Hemlock Semiconductor Corporation

Robert G Brink

Kimmai Thi Nguyen

Guy Leo Reggio

Michael H Greene

David M Muller

Norman H Deitering

A process for determining the organoamines concentrations in chlorosilane. The process comprises separating a mixture comprising as a major portion a chlorosilane and as minor portion an organoamine having a boiling point less than or about the boiling point of the chlorosilane, where the organoamine is complexed in situ in the chlorosilane to form an organoamine complex which vaporizes at a temperature greater than the boiling point temperature of the chlorosilane, into a vapor phase comprising the chlorosilane and a solid phase comprising the organoamine complex. An aqueous solution of the solid phase is formed and analyzed by ion exchange chromatography for organoamine content. The present invention is particularly useful for analyzing chlorosilanes for dimethylamine and trimethylamine where the chlorosilane or residual hydrogen chloride in the chlorosilane serves to complex the organoamine.

Method for determining organoamines concentrations in chlorosilane

The present invention relates to a method for the purification of tetrachlorosilane used for the manufacture of electronic grade silicon and, more particularly, to a method for removing trace impurities of phosphorus. The method involves contacting liquid tetrachlorosilane with activated charcoal. The process is effective in reducing the phosphorus levels in the tetrachlorosilane to the parts per trillion range. The process can be run as a continuous or batch process with easy separation of the activated charcoal. containing the phosphorus contaminate from the tetrachlorosilane.

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St. Louis, MO, United States of America

Robert G Brink