First Demonstration of Ga2O3 Trench MOS-Type Schottky Barrier Diodes

We developed β-Ga
₂
O
₃
trench MOS-type Schottky barrier diodes (MOSSBDs) for the first time. A Sidoped Ga
₂
O
₃
layer was grown via halide vapor phase epitaxy on a single-crystal Sn-doped β-Ga
₂
O
₃
(001) substrate. The trench structure was fabricated using dry etching and photolithography. HfO
₂
film 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 mΩcm
²
, 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 Ga
₂
O
₃
is highly effective for decreasing the reverse leakage current.