Comprehensive Study and Optimization of Implementing p-NiO in β-Ga2O3 Based Diodes via TCAD Simulation

In this paper, we carried out a comprehensive study and optimization of implementing p-NiO in the β-Ga2O3 based diodes, including Schottky barrier diode (SBD) with p-NiO guard ring (GR), p-NiO/β-Ga2O3 heterojunction (HJ) barrier Schottky (HJBS) diode, and HJ-PN diode through the TCAD simulation. In particular, we provide design guidelines for future p-NiO-related Ga2O3 diodes with material doping concentrations and dimensions to be taken into account. Although HJ-PN has a ~1 V higher turn-on voltage (Von), its breakdown voltage (BV) is the highest among all diodes. We found that for SBD with p-NiO GRs and HJBS, their forward electrical characteristics and reverse leakage current are related to the total width and the doping concentration of p-NiO, the BV is only related to the doping concentration of p-NiO, and the optimal doping concentration of p-NiO is found to be 4 × 1017 cm−3. Compared with the SBD without p-NiO, the BV of the SBD with p-NiO and HJBS diode can be essentially improved by 3 times. As a result, HJ-PN diode, SBD with p-NiO GRs, and HJ-BS diode achieve a BV/specific on-resistance (Ron,sp) of 5705 V/4.3 mΩ·cm2, 3006 V/3.07 mΩ·cm2, and 3004 V/3.06 mΩ·cm2, respectively. Based on different application requirements, this work provides a useful insight about the diode selection with various structures.