CURRENT-VOLTAGE AND CAPACITANCE-VOLTAGE CHARACTERISTICS OF METAL OXIDE/6H-SILICON CARBIDE STRUCTURE/

Current-voltage (C-V) and capacitance-voltage (C-V) characteristics of metal/SiO2/H-SiC structure fabricated on the concave surface in (000 (1) over bar)C-face 6H-SiC p/n double epitaxial wafers were studied. B reakdown field of thermally grown gate oxide and effective charge dens ity at SiO2/6H-SiC interface on sloped surface of the metal/ oxide/sem iconductor (MOS) structure were measured for the first time to be 9.2 MV/cm and 2.2-2.5 x 10(12) cm(-2) respectively, for both p- and n-epil ayers. Fabricated SiC CONCAVE-MOS field-effect-transistor (FET) includ ing the concave MOS structure achieved FET operation with blocking vol tage 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.