Lattice-mismatched InGaAs layers grown by OMVPE on GaAs based compliant substrates

Abstract

Thin GaAs compliant substrates have been developed in order to reduce the strain in lattice-mismatched layers during epitaxial overgrowth. Using OMVPE a variety of (30–80A) thin GaAs layers were grown and successfully fused at 660°C on a host GaAs substrate with twist-angles between 10° and 45°. The resulting compliant substrates were overgrown with up to 3.6% lattice-mismatched and 1200 nm thick InGaAs layers. Nomarski phase contrast microscopy, photoluminescence and x-ray diffraction (XRD) were used to characterize the heteroepitaxial layers. The smooth and cross-hatch free morphology and the reduced DXRD peakwidth of the heteroepitaxial layers indicate a substantial improvement of the quality of heteroepitaxial material using compliant substrates.