Eighteen mega-electron-volt alpha-particle damage in homoepitaxial β-Ga2O3 Schottky rectifiers

Abstract

Homoepitaxial Ga2O3 rectifiers with vertical geometry were subject to 18 MeV alpha particle irradiation at fluences of 1012–1013 cm−2, simulating space radiation exposure. The range of these particles (∼80 μm) is much greater than the drift layer thickness in the structures (∼7 μm). The carrier removal rates were in the range of 406–728 cm−1 for these conditions. These values are factors of 2–3 higher than for high energy (10 MeV) protons and 2 orders of magnitude higher than for 1.5 MeV electron irradiation of the same material. The on-state resistance of the rectifiers is more degraded by alpha particle irradiation than either ideality factor or barrier height. The reverse breakdown voltage of the rectifiers increases with alpha particle dose as carriers in the drift region are removed by trapping into traps created by the radiation damage. The on/off ratio of the rectifiers was severely degraded by alpha particle-induced damage, but the reverse recovery characteristics were unaffected even by the highest dose, with values around ∼20 ns.