Direct mass spectrometric identification of silicon oxychloride compounds

Silicon oxychloride compounds formed during the high temperature reaction of Si and SiC with Cl2/O2 mixtures at 930 and 950 C have been directly observed with an atmospheric pressure mass spectrometer sampling system. Molecules with the formulas Si2OCl6 and Si3OCl8 have been identified. These compounds are very likely formed by a gas phase reaction between the oxygen gas in the system and silicon tetrachloride which is produced by chlorination of the silicon-based material.