VACUUM SYSTEM AND METHOD FOR OPERATING SAME

摘要

Provided is a vacuum system wherein the rotating speed of a vacuum pump can be suitably adjusted at the time of performing prescribed process in a vacuum chamber to contribute to energy saving. A vacuum pump controller (33) in a semiconductor manufacturing system (10) is provided with gas flow mode and auto-tuning mode. In the auto-tuning mode, the rotating speed of a vacuum pump unit (30) is determined so that an operation quantity of an APC valve (22) is at a target value within a range which is less than the full operation quantity by a prescribed quantity, in a status where the inside of a process chamber (21) is in a vacuum required in the gas flow mode. The vacuum pump controller is provided with a means for judging whether the operation quantity of the APC valve (22) reached the target value or not, by reducing the rotating speed of the vacuum pump unit (30) from a rated speed, in a status where the inside of the process chamber (21) is in the vacuum required in the gas flow mode, for operation in the auto-tuning mode; and a means for storing the rotating speed of the vacuum pump unit (30) as a rotating speed in the gas flow mode when it is judged that the operation quantity reached the target value.