1.5 kV Vertical Ga2O3Trench-MIS Schottky Barrier Diodes

摘要

$beta-mathrm{Ga}_{2}mathrm{O}_{3}$nelectronic devices for high power applications have seen rapid development over the recent years, due to the excellent material properties including an extremely large band-gap, high critical electric field, decent electron mobility and the availability of low-cost bulk substrates. As unipolar devices, Gan2nOn3nvertical Schottky barrier diodes (SBDs) have fast switching capability, while enjoying all the superior properties of Gan2nOn3n. With the development of halide vapor phase epitaxy (HVPE) capable of delivering high quality thick nn^–nepitaxial layers [1],n$mathrm{Ga}_{2}mathrm{O}_{3}$nvertical SBDs have shown promising results with up to 1 kV breakdown voltage (BV) together with decent on-resistancen$(mathrm{R}_{mathrm{on}})$nofn$2-6 mathrm{m}Omegacdot mathrm{cm}^{2} [1-3]$n. However, the results are still far from the projected performance which surpasses GaN and SiC [4]. One important reason is the high reverse leakage current due to the high surface electric field, which causes thermionic-field emission and barrier height lowering, especially at the device edge where field crowding occurs. The leakage current can be much reduced by edge termination techniques such as field-plating [3]. More effectively, a trench-metal-insulator-semiconductor (MIS) structure can be utilized to reduce the leakage current [5], taking advantage of the reduced surface field (RESURF) effect [6]. In this work, we demonstrate Gan2nOn3ntrench-MIS SBDs with a record-high 1.5 kV breakdown voltage without edge termination, together with a ~10n⁴ntimes reduction in reverse leakage current compared with regular SBDs.