Generation of misfit dislocations due to thermally induced strain - a study by temperature-dependent HRXRD

Thermally induced strain is used to induce plastic strain relaxation in a 2 80 nm thick ZnSe layer grown on a GaAs substrate. Changes in the crystallin e quality in dependence on temperature an investigated in situ by high-reso lution X-ray diffraction. Reciprocal space maps and triple-axis rocking cur ves are performed to measure the diffuse scattered intensity around the ZnS e Bragg peak. A striking change in the diffuse scattering is observed when heating the sample above growth temperature up to 600 K. From the diffuse s cattered intensity the misfit dislocation density in the as-grown and the t hermally treated layer is estimated to be 2 x 10(3) and (1-2)x 10(4) cm(-1) , respectively. These results are in agreement with dislocation densities e stimated from the lateral lattice mismatch. (C) 2000 Elsevier Science B.V. All rights reserved.