In situ observation of the Si melt–silica glass interface concerning CZ-Si crystal growth

An in situ observation was carried out for investigating the interfacial phase of so-called ‘brownish rings’ formed at the Si melt–silica glass interface concerning Czochralski (CZ) silicon crystal growth. It is found that some small dots appeared at the interface immediately after the Si melting, and grew gradually. The growth rate of the interfacial phase increases with increasing temperature, and it is almost the same when the silica dissolution rate is lower than a critical value. It can be concluded, therefore, that the growth rate of the interfacial phase does not depend on the silica dissolution rate in a practical CZ-Si crystal growth by considering that the silica dissolution rate in CZ-Si crystal growth is also lower than the critical value. Crystalline phase forms from the central region of the interfacial phase, and the amount of the crystalline phase increases with increasing temperature and reaction time.