Changes of defect and active-dopant concentrations induced by annealing of highly Si-doped GaAs

Abstract

We identified point defects and dopant atoms and measured their concentrations in as-grown and post-growth annealed highly Si-doped GaAs by scanning tunneling microscopy. The annealing under As atmosphere reduces the concentration of Si atoms incorporated into Si pairs and clusters by cluster dissolution, while the concentrations of Si donors, Si donor--Ga vacancy complexes, and Si donor--As vacancy complexes increase. For the dissolution of the Si clusters during heat treatment, a Ga-vacancy-mediated mechanism is suggested.