High-voltage 4H-SiC pn diodes fabricated by p-type ion implantation

We formed a low-resistance p region by high-dose aluminum (Al) ion implantation in the 4H-SiC (0001) face, and fabricated and characterized planar pn diodes by Al or boron (B) ion implantation. In Al ion implantation, the minimum sheet resistance of 3.6 kOmega/rectangle (p-type) is obtained by high-temperature implantation and high-temperature annealing. Excellent rectification was verified in planar pn diodes, in which the surface p(+) layer was formed by high-temperature implantation of Al ions and the p layer was formed by room-temperature implantation of high-energy B ions. We achieved a high blocking voltage of 2900 V (90% of the theoretical withstand voltage), a low on-resistance of 8.0 mOmegacm(2), and avalanche breakdown characteristics of a positive temperature coefficient for the blocking voltage. We fabricated a 4H-SiC (11 (2) over bar0) pn diode, which has not been disclosed previously, and obtained a high blocking voltage of 1850 V (70% of the theoretical blocking voltage). (C) 2003 Wiley Periodicals, Inc.