Solubilities and equilibrium distribution coefficients of oxygen and carbon in silicon

Abstract

Solubilities of oxygen and carbon in solid silicon at 1673 K were determined by using a chemical equilibrium technique. Solid silicon was heated at 1673 K in an oxygen atmosphere for 1800 ks, and then oxygen content in the solid silicon equilibrated with silica was measured by the inert gas fusion-IR absorption method. Carbon content in the solid silicon equilibrated with silicon carbide after heating at 1673 K in an Ar-5%CO atmosphere for 4860 ks was measured by the combustion-IR absorption method. Comparing these solubility values in solid silicon with those in liquid silicon that were previously reported by the present authors, the equilibrium distribution coefficients of oxygen and carbon in silicon at the melting point were evaluated to be 0.85 ± 0.08 and 0.30 ± 0.16, respectively.