Partial dislocations in the X-ray topography of as-grown hexagonal silicon carbide crystals

Dislocations visible in X-ray topographs of as-grown hexagonal silicon carbide Lely platelets and physical vapor transport process wafers extinguished as if they had Burgers vectors of 1/3〈112̄0〉. Under the electron microscope, beneath the resolution of X-ray topography, short lengths of these dislocations were shown to consist of pairs of 1/3〈101̄0〉 Shockley partials spanning narrow ribbons of stacking fault. An unusual example of a b=1/3〈112̄0〉 dislocation in a Lely platelet visibly separated into its partials in an X-ray topograph was presented.