Interaction between recombination enhanced dislocation glide process activated basal stacking faults and threading dislocations in 4H-silicon carbide epitaxial layers

Electron-hole recombination enhanced glide of Shockley partial dislocations bounding expanding stacking faults and their interactions with threading dislocations in 4H silicon carbide epitaxial layers have been studied using synchrotron white beam X-ray topography and in situ electroluminescence. The mobile silicon-core Shockley partial dislocations bounding the stacking faults are able to cut through threading edge dislocations leaving no trailing dislocation segments in their wake. However, when the Shockley partial dislocations interact with threading screw dislocations, trailing 30° partial dislocation dipoles are initially deposited in their wake due to the pinning effect of the threading screw dislocations. These dipoles spontaneously snap into their screw orientation, regardless the normally immobile carbon-core Shockley partial dislocation components in the dipoles. The subsequent cross slip and annihilation of screw oriented Shockley partial dipole leave a prismatic stacking fault in (2-1-10) plane with the displacement vector 1/3[01-10]. The formation of such prismatic stacking fault is energetically favorable, reducing the strain energy by one to two orders of magnitude.