Electrical Conductivity Improvement of Point Defects in 4H-SiC

Owing to its high melting temperature, the 4H-SiC substrate exhibits numerous defects that are difficult to remove, hindering the development of large-scale, high electrical conductivity 4H-SiC substrates. This study constructs and analyzes atomic models of point defects in 4H-SiC, focusing mainly on Si and C atom vacancies and interstitial defects. Point defects in 4H-SiC can increase the electrical conductivity. For example, the Si0 vacancy has been found to enhance the electrical conductivity of a 4H-SiC unit cell by more than 220 times, converting its wide bandgap property to metallic. The research demonstrates that defects can improve 4H-SiC properties, paving the way for defect-selective technology to develop large-scale, high electrical conductivity 4H-SiC substrates.