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

Jincheng Zhang,Qian Feng,Yue Hao,Shengrui Xu,Hong Zhou,Jinfeng Zhang,Zhihong Liu,Shifan Zeng

doi:10.3390/cryst11101186

Abstract

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.

Highlights

Beta-phase Ga2O3 (β-Ga2O3) has attracted tremendous attention as a promising material for power electronic applications because of its excellent physical properties, such as wide energy band gap of 4.6–4.9 eV, estimated high critical breakdown electric field of 8 MV/cm, decent electron mobility of 250 cm2/Vs with high electron saturation velocity of 2 × 107 cm/s, and the cost-effective substrate through melt-grown methodology [1,2,3,4,5]
Due to the challenge of acquiring p-type Ga2O3, most research attention is paid to unipolar devices, including both the lateral and vertical field effect transistors (FETs) and diodes [7,8,9,10,11,12]
A significant amount of research is invested in improving the diode performance and many advanced edge termination techniques are being developed, including implanted edge termination, field plate, and Fin-type trench structures

Summary

Introduction

Beta-phase Ga2O3 (β-Ga2O3) has attracted tremendous attention as a promising material for power electronic applications because of its excellent physical properties, such as wide energy band gap of 4.6–4.9 eV, estimated high critical breakdown electric field of 8 MV/cm, decent electron mobility of 250 cm2/Vs with high electron saturation velocity of 2 × 107 cm/s, and the cost-effective substrate through melt-grown methodology [1,2,3,4,5]. Due to the challenge of acquiring p-type Ga2O3, most research attention is paid to unipolar devices, including both the lateral and vertical field effect transistors (FETs) and diodes [7,8,9,10,11,12]. The calculated valence band structure is found to be extremely flat, leading to a large hole effective mass; subsequently, the holes can be regarded as polartons and even the acceptor can ionize holes [14,15]

Methods

Results

Conclusion