First Demonstration of Ga₂O₃Trench MOS-Type Schottky Barrier Diodes

We developed β-Ga2O3trench MOS-type Schottky barrier diodes (MOSSBDs) for the first time. A Sidoped Ga2O3layer was grown via halide vapor phase epitaxy on a single-crystal Sn-doped β-Ga2O3(001) substrate. The trench structure was fabricated using dry etching and photolithography. HfO2film was used as the dielectric film of the trench MOS structure. The specific on-resistances (RON,SP) of the normal SBD and trench MOSSBD were about 2.3 and 2.9 mΩcm2, respectively. The reason the RON,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 electric field at the anode metal/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 Ga2O3is highly effective for decreasing the reverse leakage current.