Measurement of Lattice Strain Distribution of Striped Si0_2/GaAs Substrate by X-ray Double Crystal Method

摘要

Two measurement methods, slit-slide method and X-ray topography were applied to measure relative lattice strain distribution of striped SiO_2/GaAs. In the slit-slide method the fine distribution of the lattice strain was not detected. because X-ray beams through the slit of 26μm was too broad to focus on the area where the lattice strain varied abruptly. On the other hand X-ray topographs showed clear contrast which represents the lattice strain distribution. Each time X-ray incidence angle was increased or decreased by several second of arc from Bragg angle the topograph was taken. By comparing the contrast of these topographs, the lattice strain distribution was determined. The results shows that the strain distributes in narrow areas (about 10-μm width) along the borderline between d-stripe and r-stripe. The strain distributes in the narrow area along left and right borderlines of the d-stripe from +128" to -48"and from +56" to -128", respectively. The difference of the strain distribution between the left and the right border areas shows that the lattice planes in both border areas are tilted in opposite directions.