A 2.8 kV Breakdown Voltage α-Ga2O3 MOSFET with Hybrid Schottky Drain Contact

Seung Yoon Oh; Yeong Je Jeong; Inho Kang; Ji-Hyeon Park; Min Jae Yeom; Dae-Woo Jeon; Geonwook Yoo

doi:10.3390/mi15010133

A 2.8 kV Breakdown Voltage α-Ga₂O₃ MOSFET with Hybrid Schottky Drain Contact

Micromachines (Basel). 2024 Jan 14;15(1):133. doi: 10.3390/mi15010133.

Authors

Seung Yoon Oh¹, Yeong Je Jeong², Inho Kang³, Ji-Hyeon Park⁴, Min Jae Yeom², Dae-Woo Jeon⁴, Geonwook Yoo^{1

2}

Affiliations

¹ Department of Intelligent Semiconductor, Soongsil University, Seoul 06938, Republic of Korea.
² School of Electronic Engineering, Soongsil University, Seoul 06938, Republic of Korea.
³ Power Semiconductor Research Division, Korea Electrotechnology Research Institute, Changwon 51543, Republic of Korea.
⁴ Korea Institute of Ceramic Engineering & Technology, Jinju 52851, Republic of Korea.

Abstract

Among various polymorphic phases of gallium oxide (Ga₂O₃), α-phase Ga₂O₃ has clear advantages such as its heteroepitaxial growth as well as wide bandgap, which is promising for use in power devices. In this work, we demonstrate α-Ga₂O₃ MOSFETs with hybrid Schottky drain (HSD) contact, comprising both Ohmic and Schottky electrode regions. In comparison with conventional Ohmic drain (OD) contact, a lower on-resistance (R_on) of 2.1 kΩ mm is achieved for variable channel lengths. Physics-based TCAD simulation is performed to validate the turn-on characteristics of the Schottky electrode region and the improved R_on. Electric-field analysis in the off-state is conducted for both the OD and HSD devices. Furthermore, a record breakdown voltage (BV) of 2.8 kV is achieved, which is superior to the 1.7 kV of the compared OD device. Our results show that the proposed HSD contact with a further optimized design can be a promising drain electrode scheme for α-Ga₂O₃ power MOSFETs.

Keywords: MOSFET; Ohmic drain; breakdown voltage; hybrid Schottky drain; α-Ga2O3.

Grants and funding

This research was supported by NRF (2021R1F1A1058006) funded by the Ministry of Education, Republic of Korea, and by KEIT grant (RS-2022-00154729) funded by the Korea Government (MOTIE).