Effects of gamma-Ray Irradiation on AlGaN/GaN Heterostructures and High Electron Mobility Transistor Devices

Abstract

This study examined the effects of three cumulative c-ray irradiation doses on AlGaN/GaN epilayer material and on high electron mobility transistor (HEMT) devices. After a cumulative gamma-ray dose of 16 kGy, the Hall mobility increased from 1800 cm(2)/V s to 2100 cm(2)/V s, as determined through Hall measurement. Atomic force microscopy indicated an improvement in surface roughness but no change in the surface potential (theta(s)). The HEMT device exhibited improvement in the drain current, with a subtle decreasing tendency in the leakage current. At high doses of gamma-ray irradiation, the trends in the material and device parameters saturated. Moreover, the metal-semiconductor interface degraded, as confirmed through scanning electron microscopy image analysis.