MICRODEFECTS INVESTIGATED BY X-RAY TOPOGRAPHY

We describe recent results in the detection and study of as-grown micr odefects in float-zoned (FZ) silicon single crystals by x-ray topograp hic methods. They show that plane-wave topography displays the highest sensitivity to slight displacement fields around the microdefects. Th e actual microdefect can be characterized through the comparison of th e experimental topographs with its image simulated under the same diff raction conditions. It is thus possible to determine the type, nature, size, location and misfit volume of the microdefect. The advantages o f synchrotron radiation for the investigation of microdefects are disc ussed. Another way to investigate microdefects is described, based on the study of microdefect dislocation activity by conventional methods of x-ray topography.