Growth of Ga xIn 1− xAs/InP thin layer structures by chemical beam epitaxy

Abstract

Multiple layer structures of InP and Ga x In 1− x As have been grown on InP substrates by chemical beam epitaxy (CBE). The samples were analyzed by photoluminescence (PL) spectroscopy at 5 K, double-crystal X-ray diffraction (DCXRD) and transmission electron microscopy (TEM). From 2000 Å thick layers, the PL measurements revealed the variation of the composition as a function of growth temperature. The influence of the growth interruption sequence (GIS) on the interfacial layers of 10-period superlattices with a 20 Å Ga 0.47In 0.53As well and a 40 Å InP barrier is investigated. The time responsible for the exchange of P by As atoms at the “lower” ( InP → Ga 0.47 In 0.53 As) interface is varied from 0 to 10 s at a growth temperature of 525°C. A minimal PL linewidth was observed for 1 s. TEM analysis showed abrupt transitions and a period thickness of 61 ± 3 Å. Both simulation of DCXRD measurements and calculation of PL transition energies revealed the formation of minimally 1 ML InAs y P 1− y during the substitution at the “lower” interface.