REGROWTH OF THE PHOTOQUENCHABLE DEFECT RELATING TO THE HOPPING CONDUCTION IN ARSENIC-ION-IMPLANTED SEMIINSULATING GAAS

The quenching phenomenon in Mott-type hopping conduction below 125 K h as been observed in Asi-ion-implanted semi-insulating GaAs. The crysta llinity of the implanted layer was evaluated using Rutherford backscat tering and Raman scattering methods. The hopping conduction was observ ed in the as-implanted and annealed samples. The as-implanted layer wa s amorphous, while the annealed layers remained crystalline, consistin g of a disordered structure with a displacement fraction of similar to 10(21) cm(-3). In the samples annealed at 500 degrees C, it is sugges ted that some of the As precipitates are located on Ga sites, leading to the disappearance of the Al a Raman active mode of the As clusters. The hopping conduction was photoquenched as the defect concentration reached similar to 6 x 10(17) cm(-3), indicating the regrowth of the A S(Ga) antisite defects as a main component of EL2. (C) 1996 American I nstitute of Physics.