Electron paramagnetic resonance of radiation defects in hydrogen-implantedsilicon 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 mu m) o f silicon crystals are detected with spin-dependent microwave photoconducti vity. It is found that EPR spectra of the excited triplet states of oxygenvacancy complexes and spectra related to carbon-containing defects are form ed at low proton irradiation doses of about 2 x 10(12)-10(13) cm(-2). When the irradiation dose is increased from 10(13) to 5 x 10(13) cm(-2), a fast decrease of the intensity of the detected EPR spectra takes place. This eff ect is explained by passivation of the radiation defects by hydrogen. (C) 1 999 American Institute of Physics. [S0003-6951(99)03126-5].