Neutron irradiation effects in AlGaN/GaN heterojunctions

It is shown that in neutron-irradiated undoped n-AlGaN/GaN heterojunctions, the mobility and sheet conductivity start to decrease only after exposure to doses higher than 1015 cm-2. The effects on mobility are mostly due to the introduction of additional scattering centers in the GaN buffer layer of the structures while there are only slight changes in the two-dimensional electron concentration. Electron traps with activation energy of 0.21, 0.35 and 0.45 eV were observed in the AlGaN barrier, hole traps with energies of 0.18, 0.2, 0.26, 0.7 and 1 eV were detected and could be located either in the AlGaN barrier or in the GaN buffer