 Paraffin bath |
| What is claimed is: 1. A paraffin bath apparatus for melting paraffin comprising: a tub being ... |
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| Desiccant assisted air conditioner |
| I claim: 1. A desiccant assisted air conditioning system for delivering dehumidified refrigerated ... |
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| Hybrid heat pump and desiccant space conditioning system and control method |
| OF THE INVENTION Referring now to FIG. 1 there is shown in schematic form a multi wheel desiccant/... |
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| Absorption heat pump and desiccant assisted air conditioning apparatus |
| According to the first embodiment of the invention, a desiccant assisted air conditioning apparatus ... |
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| Absorption heat pump and desiccant assisted air conditioner |
| It is an object of the present invention to provide an absorption heat pump device for use in an ... |
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| Desiccant assisted air conditioning system |
| It is therefore necessary to develop a high efficiency air conditioning unit combining desiccant ... |
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| Desiccant assisted air conditioning apparatus |
| It is therefore an object of the present invention to achieve a desiccant assisted air conditioning ... |
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| System and method for controlling communication-executable refrigerator |
| Therefore, the present invention has been made in view of the above problems, and it is an object ... |
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| Film cartridges, films and cameras adapted for use therewith |
| It is a general object of the present invention to provide film cartridges, films and cameras ... |
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Wafer holding device in an exposure apparatus
| Details |
Inventors: Hara, Shinichi; Sakamoto, Eiji; Ebinuma, Ryuichi;
Assignee: Canon Kabushiki Kaisha (Tokyo, JP)
Primary Examiner: Dzierzynski; Paul M.
Assistant Examiner: Nguyen; Kiet T.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper & Scinto
A substrate holding device includes a chuck having an attracting surface for holding a substrate, an inside space and an inside heat pipe structure provided in the inside space, the heat pipe structure removing generated heat by evaporation of a liquid medium; a temperature controlling block having a structure that allows flow of a temperature controlling medium therethrough, the temperature controlling block being thermally coupled to the attracting surface of the chuck through the heat pipe structure; and a stage for moving the chuck and the temperature controlling block as a unit, and for supporting the chuck through the temperature controlling block. |
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DETAILED DESCRIPTION It is accordingly an object of the present invention to provide an exposure wafer holding device, by which the wafer can be cooled without degradation of the pattern transfer precision.
In an exposure wafer holding device according to one aspect of the present invention, which is for use in an exposure apparatus having a wafer chuck mounted to a stage of low rigidity, the wafer chuck is provided with a hollow member having a heat pipe structure and, between the wafer chuck and the stage, a cooling plate having an internal structure allowing circulation of a cooling medium is interposed.
The hollow member may be divided along a longitudinal direction.
With the provision of a wafer chuck by using a hollow member having a heat pipe structure, the heat flow impinging on the heat receiving surface of the wafer during the exposure can be diffused within the hollow member of the wafer chuck.
Therefore, the heat flow density at the cooling surface of the wafer chuck (the surface contacting the cooling plate having an internal structure for allowing circulation of the cooling medium), can be decreased in accordance with the ratio in area between the heat receiving surface and the cooling surface.
This enables considerable reduction in the flow rate of the cooling medium, flowing through the cooling plate.
As a result, even if the wafer chuck to which a wafer is to be attracted is mounted to a stage having low rigidity, it is possible to maintain displacement of the wafer sufficiently small during the exposure process and, advantageously, it is possible to cool the wafer without degradation of the pattern transfer precision.
Since, in an X-ray exposure apparatus using synchrotron radiation light as a light source, a wafer chuck is placed upstanding, the dividing of the hollow member longitudinally allows efficient circulation of the operative fluid.
It is therefore possible to efficiently prevent a dry-out phenomenon.
It is another object of the present invention to provide a wafer holding device with simplified control and structure, by which displacement of an attracting block is prevented even with a small flow rate of a level not causing a non-negligible effect of vibration
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Lighting 
