The evolution of hollow-core defects in vapour-phase grown bulk crystals was investigated during subsequent liquid-phase epitaxial treatment. The hollow micro-defects were already found to decompose, into a number of micro-pipes, at supersaturations close to zero. The elimination of pure-screw dislocation-based micro-pipes required a higher supersaturation. The micro-pipes were observed to dissociate into individually acting non hollow-core dislocations. Following decomposition, the activity of growth centres based upon a micro-pipe was usually reduced and a new center could predominate at the growing surface. A model for the micro-pipe transformation mechanism was based upon BCF theory, and Chernov’s theory of morphological stability.

On the Mechanisms of Micropipe and Macrodefect Transformation in SiC during Liquid Phase Treatment. B.M.Epelbaum, D.Hofmann: Journal of Crystal Growth, 2001, 225[1], 1-5