Misfit and threading dislocations in (Cd,Hg)Te epitaxial layers which had been grown on (111)B CdTe or (Cd,Zn)Te substrates, by means of liquid-phase epitaxy, were studied by using etching techniques. In the case of (Cd,Hg)Te/CdTe heterojunctions, the misfit dislocations which were introduced during the initial stages of epitaxial growth moved in [111]-type directions and redistributed so as to accommodate the mismatch strain due to the compositional gradient which was caused by Hg and Cd interdiffusion. In the case of (Cd,Hg)Te/(Cd,Zn)Te heterojunctions, the misfit dislocations were pinned by Zn out-diffusion from the substrate. With a suitable ZnTe fraction in the substrate, the linear dislocation pit density on cleaved and etched (¯110) surfaces was equal to only 1% of the equivalent figure for a CdTe substrate. It was noted that the density of dislocations which threaded into the epitaxial layer was not determined by the degree of lattice mismatch, but by the dislocation density of the substrate.

M.Yoshikawa: Journal of Applied Physics, 1988, 63[5], 1533-40