Fig. 101: X-ray diffraction Moiré topograph of a sample produced in a standard SIMOX process. Wavelength = 0.40 Å, 022-reflection (diffraction vector parallel to the horizontal image border). The distance between the Moiré fringes is 3 µm, which leads to relative deformations of about 10-7. The small points visible on the topograph are images of threading dislocation pairs in the thin silicon layer. Dislocation density is about 4 x 104 cm-2