UNUSUAL STRAIN IN HOMOEPITAXIAL CDTE(001) LAYERS GROWN BY MOLECULAR-BEAM EPITAXY

For homoepitaxial CdTe(001) films grown by molecular beam epitaxy onto CdTe(001) substrates, a difference between the lattice constants of t he substrate and the layer was systematically observed using high reso lution X-ray diffraction. Reciprocal space maps point out an unusual s train state of such layers which is indicated by the position of their reciprocal lattice points. They lie in a section of reciprocal space which is usually forbidden by elasticity theory. The strain is lateral ly anisotropic leading to a monoclinic symmetry of the thin films. The lateral strain is depth dependent. Possible reasons for the formation of the unusual strain are discussed, and a correlation of the unusual strain with the growth conditions is attempted.