SEMIINSULATING GAAS MADE BY AS IMPLANTATION AND THERMAL ANNEALING

We have demonstrated that it is possible to regrow amorphous layers cr eated by high dose As implantation in GaAs by thermal annealing in ord er to obtain arsenic precipitates distributed in a GaAs matrix similar ly to that observed in low temperature GaAs. The characteristics of th e As precipitates can be monitored through appropriate selection of th e implantation and annealing conditions. Electrical measurements show that dielectric-like resistivity of surface or buried GaAs lavers can be obtained by this method. Results on the growth of epilayers on thes e semi-insulating regions are also reported.