Strain relaxation in selectively grown ZnSe-epilayers on patterned GaAs-substrates

For the investigation of the strain relaxation in mesoscopic ZnSe structures selectively grown by MBE on patterned and unpatterned (001) GaAs substrates high-resolution X-ray diffraction was used. It is shown that the strain relaxation in the selectively grown structures with a thickness below about 500 nm is up to 9% higher than in the corresponding homogeneous layers. With increasing layer thickness the ratio of the relaxation is inverted, e.g. the relaxation is higher in the unpatterned layer. Reciprocal space mapping shows that the orientation distribution of the lattice net planes for the mesoscopic structures has a decreased width with respect to the unpatterned layers.