The effect of graphite components and crucible coating on the behaviour of carbon and oxygen in multicrystalline silicon

Growth under a CO enriched atmosphere is associated with the formation of a SiC/SiO2 melt surface layer, which pins the carbon concentration in the melt or crystal near its solubility limit, whereas in graphite- or CO-free growth the dissolved carbon segregates approximately according to Scheil's law. On the other hand, the effect of carbon monoxide on oxygen concentration in the grown crystals appears to be negligible. Instead, the oxygen concentration is directly related to the oxygen content of the crucible coating.