Heteroepitaxial growth of InP and GaInAs on GaAs substrates using nonhydride sources

Abstract

The heteroepitaxial growth of InP and Ga0471n053 As on GaAs substrates have been investigated by using tertiarybutylarsine (TBA) and tertiarybutylphosphine (TBP) as group V sources. The group III sources are ethyldimethylindium (EDMIn) and triethylgallium (TEGa). The growth process was carried out in a hydrogen flow in a horizontal reactor, where the substrates were placed on a radiatively heated, silicon carbide-coated graphite plate. Heteroepitaxial InP layers with mirror smooth surfaces were deposited on GaAs substrates using a two temperature growth process under atmospheric pressure: a buffer layer was deposited at 400°C followed by the deposition of an epitaxial layer at 500°-550°C. InP layers deposited without intentional doping are n-type with a net electron concentration of (2-3) x 1016 cm3. The FWHM of the excitonic peak of the 4.2 K photoluminescence of an InP layer of 1.1 m thickness is 5.2 meV. Heteroepitaxial Ga0471n053As layers were also deposited on GaAs substrates by the two temperature growth process under reduced pressure using an InP or a Ga0471n053As buffer layer grown at 400°C and the subsequent epitaxial growth at 5OOO 550°C. The composition of the GaInAs layers was determined by x-ray diffraction, photoluminescence, and optical absorption measurements. As-grown surfaces of Ga0471n053As layers of about 2 j&m thickness are visually featureless; however, dislocation density on the order of 108 cm2 was observed by chemical etching and SEM examinations.