Process for working up the residual gases obtained in the deposition of silicon and in the conversion of silicon tetrachloride

US4454104A · kind A · utility

Assignee

• Wacker-Chemitronic Gesellschaft fur Elektronik Grundstoffe mbH · DE

Inventors

• Rudolf Griesshammer · Altötting, DE
• Franz Koppl · Altötting, DE
• Helmut Lorenz · Burghausen, DE
• Friedrich Steudten · Burghausen, DE

Key dates

• Filing date: Aug 4, 1982
• Grant date: Jun 12, 1984
• Expiry date: Aug 4, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B33/1071
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The chlorosilanes contained in the residual gases obtained in the deposit of silicon and in the conversion of silicon tetrachloride are first condensed out in liquid form. The hydrogen chloride present in the residual gases is dissolved in the condensed silicon tetrachloride. The remaining, virtually pure hydrogen is passed back into the process. During the distillation of the condensate, the dissolved hydrogen chloride is removed and can be separated off and reused. The trichlorosilane obtained after the distillation and the silicon tetrachloride can also be reused in the deposition process or the conversion process, respectively.