The elucidation of the structure of semiconductor multilayers can be a
dequately determined by x-ray methods but the interpretation is not al
ways straightforward. In this paper we introduce the idea of full thre
e-dimensional diffraction-space mapping to obtain information on the t
hree-dimensional structure of imperfect materials. We also stress the
importance of this method for the interpretation of the data from high
-resolution x-ray diffractometry. The presence of defects and diffract
ion effects can create significant changes to the diffraction pattern
that require a more complete analysis than that obtained from simple p
rofiles. These subtle influences can in general only be understood by
diffraction-space mapping. interpretation of diffraction-space maps fr
om the high-resolution multiple-crystal multiple-reflection diffractom
eter permits the use of three extra very powerful tools. The first is
multiple-crystal topography so that the diffraction-space intensity fe
atures can be related to lateral contrast on the photographic emulsion
, the second is the accurate determination of lattice parameters and t
he third is the simulation of the diffraction shapes using dynamical t
heory.