Energy levels of carbon dangling-bond center (PbC center) at 4H-SiC(0001)/SiO2 interface

Abstract

The electric properties of the carbon dangling-bond (PbC) center at a thermally oxidized 4H-SiC(0001)/SiO2 interface are investigated. We experimentally and theoretically determine the energy levels of the associated interface states to estimate the impacts of the PbC center on power device operations. By combining electrically detected magnetic resonance spectroscopy and capacitance–voltage measurements, the two PbC electronic levels [(0/−) and (+/0)] are determined as ∼1.2 and 0.6 eV from the valence band maximum, respectively. The effective correlation energy of the PbC center is 0.6 eV, which is 1.5 times larger than that of the silicon dangling-bond (Pb) center at Si/SiO2 interfaces. Our first-principles calculations confirm that the electronic levels of PbC are similar to experimental values. Considering these energy levels, the PbC center must impact both p- and n-channel devices, which is closely related to previously reported channel features.