EFFECT OF COMPETING TRAPPING CENTERS (SINKS) ON THE EVOLUTION OF IMPLANTED-NITROGEN DISTRIBUTION IN SILICON - A NUMERICAL-SIMULATION

Numerical simulation was used to show that the experimentally observed complex distribution of an implanted impurity is due to the appearanc e of several competing trapping centers (sinks) for mobile atoms. Thes e trapping centers lie near the maxima of the range and elastic loss d istributions, and also sinks that are initially present in the medium. The relative roles of the sinks are found to vary during implantation , which leads to the evolution of the impurity distribution. Experimen tal data on high-temperature implantation of N+ ions in silicon were f ound to be in good agreement with the evolution of the numerically sim ulated distributions, based on the existing information on the behavio r of nitrogen and defects in silicon. (C) 1996 American Institute of P hysics.