Dresden 2014 – wissenschaftliches Programm

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MI: Fachverband Mikrosonden

MI 7: Synchrotron Radiation (Focus Session with Accelerator Physics)

MI 7.2: Hauptvortrag

Mittwoch, 2. April 2014, 15:30–16:00, MOL 213

Progress in White Beam Diffraction Imaging — •Andreas Danilewsky — Kristallographie, Universität Freiburg, Freiburg

Monochromatic X-ray diffraction imaging (topography) has been used for over half a century for the characterization of extended defects such as dislocations, slip bands, stacking faults, etc. in single crystals and devices fabricated thereupon. The advantage of using the synchrotron white beam is a Laue pattern of reflections on X-ray sensitive film, each containing a topograph from the same sample volume. It allows a fast Burgers vector analysis, even in case of high dislocation densities and in high absorbing crystals. The actual development of fast and high resolving indirect digital detector systems supports a tremendous reduction of the exposure time for a single diffraction image. Integration times of less than 0.2 s allow e.g. the real-time metrology of 450 mm Si wafers in less than 4 hours or the in-situ topography at high temperatures to analyse dislocation dynamics in Si or GaAs. A very promising new development is the 3-dimensional diffraction imaging. It results from the 3-dimensional rendering of a high number of section transmission topographs across the sample with the beam collimated to 15 µm and a step size of 15 µm. This new approach allows the measurement of the absolute strain value around defects.