Dependence on the Schottky metal and crystal orientation of the Schottky diode characteristics of β-SiC single crystals grown by chemical vapor deposition

Abstract

Schottky barrier contacts have been made on β-SiC single crystals grown by chemical vapor deposition on Si substrates, and their capacitance-voltage and current-voltage characteristics are measured. Dependence of the Schottky characteristics on Si substrate orientation [(n11), n=6, 5, 4, 3, 1, and (100)] is examined. The current-voltage characteristics of the Schottky diodes of the β-SiC films on Si(611) and Si(411) are excellent compared with the conventional Schottky diodes on Si(100). The barrier height is determined by the pulsed capacitance-voltage method. Capacitance-voltage characteristics are measured by this method avoiding the effects of deep levels which are not ionized at room temperature. The dependence on the Schottky metal (Pt and Au) is examined. Both Pt-Schottky diodes and Au-Schottky diodes show good rectification characteristics. The barrier height of the Pt-Schottky diodes is 1.3–1.8 eV and that of the Au-Schottky diodes 1.0–1.6 eV, depending on the substrate orientation. For the same substrate orientation the barrier height for Pt is found to be 0.1–0.3 eV larger than that for Au.