Due to the superior properties of wide bandgap, high carrier mobility, high thermal conductivity, and high stability, 4H silicon carbide (4H-SiC) has demonstrated significant application potential in the realm of high-power electronic devices, high-frequency electronic devices, and quantum information technology. 4H-SiC single crystals can be grown by top-seeded solution growth (TSSG), high-temperature chemical vapor deposition (HTCVD), and physical vapor transport (PVT). Among these technologies, the PVT technology has been widely applicated because of its high maturity, sensitive temperature tunability, low-cost raw material, etc. The industrialization application of 6-inch 4H-SiC single crystal grown by using the PVT technology has been achieved. 

Power electronic devices based on 4H-SiC homoepitaxial thin films have been booming in the realm of new energy technologies, smart grids, rail transit, etc. However, the dislocation density in commercial 6-inch 4H-SiC single crystal substrates is still as high as 10 3 ~ 10 4 cm – 2. Such high-density dislocations extend to the epitaxial layer or transform into other types of dislocation or stacking faults (SFs) during homoepitaxy. That the dislocations in 4H-SiC epitaxial layers act as carrier recombination centers reduces the minority carrier lifetime and increase the leakage current, which is one of the most severe bottlenecks limiting the application of 4H-SiC. Therefore, understanding the basic properties of dislocations in 4H-SiC and the generation, transformation, and annihilation mechanism of dislocations during the single crystal growth of 4H-SiC, the processing of 4H-SiC wafers, and homoepitaxy of 4H-SiC, is crucial to reducing the dislocation density and regulating the properties of 4H-SiC.