The role of Frenkel defect diffusion in dynamic annealing in ion-irradiated Si Academic Article uri icon

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 140 °C with 500 keV Ar ions. Results reveal a defect relaxation time constant of ~10-0.2 ms, which decreases monotonically with increasing temperature. The dynamic annealing rate shows an Arrhenius dependence with two well-defined activation energies of 73 ± 5 meV and 420 ± 10 meV, below and above 60 °C, 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.

altmetric score

  • 7

author list (cited authors)

  • Wallace, J. B., Aji, L., Martin, A. A., Shin, S. J., Shao, L., & Kucheyev, S. O.

citation count

  • 9

publication date

  • May 2017