Bragg Diffraction Imaging of CdZnTe Single Crystals

A high-quality CdZnTe single crystal has been imaged with micrometer resolution using monochromatic x-ray Bragg diffraction at the bending magnet (BM)-05 beamline of the European Synchrotron Radiation Facility. Since this material is used to produce substrates for the epitaxial growth of infrared sensitive HgCdTe photon detectors, imaging the defects is of strong interest to visualize their arrangement within the bulk. We show that large field-of-view rocking curve projection maps can be acquired in transmission geometry using samples as thick as 0.5 mm thanks to the Borrmann effect. Furthermore, section topography can be applied to provide information on the depth of the observed defects allowing for a complete 3D localization of lattice distortions. Examples of 1.5 mm x 1.5 mm full width at half-maximum maps are given to illustrate the spatial arrangement of dislocations in a number of samples cut with respect to different crystallographic planes in a particular CdZnTe ingot.