OPTICALLY DETECTED MAGNETIC-RESONANCE STUDIES OF DEFECTS IN ELECTRON-IRRADIATED 3C SIC LAYERS

Defects in electron-irradiated 3C SiC were studied by optically detect ed magnetic resonance (ODMR). In addition to the isotropic L2 center p reviously reported, an ODMR spectrum labeled L3, with a trigonal symme try and an effective electron spin S=1, was observed after annealing a t similar to 750 degrees C. The g values of the center along and perpe ndicular to the trigonal axis were determined as g(parallel to)=2.0041 and g(perpendicular to)=2.0040. The anisotropy of the spectrum is acc ounted 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 OD MR signal, the defect is found to be related to a photoluminescence ba nd 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.