Vacuum exhaust system and cleaning method

Abstract

A vacuum exhaust system is provided which can reduce consumption of a ClF gas for use in cleaning, and can shorten a cleaning time. An exhaust pipe from a dry pump to an abatement device is provided with a heater, thereby to be heated, so that the temperature of the exhaust pipe is set at a temperature exceeding 180° C. For the exhaust pipe, the pipe and a gasket of a sealing member are also made of a metal. Then, a ClF3 gas for cleaning is introduced. The ClF3 gas is activated at a temperature exceeding 180° C., and cleaning efficiency is remarkably enhanced. On the other hand, the gasket made of a metal is used. For this reason, even when the ClF3 gas is activated, a problem in sealing performance is less likely to be caused. For this reason, it is not necessary to wait until the temperature of the exhaust pipe becomes 180° C. or less, which enables shortening of the cleaning time.

Dependencies are inferred from the claim text.