Orientation‐Dependent Nucleation and Propagation of Scratch‐Induced Dislocations in PVT‐Grown 4H‐SiC

ABSTRACT

Surface scratches on seed crystals are an important source of dislocation arrays during physical vapor transport (PVT) growth of 4H‐SiC and can directly affect the structural quality of electronic‐grade substrates. This work investigates how scratch orientation relative to the step‐flow direction governs the nucleation and subsequent propagation of scratch‐induced dislocations in PVT‐grown 4H‐SiC. X‐ray topography and molten KOH etching are combined to track the three‐dimensional evolution of defect arrays across sequential wafers. In addition, a phenomenological orientation factor based on anisotropic Hooke's law is introduced to compare the relative nucleation tendency along different in‐plane directions. The results show that the scratch angle is the key geometric parameter controlling defect evolution. In the low‐angle regime (0°, 40°), scratches mainly generate threading edge dislocation (TED)‐dominated arrays. In the intermediate regime (40°, 70°), mixed TED and basal plane dislocation (BPD) arrays are formed. In the high‐angle regime (70°, 90°), BPD‐dominated arrays are favored, and the BPDs glide laterally along the basal plane toward the crystal edge during growth. The measured lateral offset between TED and BPD arrays agrees well with the geometric prediction imposed by the 4° off‐cut configuration. These findings provide a practical guideline for scratch orientation management during seed preparation and offer a defect‐engineering strategy for improving the quality and manufacturability of 4H‐SiC substrates for power electronic applications.