The role of Frenkel defect diffusion in dynamic annealing in ion-irradiated Si.
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
The formation of stable radiation damage in crystalline solids often proceeds via complex dynamic annealing processes, involving migration and interaction of ballistically-generated point defects. The dominant dynamic annealing processes, however, remain unknown even for crystalline Si. Here, we use a pulsed ion beam method to study defect dynamics in Si bombarded in the temperature range from -20 to 140C with 500keV Ar ions. Results reveal a defect relaxation time constant of ~10-0.2ms, which decreases monotonically with increasing temperature. The dynamic annealing rate shows an Arrhenius dependence with two well-defined activation energies of 735meV and 42010meV, below and above 60C, respectively. Rate theory modeling, bench-marked against this data, suggests a crucial role of both vacancy and interstitial diffusion, with the dynamic annealing rate limited by the migration and interaction of vacancies.