Effects of Nitrogen Doping on the Morphology of Basal Plane Dislocations in 4H-SiC Epilayers

Morphologies of BPDs in 4H-SiC epilayers with different nitrogen doping concentrations are explained in detail. While BPDs in low-doped epilayers have the typical morphology of gliding dislocations responding to stress, BPDs in highly doped ([N]≥1.0×1018 cm-3) epilayers are straight and tilt away from [11-20]. Structures of BPDs are further studied by weak-beam TEM.