Section topographs of edge and screw dislocations with an axis along [00▪1] in 6H-SiC were taken, and the image formation was explained. The contrast induced by various arrangements of dislocations within the Borrmann triangle was experimentally studied. The sign of the Burgers vector of an edge or screw dislocation normal to the crystal surface was shown to be unambiguously determined from the section-topograph image of this dislocation. The sign of the Burgers vector of a screw dislocation could also be determined from its image taken with Lang projection topography. The contribution of a long-range strain field to the section images of edge and screw dislocations normal to the crystal surface was revealed. The experimental contrasts recorded using section topography and Borrmann-effect-based topography were compared.

Section Images of Dislocations Normal to the Surface of a 6H-SiC Single Crystal. A.O.Okunev, L.N.Danilchuk, V.A.Tkal: Physics of the Solid State, 2006, 48[11], 2084-90