Photoluminescence study of the defects induced by neutron irradiation and rapid annealing in semi-insulating GaAs

The rapid annealing behavior of several kinds of defects in semi-insulating GaAs irradiated with various neutron fluences has been characterized using a photoluminescence technique. In this experiment, transmutation impuritie s form not only donors, but also acceptors, Ge-As (the 1.4783 eV peak). The intensity ratio of the 1.4783 eV peak (Ge-As) to the 1.4917 eV peak (C-As) increases with the neutron dose. This finding is consistent with the expec ted increase of Ge-As produced by transmutation. We also see that short tim e heat treatment leads to the increase of antisite defects Ga-As and of com plex centers I-Ga-V-As after neutron irradiation. Based on analysis of the rapid annealing process in comparison with the regular annealing process, i t is concluded that the two kinds of defects Ga-As and I-Ga-V-As are the pr oducts of defect reactions during the annealing process. (C) 1999 American Institute of Physics. [S0021-8979(99)02614-6].