Crystalline structure of heteroepitaxial GaAs and GaAsP layers grown on GaAs substrates investigated by X-ray diffraction. 2. Strain in GaAsP layer

Following our previous paper, the crystalline structure of GaAs/GaAsP layers, used for spin-polarized electron sources, was investigated by X-ray diffraction. From the observation of reciprocal maps of the {113} reflections under the condition of a small glancing angle with a narrow receiving slit, the strain remaining in the GaAsP layer was revealed. The strain remained only along the [1-bar10] direction; however, strain in a long range was almost released along the [1-bar1-bar0] direction. It was also shown that the specimen was divided into four large blocks, with their boundaries being parallel to the [1-bar1-bar0] and [1-bar10] directions. At the boundary parallel to the [1-bar1-bar0] direction, the {113} lattice plane was distorted. (author)