Systematic Investigation of Interface Properties in 4H-SiC MOS Structures Prepared by Over-Oxidation of Ion-Implanted Substrates

摘要

A change in the interface state density in 4H-SiC metal-oxide-semiconductor (MOS) structures by incorporation of various elements was systematically investigated. B, N, F, Al, P, and Cl ions were implanted prior to the oxidation and introduced at the SiO_2/SiC interface by subsequent thermal oxidation. Interface state density near the conduction band edge for Al-, B-, F-, and Cl-implanted MOS capacitors increased with implantation dose. On the other hand, a strong reduction of the interface state density was observed for N- and P-implanted samples when the implantation dose was larger than 5.0 × 10~(12) cm~(-1). It was found that the interface state density can be reduced by P as well as N.