Measuring properties of point defects by electron microscopy: The Ga vacancy in GaAs

Abstract

Exploiting the high spatial resolution and sensitivity of chemical mapping, we measure the intermixing in a series of microscopic marker layers imbedded in GaAs to detect the passage of Ga vacancies injected at the surface before the steady state has been reached. We thus deduce each of the formation and migration enthalpies for the Ga vacancy under technologically relevant conditions. More generally, we show how multilayers may be used as microscopic laboratories to investigate the properties of intrinsic point defects in solids.