Exposure apparatus and device manufacturing method
An exposure apparatus exposes a substrate to light via a reticle in a vacuum. A projection optical system projects a pattern of the reticle onto the substrate, a stage holds the substrate and moves, and first and second partitions define an exhaust space between a first space accommodating at least a part of the projection optical system and a stage space accommodating the stage. The first partition includes a first opening to make the light pass between the first space and the exhaust space, and the second partition includes a second opening to make the light pass between the exhaust space and the stage space. A first supply system supplies fluid into the stage space, and a first exhaust system recovers fluid from the stage space through the second opening and the exhaust space. A pressure in the exhaust space is lower than those in the first space and the stage space.
1. An exposure apparatus for exposing a substrate to light via a reticle in a vacuum atmosphere, said apparatus comprising:
a projection optical system configured to project a pattern of the reticle onto the substrate;
a stage configured to hold the substrate and to move;
first and second partitions configured to define an exhaust space between a first space which accommodates at least a part of said projection optical system and a stage space which accommodates said stage, said first partition including a first opening configured to make the light pass between the first space and the exhaust space, and said second partition including a second opening configured to make the light pass between the exhaust space and the stage space;
a first supply system configured to supply fluid into the stage space; and
a first exhaust system configured to recover fluid from the stage space through said second opening and the exhaust space,
wherein said first exhaust system is configured to set a pressure in the exhaust space to be lower than those in the first space and the stage space.
2. An apparatus according to claim 1 , further comprising:
a reticle stage configured to hold the reticle and to move;
a third partition configured to partition a second space which accommodates at least a part of said projection optical system and a reticle stage space which accommodates said reticle stage, said third partition including a third opening configured to make the light pass between the second space and the reticle stage space; and
a second exhaust system configured to recover fluid from the reticle stage space through the third opening and the second space.
3. An apparatus according to claim 2 , wherein said second exhaust system is configured to set a partial pressure of gas outgassed in the second space to be lower than a partial pressure of gas outgassed in the reticle stage.
4. An apparatus according to claim 2 , further comprising a fourth partition configured to partition the first space and the second space, said fourth partition including a fourth opening configured to make the light pass between the first space and the second space.
5. An apparatus according to claim 4 , wherein said second exhaust system is configured to set a pressure in the second space to be lower than that in the first space.
6. An apparatus according to claim 1 , further comprising a first sensor configured to measure pressure in the stage space,
wherein said first supply system is configured to supply inert gas as the fluid so as to keep the pressure in the stage space constant based on measurement made by said first sensor.
7. An apparatus according to claim 6 , further comprising a second sensor arranged on said substrate stage,
wherein said first supply system is configured to supply inert gas from a region which surrounds said second sensor.
8. An apparatus according to claim 7 , further comprising a partition configured to surround said second sensor,
wherein said first supply system is configured to supply inert gas from a region between said partition and said second sensor.
9. An apparatus according to claim 1 , wherein said first supply system is configured to supply inert gas into a gap between said second partition and said substrate stage.
10. An apparatus according to claim 1 , wherein a pressure in the stage space is higher than 0.1 Pa and lower than 10 Pa.
11. An apparatus according to claim 1 , wherein a pressure in the first space is higher than 0.1 Pa and lower than 10 Pa.
12. An apparatus according to claim 1 , wherein said first supply system is configured to supply inert gas as the fluid.
13. An apparatus according to claim 8 , further comprising a second supply system configured to supply inert gas into the first space.
14. An apparatus according to claim 13 , further comprising a third sensor configured to measure pressure in the first space,
wherein said second supply system is configured to supply the inert gas so as to keep the pressure in the first space constant based on measurement made by said third sensor.
15. An apparatus according to claim 1 , further comprising:
a chamber configured to define each of the spaces; and
a first support configured to support said second partition substantially independently of said chamber.
16. An apparatus according to claim 1 , further comprising:
a chamber configured to define each of the spaces; and
a second support configured to support said first supply system substantially independently of said chamber.
17. An apparatus according to claim 1 , further comprising a cooling mechanism configured to cool said second partition.
18. An apparatus according to claim 1 , wherein a wavelength of the light is not shorter than 0.5 nm and not longer than 20 nm.
19. A method of manufacturing a device, said method comprising steps of:
exposing a substrate to light via a reticle using an exposure apparatus as defined in claim 1 ;
developing the exposed substrate; and
processing the developed substrate to manufacture the device.