Lattice mismatched molecular beam epitaxy on compliant GaAs/Al xO y/GaAs substrates produced by lateral wet oxidation

Abstract

Large-area 16 nm GaAs–Al x O y –GaAs substrates were formed by lateral wet oxidation of patterned GaAs/Al 0.97Ga 0.03As/GaAs heterostructures. Wet digital etching followed by in situ dry iodine etching was used to prepare thin GaAs layers intended to serve as compliant substrates. Relaxed layers of In 0.15Ga 0.85As were deposited on the compliant substrates and on bulk GaAs substrates using In 0.15Ga 0.85As and In 0.15Al 0.85As nucleation layers. The In 0.15Ga 0.85As epitaxial layers grown on the compliant substrates using an In 0.15Al 0.85As nucleation layer showed no crosshatch pattern by Nomarski microscopy and had X-ray rocking curve linewidths that were narrower than those grown on bulk GaAs or on samples with In 0.15Ga 0.85As nucleation layers.