is -2.0×10−11 Pa−1 and -1.2×10−11 Pa−1, respectively. The piezoresistive coefficient is used to evaluate the piezoresistive effect at 1000◦C through thermal analysis.