X-ray characterization of 3 inch diameter 4H and 6H-SiC experimental wafers

Experimental 3 inch diameter 4H and 6H SiC wafers have been examined using synchrotron white beam x-ray topography, x-ray peak position mapping, and KOH etching. Topographic images of the wafer show dark lines of orientation contrast associated with the presence of small angle boundaries that have a radial distribution around the wafers' highly contrasted central regions. Misorientations associated with the boundaries were measured by high-resolution diffraction mapping be on the order of 500 arcsec, and to be either a pure tilt type with rotation axis in the basal plane or mixed tilt and twist. KOH etching provided further evidence for the types of dislocations associated with these boundaries.