Advances and challenges in 4H silicon carbide: defects and impurities

Under the impetus of global carbon peak and carbon neutrality goals, a new generation of semiconductor material is urgently needed in various aspects of power electronic systems. In comparison to traditional semiconductor materials like single-crystal silicon, the outstanding characteristics of 4H silicon carbide (4H-SiC) have gradually positioned it as a crucial semiconductor material for emerging power semiconductor applications. Attributed to the significance of impurities and defects in the semiconductor, profound and in-depth comprehension of impurities and defects about 4H-SiC plays a crucial guiding role. This paper, building upon a brief overview of the current state of 4H-SiC research, summarizes the experimental and theoretical advancements in the study of defects and impurities about 4H-SiC in recent years. Besides, we also systematically review the categories of defects in 4H-SiC, introduce methods for characterizing and identifying defects in 4H-SiC, and thoroughly discuss potential doping technologies in 4H-SiC. Challenges faced in the research of defects and impurities are finally outlined.