Double Crystal Topography Compensating for the Strain in Processed Samples

Abstract

An extension of double crystal topography and -diffractometry is presented. The new technique is especially dedicated for defect characterization in samples strained from technological processing. Its basic idea is to account for the curvature in such samples by a crystal collimator of tunable curvature. The capacity of this “curved collimator topography” (CCT) in revealing dislocations as well as in analysing the composition of the mixed crystal layers is demonstrated with examples from Ga1−xAlxAs-double-hetero-epitaxy.