Dislocations in 4H silicon carbide. (23rd September 2022) - Li, Jiajun
Abstract: Owing to the superior properties of the wide bandgap, high carrier mobility, high thermal conductivity and high stability, 4H silicon carbide (4H-SiC) holds great promise for applications in electrical vehicles, 5G communications, and new-energy systems. Although the industrialization of 150 mm 4H-SiC substrates and epitaxial layers has been successfully achieved, the existence of a high density of dislocations is one of the most severe bottlenecks for advancing the performance and reliability of 4H-SiC based high-power and high-frequency electronics. In this topical review, the classification and basic properties of dislocations in 4H-SiC are introduced. The generation, evolution, and annihilation of dislocations during the single-crystal growth of 4H-SiC boules, the processing of 4H-SiC wafers, as well as the homoepitaxy of 4H-SiC layers are systematically reviewed. The characterization and discrimination of dislocations in 4H-SiC are presented. The effect of dislocations on the electronic and optical properties of 4H-SiC wafers and epitaxial layers, as well as the role of dislocations on the performance and reliability of 4H-SiC based power devices are finally presented. This topical review provides insight into the fundamentals and evolution of dislocations in 4H-SiC, and is expected to provide inspiration for further control of dislocations in 4H-SiC.