Vacancies and Interstitials in Heat Treated Germanium

Abstract

Annealing experiments on the thermal acceptors quenched into germanium by rapid cooling from high temperatures are used to deduce information about vacancies and interstitials in germanium. Annealing is studied at a series of temperatures and a critical temperature is found at 516\ifmmode^\circ\else\textdegree\fi{}C. Above 516\ifmmode^\circ\else\textdegree\fi{}C, the annealing curves suggest a bimolecular recombination process implying that the heat treatment produces comparable numbers of vacancies and interstitials (Frenkel defects) which disappear by mutual annihilation. Below 516\ifmmode^\circ\else\textdegree\fi{}C, the data can be explained by a model in which interstitials are trapped near dislocations before much recombination can occur with vacancies. As a result of these experiments and their interpretation, interstitials are believed to be more mobile than vacancies below, and possibly above, 516\ifmmode^\circ\else\textdegree\fi{}C.