Crystal growth of high quality hybrid GaAs heteroepitaxial layers on Si substrate by metalorganic chemical vapor deposition and liquid phase epitaxy

Abstract

This paper reports the first successful liquid-phase epitaxial (LPE) growth of hybrid GaAs from a Bi solvent for the starting growth temperature (SGT) of 650°C on GaAs coated Si grown by metalorganic chemical vapor deposition (MOCVD) without oxide strip windows. The hybrid-grown GaAs on Si has shown better crystallinity than the MOCVD-grown one. The quality of the grown layers has been characterized by photoluminescence (PL), double-crystal X-ray diffraction (XRD) and etch pit density (EPD). The PL intensity increased nearly twice and the full-width at half-maximum (FWHM) of the double-crystal XRD is reduced to 125 arcsec after the growth of GaAs layers by LPE. The dislocation density was about 7 times lower than the dislocation density observed in the MOCVD GaAs on Si layer which served as a substrate for the LPE growth. The cross-sectional view was observed by scanning electron microscope (SEM) and transmission electron micrograph (TEM). The TEM results indicate that the high dislocation density has drastically reduced in the LPE layer.