Effects of Proton-Induced Displacement Damage on Gallium Nitrided Power Amplifier RF Performance

Abstract

High frequency RF and microwave communications systems for military, space, and telecommunications applications require efficient power amplifiers with high power density. Gallium nitride high electron mobility transistors (GaN HEMTs) are a top contender for use in these applications due to the superior material properties of GaN. GaN HEMTs are extremely tolerant to ionizing radiation, but unexplained failure mechanisms and reliability concerns exist for GaN HEMTs in radiation environments. In this work, we investigate the effects of proton-induced displacement damage on circuit level RF parameters such as gain, stability, power output, and mode of operation of the amplifier circuit, and relate these effects to the device-level degradation of the GaN HEMT. Commercial-off-the-shelf GaN HEMTs from two leading manufacturers were evaluated and a comparison of the radiation response between the two HEMTs is given, along with discussion of the physical mechanisms. Suggestions to mitigate the negative effects of displacement damage on GaN HEMTs are also provided.