Synchrotron Radiation Imaging Observation with Extremely Small Exit Angle for Lattice Mismatched Semiconductor Epitaxial

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We develop X-ray scattering topography system, which is capable for observing a semiconductor epitaxial layer with sub-micron laterally spatial resolution using synchrotron radiation. The scattering topography system proposed by us with sub-micron laterally spatial resolution have a main component of a straight micro pinhole device. We have demonstrated observation for dislocations in Si, Ge, GaAs etc. bulk samples, and obtained valuable information which has never gotten by other characterization method. We had never reached better observation for epitaxial film than bulk one. We are going to try characterization of X-ray diffraction optical geometry at around critical angle with controlling of X-ray penetration depth.Silicon wafer specimens with different surface nanotopography patterns, as measured by optical measurements, and different boron concentrations, were characterized by a grazing incident diffraction (GID) topography and total reflection imaging method near the critical an … More gle using plane-waves. We used plane-waves produced by the high-resolution diffraction topography station located at the medium-length (200 m) bending-magnet beam line at BL20B2 of SPring-8. The GID topographs and total reflection images gave qualitative and detailed information on the dependence of surface roughness on boron doping concentration. Moreover, grazing incident X-ray diffraction is based on the new technique called in-plane diffraction measurement. GaN epitaxial layer grown by plasma-assisted molecular beam epitaxy on GaAs (001) substrate. Using the in-plane diffraction measurement, we could obtain significant information concerning to GaN growth mechanism. The hexagonal (wurtzite) phase often co-exists with cubic (zinc blende) one for two-polymorphs (wurtzite and zinc-blend structures). Incident angle dependence of GaN epitaxial layer for in plane 2θ_χ/φ-scannning diffraction intensity (a) zincblende-GaN, (b) wurtzite-GaN, critical angle ω_c is 0.206° for CuKα_1. While the lattice spacing for GaN_<zinc blende> || have a dependence of depth, that for GaN_<wurtzite> crystal have no depth dependence. Less