Epilayer-substrate interfaces of Ge-doped GaAs grown by liquid-phase epitaxy

Abstract

The interfaces between Ge-doped GaAs homoepitaxial layers grown by liquid-phase epitaxy and their semi-insulating substrates have been characterized by photoluminescence and charge-carrier transport measurements. Our data suggest that a portion of the thermally generated As vacancies in the immediate vicinity of the interface are occupied by Ge atoms; this leads to a reduction in the deep-level complexes attributed to CAs–VAs associated with the thermally induced degradation of the substrate surface prior to epitaxial growth.