Analysis of Threading Edge Dislocation Low-Angle Grain Boundary Network Distributions in 4H-SiC Wafers Through Synchrotron X-ray Topography and Ray-Tracing Simulation

Analysis of a distinct threading edge dislocation (TED) low-angle grain boundary (LAGB) network is carried out on physical vapor transport (PVT)-grown off-axis 4H-SiC wafers through synchrotron x-ray topography in conjunction with ray-tracing simulation. The frequently observed white contrast main TED LAGB network distributed approximately along the [112¯0] offcut direction away from the facet, as well as dark contrast satellite TED LAGB networks on either side of the main TED network, is explained with a horseshoe-shaped growth step model induced by radial temperature gradient-related diffusivity variation with screw-oriented prismatic slip dislocations as the dislocation source. The significant effective tilt aroused by the TED LAGB network is quantitatively determined through a mathematical model.