Lattice imaging study of in-depth disordering of Si-implanted GaAs

Cross-sectional high resolution transmission electron microscopy has been used to obtain direct information on the in-depth radiation damage distribution of weakly damaged GaAs by Si-ion implantation. A comparison is made between the experimental data and the calculated (using TRIM computer simulations) deposited energy by nuclear stopping for the same conditions. In particular a diffusion zone, with 200–300 Å width, of high point defect concentration beyond the damage peak is detected. These point defects are interpreted as As interstitials. By direct observation, information concerning the damage- and radiation-enhanced diffusion in implanted III–V compound semiconductors is obtained.