Effect of X-Ray Irradiation on Threshold Voltage of AlGaN/GaN HEMTs with pGaN and MIS Gate

TL;DR

This study compares the effects of X-ray radiation on GaN HEMT devices with pGaN and MIS gates, showing pGaN gates offer greater stability of threshold voltage under radiation, making them suitable for space applications.

Contribution

It provides a comparative analysis of radiation effects on different GaN HEMT gate structures, highlighting the robustness of pGaN gates for space use.

Findings

pGaN gate devices exhibit stable threshold voltage under X-ray radiation

MIS gate devices show initial negative shift then positive shift in Vth

Radiation effects involve charge trapping and releasing in dielectric and interface layers

Abstract

Characteristic electrical curves of GaN HEMT devices from Infineon and Transphorm are compared at different X-ray radiation dose. It is shown that the device with pGaN gate is more robust having a stable threshold voltage (Vth). The Vth of device with MIS gate shifts towards negative direction firstly and shifts to forward direction then. A qualitative analysis is performed in the paper. Such dynamic phenomenon is caused by releasing and trapping effects of radiation induced charges both in the dielectric layer and the interface of the device. It is summarized that pGaN gate based GaN HEMT is a promising solution for further space use of electric source