A series of measurements were performed in order to study the evolution of vacancy-type structures in silicon. Isothermal annealing performed during positron beam-based Doppler broadening measurements had yielded activation energies for vacancy cluster formation and evaporation in silicon of approximately 2.5 and 3.7eV, respectively. The clusters, which could predominantly be the stable hexavacancy, appeared to form between 400 and 500C, and anneal at ~600C. A similar technique applied to low-temperature in situ measurements had yielded the migration energies for the silicon monovacancy and interstitial (of ~ 0.5 and 0.08eV, respectively). Interesting observations of positronium formation at the surface of the samples studied during isothermal annealing were presented.

Activation Energies for Vacancy Migration, Clustering and Annealing in Silicon. P.G.Coleman: Journal of Physics - Conference Series, 2011, 265[1], 012001