Carbon enhancement effect on oxygen precipitation in Czochralski silicon

Publisher Website
Google Scholar
Abstract
The enhancement effect of carbon on oxygen precipitation in Czochralski (CZ) silicon has been investigated in detail by means of infrared (IR) absorption spectroscopy at room temperature. The critical temperature Tc, which distinguishes the two different ways in which carbon enhances oxygen precipitation, has been shown to exist between 800 and 850 °C. Perturbed [Ci-Oi]C(3) centers are observed by IR spectroscopy in the temperature range lower than the Tc. The perturbed C(3) center is estimated to consist of a complex with two to three oxygen atoms per carbon atom. It has moreover been confirmed that the carbon effect is explained in two ways: (i) carbon directly provides heterogeneous seeding sites, as [Ci-Oi]C(3) centers, for oxygen precipitation at temperatures lower than Tc; and (ii) carbon plays a catalytic role at temperatures higher than Tc. Finally, the formation of [Ci-Oi]C(3) centers is shown not to be affected by high-temperature preannealing at 1250 °C.