STRUCTURAL AND OPTICAL CHARACTERIZATION OF IMPLANTED AND ANNEALED SEMIINSULATING GAAS

The structural and optical properties of SI GaAs crystals implanted with Se, Si and Be ions have been studied. The implanted fluences ranged from 10(12) to 10(15) cm-2 at energies of 2.3 MeV (Be), 7 MeV (Si) and 10.9 MeV (Se), producing buried damaged layers centered at a depth of about 3 mum. Changes in the lattice constant were measured by XRD and the corresponding strain and damage profiles were determined and correlated with estimates of damage obtained from the results of channeling-RBS measurements. Both photolumineSCence and Raman measurements were used to probe the damage as a function of depth with the aid of a shallow bevel produced by chemical etching. All measurements indicate a maximum of damage around 3 mum. Except for a region at the end of range, the crystal structure of p+ Be-doped GaAs has recovered its original quality upon annealing.