Heteroepitaxy of GaAs on Si and Ge by low-Energy ion Beam Deposition Using Alternating Beams

Abstract

ABSTRACTIn this paper, we demonstrate the growth of heteroepitaxial thin films of GaAs at low temperatures on Si(100) and Ge(100) substrates by direct deposition from controlled, low-energy (30-50 eV), mass-separated beams of 69Ga+ and 75As+ ions. This represents the first use of two fully ionized beams for the growth of compound semiconductor thin films. Mixing of the constituents was accomplished by periodically switching tile analyzing magnet to alternate between deposition of Ga and As at approximately monolayer intervals. Ion channeling and transmission electron microscopy show that GaAs films grown on Ge substrates at 400°C are free of the microtwins and stacking fault defects which emanate from the interface of GaAs similarly grown on Si. Single-crystal GaAs films with ion channeling minimum yields of around 6% have been grown on Ge(100) substrates at temperatures from 520°C down to as low as 320°C.