It was recalled that it had previously been concluded that the O-precipitate associated defects that were linked to deep levels at Ev + 0.30eV and Ec - 0.25eV were the Pb centres which were generated in the interfaces between O precipitates and the surrounding Si lattice. In order to confirm this, electron spin resonance measurements were carried out on Czochralski-grown Si crystals which contained O precipitates that were generated by 2-step annealing (500C, 20h, 700C, 60h). It was found that the electron spin resonance lines agreed well with those of Pb0 and Pb1 centres. It was thus confirmed that the Pb0 and Pb1 centres were generated by O precipitation as well as by thermal oxidation.

Electron Spin Resonance Centres Associated with Oxygen Precipitates in Czochralski Silicon Crystals. M.Koizuka, H.Yamada-Kaneta: Journal of Applied Physics, 2000, 88[4], 1784-7