Molecular beam epitaxial growth of InP using a valved phosphorus cracker cell: optimization of electrical, optical and surface morphology characteristics

Abstract

We report the molecular beam epitaxial (MBE) growth of epitaxial InP using a valved phosphorous cracker cell at a range of cracking zone temperature (T/sub cr/=875/spl deg/C to 950/spl deg/C), V/III flux ratio (V/III=1.2 to 9.3) and substrate temperature (T/sub s/=360/spl deg/C to 500/spl deg/C). The as-grown epitaxial InP on InP [100] substrate was found to be n-type from Hall measurements. The background electron concentration and mobility exhibited a pronounced dependence on the cracking zone temperature, V/III flux ratio and substrate temperature. Using a cracking zone temperature of 850/spl deg/C, the highest 77 K electron mobility of 40900 cm/sup 2//Vs was achieved at a V/III ratio of 2.3 at substrate temperature (T/sub s/) of 440/spl deg/C. The corresponding background electron concentration was 1.74/spl times/10/sup 15/ cm/sup -3/. The photoluminescence (PL) spectra showed two prominent peaks at 1.384 eV and 1.415 eV, with the intensity of the low energy peak becoming stronger at higher cracking zone temperatures. The lowest PL FWHM achieved at 5 K was 5.2 meV.