X-RAY-SCATTERING RADIOGRAPHY AND ORIENTATION TOPOGRAPHY FOR CHARACTERIZATION OF SEMICONDUCTOR CRYSTALS

Scattering radiography is applicable for imperfect materials which cannot be observed by conventional X-ray diffraction topography. From an assembly of pixel data in scattering radiographs, we have extracted information on crystal orientation by a microcomputer to determine orientation distribution in the specimen. The method is named X-ray orientation topography, and its system capability has been demonstrated in observations of a lattice-mismatched InAs heteroepitaxial layer grown on a GaAs substrate by MBE. The apparatus constructed here has orientation and spatial resolution of 2.0 arc min and 48 μm, respectively. Orientation in the InAs epitaxial layer is found to vary over 18 arc min around 〈100〉, whereas a small lattice bending around 〈110〉 exists in the substrate of less than 2.0 arc min. © 1990.