Simulation Study of Performance Degradation in β-Ga2O3 (001) Vertical Schottky Barrier Diodes Based on Anisotropic Mobility Modeling

Beta-gallium oxide (beta-Ga2O3) devices exhibit the degradation of on-state characteristics compared with the theoretical expectation according the recent reports. Simulation of electrical properties in devices should, therefore, include model calibration valid up to such situation. In this paper, the anisotropic mobility modeling has been incorporated to calculate the electrical performances of beta-Ga2O3 (001) vertical SBDs. This model parameters were revised through a series of reported experimental data, which presents that the electron mobility anisotropic ratio of 7 between two orthogonal directions ([100] and the normal of (001) orientation), resulting in much reduced mobility perpendicular to the device surface. Additionally, the forward characteristics and reverse recovery properties of beta-Ga2O3 SBDs over range of 300-500 K were investigated by means of calibrated anisotropic mobility model. As a result, the on-resistance is much increased mainly leading to the degradation of the static forward mode, while a lower reverse current peak (Irr) for switching characteristics. The modified mobility modeling considering anisotropy provides a precise curve-fitting to the measurements of on-state characteristics of beta-Ga2O3 SBDs, enabling a more accurate prediction of device performance.