Stacking faults induced high dielectric permittivity of SiC wires

We report that 3C-SiC wires with high stacking faults density exhibit higher permittivity in 2-18 GHz. Transmission electron microscopy suggests that the stacking faults were formed by embedding 2H-SiC segments in 3C-SiC matrix, which results in the formation of type-II 3C/2H-SiC heterostructures as both the valence-band maximum and the conduction-band minimum of 3C-SiC are lower than the corresponding positions of 2H-SiC. Plenty of interface dipoles are caused due to the charge separation occurs at the type-II heterointerface, and then the large dipole polarization loss is induced, which may be the main reason that causes the high dielectric permittivity of SiC wires. (C) 2013 AIP Publishing LLC.