A model was presented for the formation mechanism of dislocation half-loop
arrays formed during the homo-epitaxial growth of 4H-SiC. The reorientation
during glide of originally screw oriented threading segments of basal plane
dislocation rendered them susceptible to conversion into sessile threading edge
dislocations, which subsequently pin the motion of the basal plane dislocation. Continued glide during further growth enables parts of the mobile basal plane
dislocation to escape through the surface leaving arrays of half loops comprising
two threading edge dislocations and a short basal plane dislocation segment with
significant edge component. The faulting behaviour of the arrays under UV
excitation was consistent with this model.
Nucleation Mechanism of Dislocation Half-Loop Arrays in 4H-Silicon Carbide
Homo-Epitaxial Layers. N.Zhang, Y.Chen, Y.Zhang, M.Dudley, R.E.Stahlbush:
Applied Physics Letters, 2009, 94[12], 122108