X-ray diffraction from CuPt-ordered III-V ternary semiconductor alloy films

Abstract

A model has been developed to describe x-ray scattering from CuPt-type ordered III-V ternary semiconductor alloys. The model takes into account the size distribution of the two different laminae-shaped variants, the random distribution of antiphase domain boundaries in each variant, and the atomic displacements due to the bond-length difference between the two constitutive binary materials. A synchrotron x-ray source was employed to measure the weak-ordering reflections from CuPt-ordered ${\mathrm{Ga}}_{0.5}{\mathrm{In}}_{0.5}\mathrm{P}$ and ${\mathrm{Al}}_{0.5}{\mathrm{In}}_{0.5}\mathrm{As}$ samples. By comparing the experimental results and the model calculations, structure information, including the average number of atomic layers in the laminae of each variant, the average antiphase domain size, and the average order parameter in each variant, were obtained. Results from single-variant films and poorly ordered films are also discussed.