It was argued that micropipes, in SiC crystals grown by using the physical vapor transport process, formed independently of screw dislocations. A mechanism which involved liquid droplets of Si containing some C or graphite particles was proposed in order to explain the formation of micropipes. The observed strain fields which were associated with micropipes were attributed to the presence of screw dislocations in their vicinity. An expression was developed that related the change in radius of a micropipe to the number of screw dislocations that was eliminated during its expansion.

Origins of Micropipes in SiC Crystals. S.Mahajan: Applied Physics Letters, 2002, 80[23], 4321-3