Nitrogen Ion Implantation into α-SiC Epitaxial Layers

Abstract

N+ implantation into p-type α-SiC (6H-SiC, 4H-SiC) epilayers at room and elevated temperatures, mainly obtained by the authors' group, has been reviewed. Since recrystallization of SiC is difficult, the implantation-induced damage should be minimal during implantation to achieve higher electrical activation. The effects of hot implantation are pronounced in high-dose (>1015 cm—2) implantation. The lowest sheet resistance of 542 Ω/□ was obtained by implantation at 500 to 800 °C with a 4 × 1015cm—2 dose. The properties of pn junctions formed by N+ implantation into p-type epilayers are characterized in detail. The forward current is clearly divided into two components of diffusion and recombination currents. The diodes exhibited high breakdown voltages of 615 to 820 V, which are almost ideal values expected from device structure. The reverse leakage current can significantly be reduced by employing hot implantation at 800 °C.