Current-Voltage and Capacitance-Voltage Characteristics of Metal/Oxide/6H-Silicon Carbide Structure

Abstract

Current-voltage ( I-V ) and capacitance-voltage ( C-V ) characteristics of metal/ SiO 2 /6H-SiC structure fabricated on the concave surface in (0001̄)C-face 6H-SiC p/n double epitaxial wafers were studied. Breakdown field of thermally grown gate oxide and effective charge density at SiO 2 /6H-SiC interface on sloped surface of the metal/oxide/semiconductor (MOS) structure were measured for the first time to be 9.2 MV/cm and 2.2-2.5×10 12 cm -2 , respectively, for both p- and n-epilayers. Fabricated SiC CONCAVE-MOS field-effect-transistor (FET) including the concave MOS structure achieved FET operation with blocking voltage of 250 V. Temperature dependence of the threshold voltage was -27 mV/K, which is considerably larger than the ideal value of -1.6 mV/K, due to high interface state density.