High-geometrical-resolution imaging of dislocations in SiC using monochromatic synchrotron topography

We demonstrate high-geometrical-resolution imaging of dislocations in 4H-SiC by monochromatic synchrotron topography (but still under the "integrated wave" condition). In back-reflection topographs, 1c screw dislocation images are "magnified" to appear as well-defined circular white spots, while basal plane dislocations with opposite edge Burgers vector components exhibit two distinct kinds of contrast features. All the dislocation images are precisely described by ray-tracing simulations. This imaging technique provides an accurate, comprehensive, and nondestructive characterization tool, which is needed by current SiC researchers is used for industrial applications. It also provides a simple picture for understanding the mechanisms underlying synchrotron diffraction imaging of defects.