A study was made of the non-destructive determination of dislocation type and Burgers vector direction in GaN using electron channelling contrast imaging inside a scanning electron microscope. Fore-scattered electron intensity fluctuations generated by threading dislocations exhibited characteristic spatial profiles indicative of dislocation type (screw, edge) and Burgers vector direction. Simulated channelling contrast features by two-beam dynamic diffraction calculations showed qualitative agreement with recorded images. The fore-scatter electron channelling contrast imaging sensitivity to atomic steps and low-angle grain boundaries in GaN allowed for additional confirmation.
Resolving the Burgers Vector for Individual GaN Dislocations by Electron Channeling Contrast Imaging. Y.N.Picard, M.E.Twigg, J.D.Caldwell, C.R.Eddy, M.A.Mastro, R.T.Holm: Scripta Materialia, 2009, 61, 773-6