Damage dependent electrical activation of phosphorus implanted in silicon

Damage profiles for 250-keV self-ion irradiation of gold, determined by (1) stereo electron microscopy measurements of the depth distribution of visible clusters and (2) binary-collision simulations, are presented. Simulations for an amorphous medium, a single crystal (with the ion beam oriented in a nonchanneling direction), and a polycrystal were performed using the MARLOWE code. The calculated damage profiles for the single crystal and the polycrystal both exhibit approximately exponential tails, but have shallower modal depths than the profile for the amorphous medium. The inclusion of room-temperature thermal vibrations in the simulations is found to broaden the profile and suppress long-range channeling. Comparison between simulation and experiment suggests that a screening length somewhat smaller than the Firsov value is appropriate for Au-Au interactions.