DEFECT ANNEALING OF ALPHA-PARTICLE IRRADIATED N-GAAS

The annealing behaviour of irradiation induced defects in n-type GaAs irradiated at 300 K with 5.4 MeV alpha-particles from an americium-241 (Am-241) radio nuclide have been investigated. The annealing kinetics are presented for the alpha-particle induced defects Ealpha1-Ealpha5 detected in Organo-Metallic Vapor Phase Epitaxially (OMVPE) grown n-GaAs doped with silicon to 1.2 x 10(16) cm-3, these kinetics are compared to those obtained for similar defects (E1-E5) detected after electron irradiation. While defects Palpha1 and Palpha2 were detected after removal of the electron defects Ealpha4 and Ealpha5, respectively, a new defect labelled Palpha0, located 0.152 eV below the conduction band, was introduced by annealing. The thermal behaviour and trap characteristics of these three defects (Palpha0-Palpha2) are presented. In an attempt to further characterise defects Palpha0 and Palpha1 a preliminary study investigating the emission rate field dependence of these defects was conducted, it was observed that defect Palpha0 exhibited a fairly strong field dependence while Palpha1 exhibited a much weaker dependence.