A new technique for the detection of structural defects in SiC bulk crystals

Structural defects in sublimation sandwich grown SiC wafers of a large area have been studied with diffraction, absorption and phase contrast imaging techniques by using highly parallel X-ray flux. The contrast appeared due to either tilt, strain or density gradients between a matrix and a defect. Coherence properties of hard X-ray beams of third-generation synchrotron radiation sources such as the ESRF, were utilized to produce phase contrast in a free-space propagation mode. The nature of the observed defects has been confirmed by scanning electron and optical microscopy data.