Microdefects investigated by X-ray topography

The author describes recent results in the detection and study of as-grown microdefects in float-zoned (FZ) silicon single crystals by X-ray topographic methods. They show that plane-wave topography displays the highest sensitivity to slight displacement fields around the microdefects. The actual microdefect can be characterized through the comparison of the experimental topographs with its image simulated under the same diffraction conditions. It is thus possible to determine the type, nature, size, location and misfit volume of the microdefect. Another way to investigate microdefects is described, based on the study of microdefect dislocation activity by conventional methods of X-ray topography.