Susceptor effects on the morphological and impurity properties of 4H-SiC epilayers

The morphological and impurity properties of 4H-SiC epilayers grown using graphite susceptors coated with vitreous carbon, SiC, TaC, and NbC were compared. Metal carbide coated susceptors produced epilayers with smooth morphologies and no thick backside polycrystalline SiC deposition. Epilayers grown using metal carbide coated susceptors possessed more than 10 times higher intentional N-2 doping efficiencies and more than 10 times lower unintentional Al concentrations compared to epilayers grown using vitreous carbon coated susceptors. Metal carbide coated susceptors permitted doping control and abrupt p.n. junctions, and possessed more than 10 times longer lifetimes compared with vitreous carbon or SiC coated susceptors.