Influence of the InP substrate deoxidization temperature on the growth of Zn 0.45Cd 0.55Se epilayers

Abstract

Zn 0.45Cd 0.55Se epilayers with lattice nearly matched to InP were grown at 360°C by metalorganic chemical vapor phase deposition. The influence of deoxidization temperature of the InP substrate, on the structural and optical properties and on the surface morphologies of the Zn 0.45Cd 0.55Se epilayer was investigated. With constant deoxidization duration of 10 min for each growth, the optimal deoxidization temperature was found to be around 480°C. Both too high and too low deoxidization temperatures cause a serious deterioration of the quality of epilayers by generating defects in the epilayers. Surface morphology studies showed that there are two types of structural defects, which are responsible for the reduced quality of the epilayers. For samples grown on InP deoxidized below the optimal temperature, high density of mound-like structures, as a result of 3D island growth and grain boundaries were found on the surface. While for samples grown on InP deoxidized at or above the optimal temperature, crater-like structures, which may be caused by In droplets formed during the deoxidization, were found on the surface.