We have used electron paramagnetic resonance to study two intrinsic defects in oxidized epitaxial layers of 3C SiC, a potential substitute for Si in high speed, high power electronics. One center can be described by an isotropic g value of 2.0044. The defect is distinguished by a strong temperature dependence and is located throughout the 3C epitaxial layer. Although the detailed structure has not been determined, the g value is consistent with theoretical predictions for a Si dangling bond surrounded by carbon atoms. The second Si-related center, induced by post oxidation dry heat treatment, is characterized by an axial g tensor with g∥=2.0023 and g⊥=2.0082. The spectroscopic and chemical properties of the latter defect are consistent with those of the Si Pb center, a Si dangling bond located at a Si/insulator interface. Experiments show that in our 3C samples, the Pb signal is probably located on the Si side of a SiO2 /Si interface between the SiC epilayer and the Si substrate. © 2001 American Institute of Physics.
