Spectroscopic Investigation of Light-Induced Degradation Paramagnetic Defect in Czochralski Silicon

We report on the electron paramagnetic resonance (EPR) spectra of Cz and FZ Si in different stages of light-induced degradation. Firstly, we show that the paramagnetic signal at low temperature (10K) is dependent on the state of light-induced degradation performed at room temperature and on the sample doping. The light-degraded state in p-CZ Si shows strong, sharp paramagnetic defect signatures compared to samples in the annealed state. When an excitation light is applied during the EPR measurement, additional structures appear in the spectra. In contrast, the wide EPR active signature related to boron interaction with lattice, is present in the annealed state but diminishes after light exposure. Finally, we show that the degraded paramagnetic signal returns when annealed samples are exposed to ambient light. We suggest that these changes in the electron paramagnetic resonance spectra is related to the boron-oxygen defect that causes light-induced degradation.