Surge current capability of ultra-wide-bandgap Ga2O3 Schottky diodes

Abstract

β-Ga2O3 is an emerging ultra-wide-bandgap semiconductor material offering superior power material limits over Si, SiC, and GaN as well as the availability of large-diameter wafers growing from its own melt. However, β-Ga2O3 devices performance may be limited by the relatively poor thermal conductivity of the material.In this paper, we investigate the behavior of β-Ga2O3 Schottky diodes in the condition of forward current surge to explore their electro-thermal ruggedness and the related thermal management. An analytical electro-thermal device model is calibrated with experimental devices and TCAD simulations. Then this device model is incorporated into a SPICE electro-thermal network model, which is used to simulate the device temperature rise during the surge transient, considering various device and packaging configurations (i.e. various chip thicknesses and chip orientations).It is found that provided heat is removed from the junction side, a β-Ga2O3 Schottky diode offers a robustness to surge current exceeding that of a SiC Schottky diode. The low thermal conductivity of β-Ga2O3 is found to be overcome by the enhanced heat extraction from junction-side cooling, as well as by the intrinsically small temperature dependence of the on-resistance (and conduction loss) of β-Ga2O3 devices.