Process for preventing or removing deposits in the exhaust gas region of a vacuum installation

摘要

Method of avoiding or eliminating deposits in the exhaust area of a vacuum system in which a gas containing depositable constituents in the exhaust area is at least intermittently pumped out of a vacuum chamber that is connected to a vacuum pump via a gas line. A reactive gas that removes deposits from the gas in the vacuum pump and/or units provided downstream therefrom, and/or reduces or eliminates existing deposits in this area is at least intermittently added to the gas directly upstream from or within the vacuum pump. The proposed method is particularly suitable for anisotropic plasma etching of silicon using alternating etching steps and polymerization steps, the vacuum chamber being supplied with a sulfur-containing etching gas during the etching steps and a polymerizing agent-containing gas during the polymerization steps.