Low-Temperature, Solid-Phase Epitaxial Growth of Amorphized, Non-Stoichiometric GaAs

Abstract

AbstractNon-stoichiometric GaAs layers with semi-insulating properties can be produced by low-temperature molecular beam epitaxy or ion implantation. The latter is the subject of the present report wherein the solid-phase epitaxial growth of amorphized, non-stoichiometric GaAs layers has been investigated with time-resolved reflectivity, Rutherford backscattering spectrometry and transmission electron microscopy. GaAs substrates were implanted with Ga and/or As ions and annealed in air at a temperature of 260°C. The recrystallized material was composed of a thin, crystalline layer bordered by a thick, twinned layer. Non-stoichiometry results in a roughening of the amorphous/crystalline interface and the transformation from planar to non-planar regrowth. The onset of the transformation and the rate thereof can increase with an increase in non-stoichiometry. Non-stoichiometry can be achieved on a macroscopic scale via Ga or As implants or on a microscopic scale via Ga and As implants. The influence of the latter is greatest at low doses whilst the former dominates at high doses.