RELATIONSHIP BETWEEN DIFFERENT INTERFACIAL PHASES AND OXYGEN SOLUBILITY IN SILICON MELT

Different interfacial phases formed at the interface between undoped o r Sb-doped Si melt and SiO2 were observed, and the relationship betwee n the interfacial phases and oxygen solubility in the Si melts was inv estigated. A foil-form interfacial phase with composition of about SiO 1.8 appeared between the bulk Si melt and SiO2 ampule wall when the Sb concentration in the Si melt was less than 0.5 at%. However, the from of the interfacial phase became dendritic and composition changed to SiO2 when the Sb concentration was in the range from 0.5 to 2.0 at%. T he interfacial phase disappeared when the Sb concentration reached abo ut 2.0 at%. Corresponding to the different interfacial phases, the equ ilibrium oxygen concentrations in the Si melt also changed considerabl y, i.e., from 2 x 10(18) at/cm3 to about 2 x 10(19) at/cm3.