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

Abstract

This study examined the effects of three cumulative γ-ray irradiation doses on AlGaN/GaN epilayer material and on high electron mobility transistor (HEMT) devices. After a cumulative γ-ray dose of 16 kGy, the Hall mobility increased from 1800 cm2/V s to 2100 cm2/V s, as determined through Hall measurement. Atomic force microscopy indicated an improvement in surface roughness but no change in the surface potential $$ \left( {\emptyset_{\rm{s}} } \right) $$ . The HEMT device exhibited improvement in the drain current, with a subtle decreasing tendency in the leakage current. At high doses of γ-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.