Influence of structural defects on lattice parameter and measured composition of Hg1-xCdxTe epilayers

Structural and compositional parameters of the Hg1-xCdxTe layers grown by m etal-organic vapor deposition on (2 1 1)-oriented CdTe substrates were inve stigated by high-resolution X-ray diffraction, high-resolution scanning ele ctron microscopy, energy dispersive spectroscopy in scanning electron micro scopy and Fourier transform infra-red spectroscopy in a transmission mode. Divergence in Cd concentrations, obtained by different methods, is explaine d in terms of extended defects which cause lattice swelling of the Hg1-xCdx Te matrix. Strong correlation between defect density and lattice swelling w as established by absolute measurements of lattice parameters (Bond method) and by direct defect imaging. It is proposed to use high-resolution Bond t echnique for nondestructive monitoring of the layer quality. (C) 1999 Elsev ier Science B.V. All rights reserved.