Wide Bandgap Vertical kV-Class β-Ga₂O₃/GaN Heterojunction p-n Power Diodes With Mesa Edge Termination

Abstract

Breakdown capability of β-Ga2O3/GaN heterojunction-based vertical p-n power diodes with mesa edge termination (ET) was comprehensively investigated using TCAD simulation. With 5 μm β-Ga2O3 drift layer, the ideal breakdown voltage (BV) of the heterojunction was 1.37 kV, while the BV of the reference device without effective mesa edge termination decreased dramatically to 300 V due to the electric field crowding at the device edge. Four mesa ET structures were investigated to mitigate the electric field crowding at the junction edge, including beveled mesa, step mesa, deeply etched mesa, and p-doped guard ring. Without effective ET, the peak electric field at the junction edge was ~ 4.2 MV/cm at −300 V. By incorporating these ET techniques, the peak electric fields were reduced significantly to 0.73 MV/cm. Ideal BV of 1.37 kV was achievable using deeply etched mesa and guard ring ETs. The beveled mesa realized >80% of the ideal BV, while step mesa ET was less effective in alleviating the electric field crowding and only offered ~ 40% of the ideal BV. The device BV can be further scaled by varying β-Ga2O3 drift layer thickness. This work can serve as an important reference and guideline for developing high power high voltage β-Ga2O3 based bipolar power devices.

Enhancement-mode vertical (100) β-Ga2O3 FinFETs with an average breakdown strength of 2.7 MV cm−1

“…Nevertheless, these investigations emphasize that the realization of additional edge termination structures are mandatory in order to improve the electric field distribution in the edge region and reduce those field peaks. Several approaches can be followed to achieve this as previously demonstrated with vertical SBDs such as mesa structuring, 29,30) ion implantation 31,32) or additional deposition of p-type guard rings. 33,34)…”

β-Ga2O3-Based Heterostructures and Heterojunctions for Power Electronics: A Review of the Recent Advances

“…Figure 11i shows the I-V characteristics of the p-n heterojunction with β-Ga 2 O 3 thicknesses of 100 nm and 5 and 20 µm, indicating similar electrical characteristics across the different thicknesses. Mudiyanselage et al [105] conducted theoretical investigations into edge termination structures for this p-n heterojunction, utilizing a 5 µm thick β-Ga 2 O 3 drift layer, which has enabled the development of kV-class power diodes. Nandi et al [106] have conducted research on JBS diodes utilizing this heterostructure, examined the switching characteristics of the devices, and obtained information on the reverse recovery behavior.…”

GaSe/<i>β</i>-Ga₂O₃ heterojunction based self-powered solar-blind ultraviolet photoelectric detector

“…例如Yuan等 [20] 通过分子束外延(MBE)方 法在硅片上沉积GaSe形成了垂直范德瓦耳斯异 质结构, 用作光电二极管实现了高效快速的光响 应. Ben等 [21] 通过范德瓦耳斯外延在石墨烯上合成 GaSe原子层, 实现了异质结构的强电荷转移. GaSe I n P r e s s 分光光度计测量样品的光谱吸收特性 [23] , 从而计 算出光学带隙.用 X 射线衍射仪(XRD)研究样品 的晶体结构, 用场发射扫描电子显微镜(FE-SEM, 日立Regulus 8220)分别对Ga 2 O 3 和GaSe所得样 品表面和断面进行了表征, 用 Q-6 紫外-可见(UV-Vis)分光光度计测量样品的光谱吸收特性 [23] , 从 而计算出光学带隙.…”