Patent Number: 
Section: claims

1. A weight compensation apparatus for compensating for a weight of a stage that is movable along a vertical reference plane, said apparatus comprising: a pulley having a pulley shaft;  a belt which is wound around and supported by said pulley and has the stage at one end and a counter mass corresponding to the stage at the other end;  a hydrostatic bearing which has an arcuated bearing portion and supports the pulley shaft by causing a fluid to flow into a bearing gap between the bearing portion and the pulley shaft; and  a thrust bearing mechanism for resisting axial motion of said pulley by causing the fluid to flow into a gap between a thrust bearing portion and a side surface of said pulley. 2. The apparatus according to  claim 1 , wherein claim 1 the bearing portion of said hydrostatic bearing includes a portion made of a porous material, and  the fluid is supplied to the bearing gap via the porous material. 3. The apparatus according to  claim 1 , wherein said hydrostatic bearing is made of a magnetic material. claim 1 4. The apparatus according to  claim 1 , wherein said hydrostatic bearing comprises an electromagnet. claim 1 5. The apparatus according to  claim 1 , further comprising plural sets of said pulley, said belt and said hydrostatic bearing, wherein the stage is movable two-dimensionally along the vertical reference plane. claim 1 6. A stage apparatus comprising: a stage which moves in at least a vertical direction along a vertical reference plane;  a pulley disposed above said stage, said pulley having a pulley shaft;  a belt which is wound around and supported by said pulley and has said stage at one end and a counter mass corresponding to said stage at the other end;  a hydrostatic bearing which has an arcuated bearing portion and supports the pulley shaft by causing a fluid to flow into a bearing gap between the bearing portion and the pulley shaft; and  a thrust bearing mechanism for resisting axial motion of said pulley by causing the fluid to flow into a gap between a thrust bearing portion and a side surface of said pulley. 7. The apparatus according to  claim 6 , further comprising a damper for adjusting at least one of a tension and an effective length of said belt in order to provide damping in accordance with displacement of said stage. claim 6 8. The apparatus according to  claim 6 , wherein claim 6 the bearing portion of said hydrostatic bearing includes a portion made of a porous material, and  the fluid is supplied to the bearing gap via the porous material. 9. The apparatus according to  claim 6 , wherein said hydrostatic bearing is made of a magnetic material. claim 6 10. The apparatus according to  claim 6 , wherein said hydrostatic bearing comprises an electromagnet. claim 6 11. An exposure apparatus comprising: the stage apparatus defined in  claim 6 ;  claim 6 an exposure light source for generating exposure light;  a first holder for holding a mask;  a second holder for holding an object to be exposed on a stage; and  an exposure controller for irradiating the object held by said second holder with the exposure light having passed through the mask held by said first holder, while moving the stage apparatus. 12. The apparatus according to  claim 11 , claim 11 the exposure apparatus further comprising a display, a network interface, and a computer for executing network software,  wherein maintenance information of the exposure apparatus is communicated via said computer network. 13. The apparatus according to  claim 12 , wherein the network software is connected to an external network of a factory in which the exposure apparatus is installed, provides on said display a user interface for accessing a maintenance database provided by a vendor or user of the exposure apparatus, and enables obtaining information from the database via the external network. claim 12 14. A device manufacturing method comprising the steps of: installing a plurality of semiconductor manufacturing apparatuses including an exposure apparatus in a factory; and  manufacturing a semiconductor device by using the plurality of semiconductor manufacturing apparatuses,  wherein the exposure apparatus includes the stage apparatus defined in  claim 7 , an exposure light source for generating exposure light, a first holder for holding a mask, a second holder for holding an object to be exposed on a stage, and an exposure controller for irradiating the object held by the second holder with the exposure light having passed through the mask held by the first holder, while moving the stage apparatus.  claim 7 15. The method according to  claim 14 , further comprising the steps of: claim 14 connecting the plurality of semiconductor manufacturing apparatuses by a local area network;  connecting the local area network to an external network outside the factory;  acquiring the information about an X-ray exposure apparatus from a database on the external network by using the local area network and the external network; and  controlling the X-ray exposure apparatus on the basis of the acquired information. 16. The method according to  claim 15 , wherein a database provided by a vendor or user of the exposure apparatus is accessed via the external network to obtain maintenance information of the manufacturing apparatus by data communication, or production management is performed by data communication between the semiconductor manufacturing factory and another semiconductor manufacturing factory via the external network. claim 15 17. A semiconductor manufacturing factory comprising: a plurality of semiconductor manufacturing apparatuses including an exposure apparatus;  a local area network for connecting said plurality of semiconductor manufacturing apparatuses; and  a gateway which allows the local area network to access an external network outside the factory,  wherein the exposure apparatus includes the stage apparatus defined in  claim 7 , an exposure light source for generating exposure light, a first holder for holding a mask, a second holder for holding an object to be exposed on a stage, and an exposure controller for irradiating the object held by the second holder with the exposure light having passed through the mask held by the first holder, while moving the stage apparatus.  claim 7 18. An exposure apparatus maintenance method comprising the steps of: preparing a database for accumulating information about maintenance of the exposure apparatus, on an external network outside a factory in which an exposure apparatus is installed;  connecting the exposure apparatus to a local area network in the factory; and  maintaining the exposure apparatus on the basis of the information accumulated in the database by using the external network and the local area network,  wherein the exposure apparatus includes the stage apparatus defined in  claim 6 , an exposure light source for generating exposure light, a first holder for holding a mask, a second holder for holding an object to be exposed on a stage, and an exposure controller for irradiating the object held by the second holder with the exposure light having passed through the mask held by the first holder, while moving the stage apparatus.  claim 6 19. The apparatus according to  claim 6 , further comprising plural sets of said pulley, said belt and said hydrostatic bearing, wherein the stage is movable two-dimensionally along the vertical reference plane. claim 6