Investigation of X‐ray Satellite Reflections Attributed to Antiphase Boundaries in Epitaxial (Ga,In)P Layers grown on (001) GaAs Substrates

We report on the analysis of additional X‐ray reflections that probably arise from antiphase domain boundaries within (Ga,In)P/(001) GaAs heteroepitaxial layers. Due to the preferred cation ordering along the crystallographic directions 1‐1 1] and ‐1 1 1] which belong to the 110] zone the original sphalerite‐type structure of (Ga,In)P changes into a CuPt‐like of the cation sublattice. This ordering phenomenon causes a loss of symmetry, i.e. the cubic structure is converted into a rhombohedral one. The antiphase boundaries between ordered domains are assumed to behave similar to lattice planes at X‐ray diffraction. Therefore, additional reflections may occur spatially neighboured to the 001] direction. The presented results of X‐ray experiments are discussed in relation to TEM experiments published in the literature in order to explain the origin of the satellite reflections. In the case of the investigated samples (grown on GaAs substrates misoriented 2° towards the azimuthal 010] direction) the APBs run preferentially in directions tilted up to angles of 20° with respect to growth direction. A preferential occurrence of satellite reflections in <13 2 1> directions was observed coinciding with {13 2 1} "lattice planes" whose normals enclose the same angle to the 001] growth direction as the normals of the average planes characterized by APBs. The appearence of the phenomenon in other directions that are also spatially neighboured to the <13 2 1> directions was determined on the basis of the shift of the reflection positions due to tilting the sample around an axis geometrically included in the scattering plane.