Air cleaning apparatus used for an exposure apparatus
AssigneeNikon Corporation
InventorsShigeru Hagiwara, Noriaki Tokuda
Life of this patent
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Abstract
A chemical filter for removing a chemical impurity is arranged at an air inlet, and a gas sensor for adsorbing the chemical impurity is arranged upstream of the chemical filter. The service life of the chemical filter is determined on the basis of the resonance frequency of the gas sensor. Alternatively, the chemical filter has a specific portion whose removal capacity for the chemical impurity is lower than that of the rest, and a sensor for sensing the chemical impurity is arranged downstream of the specific portion. The service life of the chemical filter is predicted on the basis of an output from the sensor.
Claims11
A gas cleaning apparatus comprising:
- a filter unit for removing a chemical substance from a gas;
- an adsorbing member arranged upstream and apart from said filter unit, in relation to a flowing direction of the gas, to adsorb a sample of the chemical substance from the gas before the gas enters the filter unit;
- and
- a determination unit for measuring an amount of the adsorbed chemical substance and determining a service life of said filter unit based on the measured amount of the adsorbed chemical substance.
An exposure apparatus comprising:
- a filter unit for removing a chemical substance from a gas circulated in a chamber;
- an adsorbing member arranged upstream and apart from said filter unit, in relation to a flowing direction of the gas, to adsorb a sample of the chemical substance from the gas before the gas enters the filter unit;
- and
- a determination unit for measuring an amount of the adsorbed chemical substance and determining a service life of said filter unit based on the measured amount of the adsorbed chemical substance.
A gas cleaning apparatus comprising:
- a filter for removing a chemical substance from a gas, said filter including a specific portion having a removal capacity for said substance that is lower than a removal capacity of a remainder of said filter for said substance;
- and
- a sensor arranged downstream of said specific portion to sense said substance.
An apparatus for exposing a photosensitive substrate with an image of a pattern on a mask, comprising:
- a filter for removing a chemical substance from a gas in a chamber, said filter including a specific portion having a removal capacity for said substance that is lower than a removal capacity of a remainder of said filter for said substance;
- and
- a sensor arranged downstream of said specific portion to sense the substance.
Dependencies are inferred from the claim text.