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 ∼750 °C. The g values of the center along and perpendicular to the trigonal axis were determined as ${\mathrm{g}}_{\mathrm{\parallel }}$ =2.0041 and ${\mathrm{g}}_{\mathrm{\perp }}$ =2.0040. The anisotropy of the spectrum is accounted for by the spin-spin interaction with a crystal-field splitting value D=4.2×${10}^{\mathrm{-}2}$ ${\mathrm{cm}}^{\mathrm{-}1}$ . 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.