Abstract
X‐ray topography has been applied to cleaved cross sections of 
and 
wafers. Experimental procedures for cleavage face x‐ray topography are described in this paper, and the wide range of use for this method is shown. Using this technique a measure of the depth of damage introduced into the material during cutting and polishing, as well as during device fabrication, e.g., the application of ohmic contacts, is obtained. The relative defect density in 
substrates and epitaxial layers can be determined from the topographs. Damage introduced at the substrate‐epitaxial layer interface can also be readily identified.