A review of the effects of proton, neutron, c-ray, and electron irradiation on GaN materials and devices is presented. Neutron irradiation tends to create disordered regions in the GaN, while the damage from the other forms of radiation is more typically point defects. In all cases, the damaged region contains carrier traps that reduce the mobility and conductivity of the GaN and at high enough doses, a significant degradation of device performance. GaN is several orders of magnitude more resistant to radiation damage than GaAs of similar doping concentrations. In terms of heterostructures, preliminary data suggests that the radiation hardness decreases in the order AlN/GaN > AlGaN/GaN > InAlN/GaN, consistent with the average bond strengths in the Al-based materials. V

A review of electron, proton and neutron damage in GaN and AlGaN materials and devices such as high electron mobility transistors and lightemitting diodes is presented. A comparison of theoretical and experimental threshold displacement energies is given, along with a summary of energy levels introduced by different forms of radiation, carrier removal rates and role of existing defects. Many studies have shown that GaN is several orders of magnitude more resistant to radiation damage than GaAs, i.e., it can withstand radiation doses at least two orders of magnitude higher than those degrading GaAs of similar doping level. In terms of heterostructures, the initial data suggests that the radiation hardness decreases in the order AlN/GaN >AlGaN/GaN > InAlN/GaN, consistent with the average bond strengths in the Al-based materials. Many issues still have to be addressed. Among them are the strong asymmetry in carrier removal rates in n-and p-type GaN and interaction of radiation defects with Mg acceptors, and the poor understanding of the interaction of radiation defects in doped nitrides with the dislocations always present.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

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