Optically detected magnetic resonance of a thermally induced deep center in electron-irradiated silicon

We report the investigation of a thermally induced deep level center (denoted as Si-X) in electron-irradiated silicon by optical detection of magnetic resonance (ODMR). This deep center was created after a heat treatment, at 400°C for a time longer than 60 min, in irradiated boron-doped silicon single crystals grown by both Czochralski and float-zone techniques. The symmetry of the Si-X center is determined to be trigonal, and the identity of the center is discussed in terms of a Si-related interstitial complex. The energy level for this center is argued to to be deep. This work shows that ODMR technique is capable of exploring strong nonradiative recombination channels in silicon, even when defects elude EPR detection due to their low concentrations, nonparamagnetic ground state, or short-lived excited states.