Enhancement of positive bevel /3-Ga2O3 trench MOS barrier Schottky diode by post-etching treatment

A /3-Ga2O3 trench MOS barrier Schottky (TMBS) diode with a novel terminal structure of positive bevel mesa and arc bottom corners has been designed and realized in this work. O2 plasma, hydrogen fluoride (HF), and tetramethylammonium hydroxide (TMAH) are used for post-etching treatment of devices, respectively. Measurement results shows that the specific on-resistance of the three devices are nearly with the same value of 2.60 m Omega & sdot;cm2. The breakdown voltage of the devices with O2 plasma, HF, and TMAH treatments are 1280 V, 1440 V, and 1800 V, respectively. Moreover, it is worth nothing that devices treated with O2 plasma have a lower reverse leakage. In addition, the breakdown location of the device is determined to be at the /3-Ga2O3 interface under the edge of the field plate by combining simulation and capacitance breakdown testing. AFM and XPS are used to analyze the surface properties of /3-Ga2O3 after post-etching treatments. The results show that the TMAH treatments have the most significant effect on reducing surface roughness, and the O2 plasma treatments is the most effective in decreasing oxygen vacancies.