Reciprocal space mapping of implanted A IIIB V semiconductor compounds

Abstract

The reciprocal space maps around the 400 reciprocal space point were collected for a number of different implantations in GaAs and Al x Ga 1− x As including high dose implantations (∼10 16 ions/cm 2) with 1.5 MeV Se + and As + ions. We also studied the effect of high pressure annealing in GaAs implanted with 170 keV protons. The maps were recorded from an area of 50×100 μm 2 with a very good resolution of details. The maps usually revealed the same sequence of interference maxima as the double crystal rocking curves recorded with a widely open detector slit. This series of maxima was also well reproduced in numerically calculated theoretical rocking curves. The maxima were usually located exactly along the central θ/2 θ scan. In one case we observed a deviation of the interference maxima from the θ/2 θ direction, connected with lateral strain changes and consequent tilt deformation of the lattice. The maps for as implanted layers did not reveal significant diffuse scattering. A significant increase of diffuse scattering was present in proton implanted GaAs after thermal annealing performed at 450 °C under 11 kbar of argon pressure for a sample implanted with 170 keV protons with a dose 2·10 16 cm −2.