Surge Current Capability of Ga2O3 Schottky Diodes

International audience ; β-Ga2O3 is an attractive material to build power electronic semiconductor devices, because because of its ultra-wide bandgap and the availability of large-diameter wafers growing from its own melt. However, device 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. 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, single-side or double-side cooling). It is found that providing heat is removed through both sides of the die, a β-Ga2O3 Schottky diode offers a robustness to surge current comparable to that of a SiC Schottky diode. The low thermal conductivity of β-Ga2O3 is found to be balanced by the enhanced heat extraction from top-side cooling as well as the intrinsic low on-resistance (and conduction loss) increase with temperature in β-Ga2O3 devices.