First Demonstration of Ga2O3 Trench MOS-Type Schottky Barrier Diodes

We developed beta-Ga2O3 trench MOS-type Schottky barrier diodes (MOSSBDs) for the first time. A Si-doped Ga2O3 layer was grown via halide vapor phase epitaxy on a single-crystal Sn-doped beta-Ga2O3 (001) substrate. The trench structure was fabricated using dry etching and photolithography. HfO2 film was used as the dielectric film of the trench MOS structure. The specific on-resistances (R-ON, (SP)) of the normalSBDand trenchMOSSBDwere about 2.3 and 2.9 m Omega cm(2), respectively. The reason the R-ON, (SP) of MOSSBD was a little higher than that of the Schottky barrier diodes (SBD) is that the current path decrease as a result of forming the trench MOS structure. The normal SBD had a large reverse leakage current due to the large electricfield at the anodemetal/semiconductorinterface. On the other hand, the trench MOSSBD had several orders of magnitude smaller leakage current. We, thus, demonstrated that incorporating the trench MOS structure in Ga2O3 is highly effective for decreasing the reverse leakage current.