Influence of buffer layer thickness and epilayer’s growth temperature on crystalline quality of InAs0.6P0.4/InP grown by LP-MOCVD

InAs0.6P0.4 epilayers grown on InP (100) substrates using two-step growth method by LP-MOCVD were investigated. A low temperature (450 °C) In0.18Ga0.82As buffer layer was introduced to relax the lattice mismatch between the InAs0.6P0.4 epilayer and the InP substrate. The influence of In0.18Ga0.82As buffer layer thickness and epilayer’s growth temperature on crystalline quality of InAs0.6P0.4 epilayer was characterized by Scanning electron microscopy, X-ray diffraction, Hall measurements, Transmission electron microscopy and Photoluminescence. The experimental results showed that the crystalline quality of InAs0.6P0.4 epilayers could be greatly improved by optimizing the In0.82Ga0.18As buffer layer thicknesses and the InAs0.6P0.4 epilayer’s growth temperatures. It was found that, when In0.82Ga0.18As buffer layer thickness was 100 nm and InAs0.6P0.4 epilayer’s growth temperature was 580 °C, the InAs0.6P0.4 epilayer exhibited the best crystalline quality and properties.

► InAs0.6P0.4 materials have been prepared by two-step growth method.
► The quality of InAs0.6P0.4 can be improved with a 100 nm InGaAs buffer layer.
► The quality of InAs0.6P0.4 can be improved when epilayer is grown at 530 °C.
► The optimum experimental conditions of preparing InAs0.6P0.4 have been obtained.