【Device Papers】Radiation-Hardened Ga₂O₃ MOSFET Design Featuring NiO Heterojunction and Comb-Shaped Gate Modulation

      Researchers from Chongqing University of Posts and Telecommunications have published a dissertation titled " Radiation-Hardened Ga₂O₃ MOSFET Design Featuring NiO Heterojunction and Comb-Shaped Gate Modulation " in 电子与信息学报。

Abstract

      Gallium Oxide Metal-Oxide-Semiconductor Field-Effect Transistor (Ga₂O₃ MOSFET) is regarded as a promising power device for high-voltage applications, particularly in aerospace and satellite power systems, because of its ultra-wide bandgap and high critical breakdown field. However, the Conventional MOSFET (C-MOSFET) exhibits limited reliability in space radiation environments. Under off-state conditions, the electric field is highly concentrated near the gate edge. Heavy-ion irradiation generates dense electron-hole pairs along the ion track. Driven by the intense electric field, these carriers undergo avalanche multiplication through impact ionization, causing the drain current to increase sharply without recovery and ultimately leading to irreversible Single-Event Burnout (SEB) at relatively low drain bias. This failure mechanism severely limits the application of Ga₂O₃ MOSFETs in harsh radiation environments. Furthermore, the lack of reliable and efficient p-type doping restricts the implementation of conventional radiation-hardening techniques, including junction termination extension and junction isolation. Therefore, ionization-induced carriers readily accumulate in sensitive regions, increasing susceptibility to Single-Event Effect (SEE). The extremely low thermal conductivity of Ga₂O₃ further promotes local heat accumulation following heavy-ion irradiation, producing localized hot spots that increase the likelihood of thermal burnout. Existing hardening approaches, including field-plate optimization and dielectric engineering, provide only limited improvement. Moreover, the application of heterojunction structures for radiation hardening has rarely been investigated, and systematic hardening strategies have not yet been established. To address these limitations, this paper proposes a Comb-Shaped Gate Metal-Oxide-Semiconductor Field-Effect Transistor (CSG-MOSFET) incorporating a NiO heterojunction. The proposed structure redistributes the channel electric field, suppresses electric-field crowding at the conventional gate edge, and significantly improves SEB tolerance, providing an effective solution for Ga₂O₃ power devices operating in harsh radiation environments. 

DOI：

https://doi.org/10.11999/JEIT260396