Optically detected magnetic resonance studies of defects in electron-irradiated 3C SiC layers

Defects in electron-irradiated 3C SiC were studied by optically detected magnetic resonance (ODMR). In addition to the isotropic L2 center previously reported, an ODMR spectrum labeled L3, with a trigonal symmetry and an effective electron spin S=1, was observed after annealing at similar to 750 degrees C. The g values of the center along and perpendicular to the trigonal axis were determined as g(parallel to)=2.0041 and g(perpendicular to)=2.0040. The anisotropy of the spectrum is accounted for by the spin-spin interaction with a crystal-field splitting value D=4.2X10(-2) cm(-1). From a spectral dependence study of the ODMR signal, the defect is found to be related to a photoluminescence band in the near midgap region. The defect is likely a complex involving a silicon vacancy and another intrinsic defect as suggested from its trigonal symmetry and annealing behavior.