Optically detected magnetic resonance studies of defects in 3C SiC epitaxial layers

Optically detected magnetic resonance (ODMR) was used to study defects in 3C SiC epitaxial layers grown at high temperatures (1550°C) by chemical vapour deposition on a free-standing 3C SiC film substrate. An isotropic, very broad and asymmetric ODMR line was observed under ultraviolet light excitation. This line is shown to be due to the overlapping of two different isotropic spectra, as revealed by magnetic field modulation measurements. Both spectra can be described by an effective electron spin S = 1 2 . The higher field line with a g-value of 2.006 may be related to a silicon vacancy. Using below bandgap excitation, the lower field spectrum (g = 2.012) was found to have a triplet structure which could be due to the hyperfine of 14N. This defect is related to a new photoluminescence band in the region of 1.1–1.58 eV.