NiO junction termination extension for high-voltage (>3 kV) Ga2O3 devices

Edge termination is the enabling building block of power devices to exploit the high breakdown field of wide bandgap (WBG) and ultra-wide bandgap (UWBG) semiconductors. This work presents a heterogeneous junction termination extension (JTE) based on p-type nickel oxide (NiO) for gallium oxide (Ga2O3) devices. Distinct from prior JTEs usually made by implantation or etch, this NiO JTE is deposited on the surface of Ga2O3 by magnetron sputtering. The JTE consists of multiple NiO layers with various lengths to allow for a graded decrease in effective charge density away from the device active region. Moreover, this surface JTE has broad design window and process latitude, and its efficiency is drift-layer agnostic. The physics of this NiO JTE is validated by experimental applications into NiO/Ga2O3 p–n diodes fabricated on two Ga2O3 wafers with different doping concentrations. The JTE enables a breakdown voltage over 3.2 kV and a consistent parallel-plate junction field of 4.2 MV/cm in both devices, rendering a power figure of merit of 2.5–2.7 GW/cm2. These results show the great promise of the deposited JTE as a flexible, near ideal edge termination for WBG and UWBG devices, particularly those lacking high-quality homojunctions.

[1]  S. Rajan,et al.  β-Ga2O3 Schottky barrier diodes with 4.1 MV/cm field strength by deep plasma etching field-termination , 2022, Applied Physics Letters.

[2]  F. Udrea,et al.  Multidimensional device architectures for efficient power electronics , 2022, Nature Electronics.

[3]  Honggyun Kim,et al.  Demonstration of 4.7 kV breakdown voltage in NiO/β-Ga2O3 vertical rectifiers , 2022, Applied Physics Letters.

[4]  M. Si,et al.  Ultra-wide bandgap semiconductor Ga2O3 power diodes , 2022, Nature Communications.

[5]  M. Schubert,et al.  A review of band structure and material properties of transparent conducting and semiconducting oxides: Ga2O3, Al2O3, In2O3, ZnO, SnO2, CdO, NiO, CuO, and Sc2O3 , 2022, Applied Physics Reviews.

[6]  O. Bierwagen,et al.  β-Gallium oxide power electronics , 2022, APL Materials.

[7]  F. Ren,et al.  β-Ga2O3 vertical heterojunction barrier Schottky diodes terminated with p-NiO field limiting rings , 2021 .

[8]  Rong Zhang,et al.  β-Ga2O3 hetero-junction barrier Schottky diode with reverse leakage current modulation and BV2/Ron,sp value of 0.93 GW/cm2 , 2021 .

[9]  M. Hudait,et al.  Tri-gate GaN junction HEMT , 2020 .

[10]  D. Jena,et al.  Thermionic emission or tunneling? The universal transition electric field for ideal Schottky reverse leakage current: A case study inβ-Ga2O3 , 2020, 2008.07624.

[11]  F. Ren,et al.  A 1.86-kV double-layered NiO/β-Ga2O3 vertical p–n heterojunction diode , 2020 .

[12]  D. Jena,et al.  Near-ideal reverse leakage current and practical maximum electric field in β-Ga2O3 Schottky barrier diodes , 2020 .

[13]  Stephen J. Pearton,et al.  A review of Ga2O3 materials, processing, and devices , 2018 .

[14]  Akito Kuramata,et al.  1-kV vertical Ga2O3 field-plated Schottky barrier diodes , 2017 .

[15]  J. Ao,et al.  NiO/GaN heterojunction diode deposited through magnetron reactive sputtering , 2016 .

[16]  K. Chattopadhyay,et al.  Effect of oxygen partial pressure on the electrical and optical properties of highly (200) oriented p-type Ni1−xO films by DC sputtering , 2007 .

[17]  F. Ren,et al.  Effect of probe geometry during measurement of >100 A Ga2O3 vertical rectifiers , 2021 .

[18]  Stephen J. Pearton,et al.  2300V Reverse Breakdown Voltage Ga2O3 Schottky Rectifiers , 2018 .