Effects of proton irradiation on dc characteristics of InAlN/GaN high electron mobility transistors

The effects of proton irradiation on the dc characteristics of InAlN/GaN high electron mobility transistors were investigated. In this study we used 5 MeV protons with doses varying from 2 x 10(11) to 2 x 10(15) cm(-2). The transfer resistance and contact resistivity suffered more degradation as compared to the sheet resistance. With irradiation at the highest dose of 2 x 10(15) cm(-2), both forward- and reverse-bias gate currents were increased after proton irradiation. A negative threshold-shift and reduction of the saturation drain current were also observed as a result of radiation-induced carrier scattering and carrier removal. Devices irradiated with doses of 2 x 10(11) to 2 x 10(15) cm(-2) exhibited minimal degradation of the saturation drain current and extrinsic transconductance. These results show that InAlN/GaN high electron mobility transistors are attractive for space-based applications when high-energy proton fluxes are present. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3644480]