Prediction of anisotropic short circuit robustness of vertical β -Ga₂O₃ MOSFET

Abstract The short-circuit robustness of the 800 V β -Ga₂O₃ vertical MOSFET is systematically studied by 2D technology computer aided-design simulation. To acquire more realistic short-circuit characteristics, parameters including the temperature-dependent lattice heat capacity, thermal conductivity and mobility of β -Ga₂O₃ are precisely modeled. The short-circuit characteristics of β -Ga₂O₃ vertical MOSFETs with different crystal orientations are presented in this work. The results show that, with a 400 V bus voltage and 1300 A cm −2 short-circuit current, the short-circuit withstand times (SCWTs) of [100] and [001] crystal-oriented Ga₂O₃ vertical MOSFET are 3.1 μ s and 3.2 μ s respectively, and that of the [010] orientation exceeds 15 μ s. In order to improve the short-circuit robustness of vertical Ga₂O₃ MOSFET, the influence of channel length on SCWT is investigated in detail. Under the same test conditions ( V bus = 600 V, V gs = 8 V), the channel length increases from 1 μ m to 2 μ m, the specific on-resistance of [001] oriented MOSFET increases by 1.8 times, and the SCWT in-creases from < 1 μ s to > 7 μ s. These findings provide a valuable reference for the design and manufacture of high-reliability Ga₂O₃ vertical MOSFETs for power switching applications