A threading dislocation in 4H-SiC, which was interpreted as being a right-handed threading screw dislocation by synchrotron monochromatic-beam X-ray topography and molten KOH etching with Na2O2 additive (KN etching), was characterized by large-angle convergent-beam electron diffraction and weak-beam dark-field methods. It was found that this threading dislocation was a so-called c+a dislocation with Burgers vector of b = [00•1] + (1/3)[21•0], which was often misinterpreted as being a threading screw dislocation (c-dislocation) by synchrotron monochromatic-beam X-ray topography and KN etching. The rotation direction of the screw component within the c+a threading dislocation determined by large-angle convergent-beam electron diffraction agreed with the synchrotron monochromatic-beam X-ray topography observations.

Transmission Electron Microscopy Analysis of a Threading Dislocation with c+a Burgers Vector in 4H-SiC. Y.Sugawara, M.Nakamori, Y.Z.Yao, Y.Ishikawa, K.Danno, H.Suzuki, T.Bessho, S.Yamaguchi, K.Nishikawa, Y.Ikuhara: Applied Physics Express, 2012, 5[8], 081301