X-ray topography studies of microdefects in silicon

X-ray topography has been successfully applied to study microdefects with s izes in the range from well below standard topographic resolution to tenths of a mu m, thus effectively widening the applicability of Lang section top ography. The lower value is set by the application of high-order asymmetric reflections. The disappearance of the Kato fringes on section topographs i s a clear indication of the existence of defects which are not detectable a s standard contrast features. The presence of defects with such sizes was c onfirmed by transmission electron microscopy. Microdefects in the higher en d of the size spectrum are well covered by Lang traverse and section topogr aphy, where detailed study of the contrast is possible for individual defec ts. Lang traverse and section topographies were applied to study specific c ases of oxygen-related defects in silicon crystals.