James T Fowler

US Patent:

40924467, May 30, 1978

Filed:

Jul 31, 1974

Appl. No.:

5/494005

Inventors:

Francois A. Padovani - Dallas TX
Michael Brant Miller - Richardson TX
James A. Moore - Dallas TX
James H. Fowler - Plano TX
Malcolm Neville June - Plano TX
James D. Matthews - Denver CO
T. R. Morton - Denver CO
Norbert A. Stotko - Denver CO
Lewis B. Palmer - Denver CO

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

C01B 3300

US Classification:

427213

Abstract:

A balanced closed cycle silicon refinery has been developed for producing electronic silicon from industrial grade silicon. Impurities comprising approximately 1% of the industrial grade silicon are removed during the refinery process to produce the purified silicon, while only a relatively small percentage of make-up chemicals are added to the system. In the refinery, hydrogen chloride is reacted with the impure silicon in a halide reactor to provide trichlorosilane and silicon tetrachloride and hydrogen. The trichlorosilane and/or silicon tetrachloride are purified to remove the impurities, and then reacted with the hydrogen from the halide reactor in a fluidized bed reactor to produce the purified silicon and an effluent comprised of unreacted trichlorosilane, silicon tetrachloride, hydrogen, and the by-product hydrogen chloride. These materials are separated and the trichlorosilane and silicon tetrachloride and hydrogen are returned to the silicon reactor while the hydrogen chloride is returned to the halide reactor to be reacted with additional industrial grade silicon in a closed cycle process.