Electrical and physical properties of ion-doped GaAs layers obtained by Mg+ ion implantation

Electrophysical and recombination properties are studied in ion-doped layers obtained by Mg+ ion implantation (E=150 keV, D=5x1012-1x1016 ion/cm2, Timp=300 deg) into semi-insulting GaAs(Cr) with subsequent annealing at 500-100 deg for 10-30 min. It is found that for obtaining conducting p-layers the annealing at T >or approx. 500-600 deg is needed. Maximal values of the charge carrier surface concentration Ns are obtained at Tann=700-900 deg. A further increase of Tann leads to a decrease of N-s. The dopant utilization factor K ∼ 1 (K=Ns/D) is obtained for small D(≤1x1014 ion/cm2). The photoluminescence spectrum exhibits an intensive emission band at hv=1.46 eV caused by the implanted Mg