The understanding of the properties of O impurities in Czochralski material was reviewed. Such atoms, which were present at concentrations of about 1018/cm3, occupied bond-centred sites (Oi) in as-grown samples, and the jump rate between adjacent sites defined so-called normal diffusion for temperatures of 1325-330C. High-temperature annealing led to the formation of amorphous SiO2 precipitates which acted as traps for fast-diffusing metallic contaminants, such as Fe and Cu, at levels as low as 1011/cm3. In order to accommodate local volume increases during O precipitation, there was an associated generation of self-interstitials which diffused away and formed lattice defects. Measurements of O diffusion into or out of the Si surface, and Oi aggregation, implied an enhancement of diffusion; that had been attributed to the interaction of Oi with lattice vacancies, self-interstitials, metallic elements, C or H impurities. There was strong evidence for O-H interaction up to 500C, and for the formation of fast-diffusing O2. Such observations had led to significant advances in the understanding of the growth and structure of small O clusters which were identified with so-called thermal donor and shallow thermal donor defects.

Oxygen Diffusion and Precipitation in Czochralski Silicon. R.C.Newman: Journal of Physics - Condensed Matter, 2000, 12[25], R335-65