Evacuating unit with reduced diameter exhaust duct
AssigneeEbara Corporation
InventorsSatoshi Arai, Katsuaki Usui, Takahiro Isozaki
Life of this patent
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Abstract
An apparatus for and a method of evacuating a vacuum chamber (process chamber) or the like of a semiconductor fabrication facility, for example. The evacuating apparatus has a vacuum chamber to be evacuated, a discharge pipe connecting the vacuum chamber to an atmospheric port, a vacuum pump connected to the discharge pipe and operable at a variable rotational speed, and a controller for controlling the rotational speed of the vacuum pump.
Claims15
An apparatus for evacuating a vacuum chamber through a discharge pipe, comprising:
- a vacuum pump having a variable rotational speed;
- a controller for controlling the rotational speed of said vacuum pump to keep a back pressure on the vacuum pump in a predetermined target range;
- and
- a discharge pipe competing an outlet port of the vacuum pump to an atmospheric port and having a diameter corresponding to a specific flow capability in which said diameter is less than a predetermined diameter corresponding to an evacuating flow capability of the vacuum pump,
- wherein said predetermined target range is determined depending on the evacuating flow capability of the vacuum pump and a conductance of the discharge pipe.
A method of evacuating a vacuum chamber through a discharge pipe with a vacuum pump having a variable rotational speed, comprising:
- connecting a discharge pipe from an outlet port of the vacuum pump to the atmospheric port, said discharge pipe having a flow capability less than an evacuating flow capability of said vacuum pump;
- and
- controlling the rotational speed of said vacuum pump so as to keep the back pressure in a predetermined target range wherein said predetermined target range is determined depending on an evacuating flow capability of the vacuum pump and a conductance of the discharge pipe.
Dependencies are inferred from the claim text.