Dislocations in 4H-SiC epilayers for power devices: Identification, formation, and regulation

4H-SiC is highly promising for modern electronics, particularly in high-temperature, high-frequency, and high-power applications. However, the presence of dislocations in 4H-SiC epilayers significantly affects the performance and reliability of 4H-SiC-based power devices, thus limiting their widespread application. This review provides an overview of the classification, fundamental properties, and inspection methods of dislocations in 4H-SiC epilayers. The mechanisms of dislocation nucleation, propagation, and conversion during epitaxial growth are presented. Furthermore, strategies to mitigate dislocations, with a particular focus on enhancing the efficiency of BPD-TED conversion, are comprehensively discussed. By offering insights into dislocation behavior in 4H-SiC epilayers, this review highlights the challenges and emerging directions in the study of dislocations.