The Effects of a Gate Bias Condition on 1.2 kV SiC MOSFETs during Irradiating Gamma-Radiation

Chaeyun Kim; Hyowon Yoon; Yeongeun Park; Sangyeob Kim; Gyuhyeok Kang; Dong-Seok Kim; Ogyun Seok

doi:10.3390/mi15040496

The Effects of a Gate Bias Condition on 1.2 kV SiC MOSFETs during Irradiating Gamma-Radiation

Micromachines (Basel). 2024 Apr 4;15(4):496. doi: 10.3390/mi15040496.

Authors

Chaeyun Kim¹, Hyowon Yoon², Yeongeun Park², Sangyeob Kim², Gyuhyeok Kang², Dong-Seok Kim³, Ogyun Seok⁴

Affiliations

¹ Department of Electronic Engineering, Kumoh National Institute of Technology, Gumi-si 39177, Republic of Korea.
² Department of Semiconductor System Engineering, Kumoh National Institute of Technology, Gumi-si 39177, Republic of Korea.
³ Korea Atomic Energy Research Institute, Gyeongju-si 38180, Republic of Korea.
⁴ School of Electronic Engineering, Kumoh National Institute of Technology, Gumi-si 39177, Republic of Korea.

Abstract

We investigated the effects of gate bias regarding the degradation of electrical characteristics during gamma irradiation. Moreover, we observed the punch through failure of 1.2 kV rated commercial Silicon Carbide (SiC) Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) due to the influence of gate bias. In addition, the threshold voltage (V_T) and on-resistance (R_on) of the SiC MOSFETs decreased significantly by the influence of gate bias during gamma irradiation. We extracted the concentration of carriers and fixed charge (Q_F) in oxide using N-type SiC MOS capacitors and Transmission Line Measurement (TLM) patterns to analyze the effects of gamma irradiation. The Total Ionizing Dose (TID) effect caused by high-energy gamma-ray irradiation resulted in an increase in the concentration of holes and Q_F in both SiC and oxide. To analyze the phenomenon for increment of hole concentration in the device under gate bias, we extracted the subthreshold swing of SiC MOSFETs and verified the origin of TID effects accelerated by the gate bias. The Q_F and doping concentration of p-well values extracted from the experiments were used in TCAD simulations (version 2022.03) of the planar SiC MOSFET. As a result of analyzing the energy band diagram at the channel region of 1.2 kV SiC MOSFETs, it was verified that punch-through can occur in 1.2 kV SiC MOSFETs when the gate bias is applied, as the TID effect is accelerated by the gate bias.

Keywords: SiC MOSFET; gamma-ray; power device; radiation; total ionizing dose.

Grants and funding

This work has been supported through the “Regional Industry-based Talent Development and Developing Innovative Technology” Program and the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MIST) (No. NRF-2021M3C1C3097674).