Electronic energy levels of defects that anneal in the 280-K stage in irradiated n-type gallium arsenide.

Abstract

Using optical-excitation minority-carrier deep-level transient spectroscopy we have studied the thermal annealing in n-GaAs of lattice-defect hole traps produced by 1.0-MeV proton irradiation at 120 K. We find that three hole traps, with electronic levels at 0.16 eV (of low concentration), at about 0.25 eV, and at 0.42 eV above the valence band, are removed in a thermal-annealing stage centered at about 280 K, consistent with the well known resistivity-annealing stage found at this temperature in electron-irradiated n-GaAs. This is the first determination of electronic energy levels of defects removed in the 280-K annealing stage of n-GaAs.