Electron paramagnetic resonance of radiation defects in hydrogen-implanted silicon detected by spin-dependent microwave photoconductivity

Electron paramagnetic resonance (EPR) spectra of radiation defects induced by low-energy protons (100 keV) in a thin near-surface layer (L<1 μm) of silicon crystals are detected with spin-dependent microwave photoconductivity. It is found that EPR spectra of the excited triplet states of oxygen+vacancy complexes and spectra related to carbon-containing defects are formed at low proton irradiation doses of about 2×1012–1013 cm−2. When the irradiation dose is increased from 1013 to 5×1013 cm−2, a fast decrease of the intensity of the detected EPR spectra takes place. This effect is explained by passivation of the radiation defects by hydrogen.