Influence of structural defects on lattice parameter and measured composition of Hg_1-xCd_xTe epilayers

摘要

Structural and compositional parameters of the Hg_1-xCd_xTe layers grown by metal-organic vapor deposition on (2 1 1)-oriented CdTe substrates were investigated by high-resolution X-ray diffraction, high-resolution scanning electron microscopy, energy dispersive spectroscopy in scanning electron microscopy and Fourier transform infra-red spectroscopy in a transmission mode. divergence in Cd concentrations, obtained by different methods, is explained in terms of extended defects which cause lattice swelling of the Hg_1-xCd_xTe matrix. Strong correlation between defect density and lattice swelling was established by absolute measurements of lattice parameters (Bond method) and by direct defect imaging. It is proposed to use high-resolution Bond technique for nondestructive monitoring of the layer quality. direct c 1999 Elsevier Science B.V. All rights reserved.