Lithographic apparatus, device manufacturing method, and device manufactured thereby

• US 6,597,429 B2
• Filed: 04/12/2001
• Issued: 07/22/2003
• Est. Priority Date: 04/17/2000
• Status: Expired due to Term

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Vijfvinkel, Jakob, Tabor, Rob, Schneider, Ronald M., Renkens, Marcel J. M., Bisschops, Theo H. J., Janssen, Eric W. A.
• Primary Examiner(s): Mathews, Alan A.
• Application Number:
  US09/833,077
• Publication Number:
  US 20020021425A1
• Time in Patent Office: 831 Days
• Field of Search: 355/53, 355/72, 355/75, 248/550, 248/562, 250/492.2
• US Class Current: 355/53
• CPC Class Codes: F16C 2300/62 low pressure, e.g. elements operating under vacuum conditions
• CPC Class Codes: F16C 29/025 Hydrostatic or aerostatic this type of bearing for rotary parts F16C32/06
• CPC Class Codes: F16C 32/0603 supported by a gas cushion, e.g. an air cushion
• CPC Class Codes: F16C 33/748 flowing to or from the sealing gap, e.g. vacuum seals with differential exhaust
• CPC Class Codes: F16F 15/0275 Control of stiffness
• CPC Class Codes: G03F 7/70816 Bearings
• CPC Class Codes: G03F 7/70841 Constructional issues related to vacuum environment, e.g. load-lock chamber
• CPC Class Codes: G03F 7/709 Vibration, e.g. vibration detection, compensation, suppression or isolation

Abstract

A lithographic projection apparatus comprises a vacuum chamber having a wall enclosing at least one of first and second object tables, the or each object table within the vacuum chamber being connected to positioning means for positioning the object table with respect to a projection system of the apparatus. The positioning means is provided with a pneumatic gravity compensator comprising a piston associated with the object table; a gas-filled pressure chamber, the gas in the pressure chamber acting on the movable member to at least partially counteract the weight of the object table; a gas bearing; and evacuating means for evacuating gas escaping through a gap between the movable member and a bearing surface of a cylindrical housing towards the vacuum chamber. A partially flexible rod connects the piston to the object table.

Claims

1. A lithographic projection apparatus comprising:

a radiation system which provides a projection beam of radiation;

a patterning structure support to support projection beam patterning structure which patterns the projection beam according to a desired pattern;

a substrate table to hold a substrate;

a projection system which projects the patterned beam onto a target portion of the substrate; and

a support member constructed and arranged to support a portion of the lithographic projection apparatus along a support direction and having a finite stiffness in a direction that is substantially perpendicular to the support direction,

wherein the stiffness of the support member is such that a deformation force in the perpendicular direction by the support member due to a deformation of the support member in the perpendicular direction substantially counteracts an opposite displacing force in the perpendicular direction due to a force substantially parallel to the support direction acting on the support member.

2. An apparatus according to claim 1, wherein the support member comprises a rod.

3. An apparatus according to claim 2, wherein the rod comprises a rigid part and a flexible part.

4. An apparatus according to claim 1, wherein the support member is provided with a hollow part.

5. An apparatus according to claim 4, wherein a conduit is arranged through the hollow part.

6. An apparatus according to claim 1, wherein the support member supports one of the patterning structure support and the substrate table.

7. An apparatus according to claim 1, wherein the patterning structure support comprises a mask table for holding a mask.

8. An apparatus according to claim 1, wherein the apparatus further comprises an isolated reference frame, and the support member is arranged to support the isolated reference frame.

9. An apparatus according to claim 1, wherein the radiation system comprises a radiation source.

10. An apparatus according to claim 1, wherein an auxiliary support structure to apply an additional force on the support member along the support direction is provided.

11. An apparatus according to claim 1, further comprising a vacuum chamber having a wall enclosing the support member, wherein the support member comprises:

a gas-filled pressure chamber, the gas in the pressure chamber acting on a movable member such as to at least partially counteract a force substantially parallel to the support direction, and

a pressure relief structure constructed and arranged to allow evacuation of gas escaping towards the vacuum chamber through a gap between the movable member and a bearing surface.

12. An apparatus according to claim 11, wherein the support member comprises a rod connected to the movable member.

13. An apparatus according to claim 11, wherein the support member further comprises a bearing supporting the movable member and maintaining the gap between the movable member and the bearing surface, the bearing comprising a gas bearing constructed and arranged to provide pressurized gas into the gap thereby generating forces tending to hold the movable member away from the bearing surface, and the pressure relief structure provided between the gas bearing and the vacuum chamber along the movable member so as to remove gas from the gap.

14. An apparatus according to claim 11, wherein the pressure relief structure comprises a conduit providing a fluid communication between the gap and at least one reservoir at a pressure higher than that of the vacuum chamber and lower than that of the gas to be removed from the gap.

15. An apparatus according to claim 11, wherein the pressure relief structure includes a fluid communication between the gap and at least one vacuum pump.

16. An apparatus according to claim 15, wherein the fluid communication comprises more than one elongated vacuum groove in the surface defining the gap, the vacuum grooves being generally parallel and each of the respective grooves being in communication with a progressively lower pressure vacuum in the direction of the vacuum chamber.

17. A lithographic projection apparatus comprising:

a radiation system which provides a projection beam of radiation;

a patterning structure support to support projection beam patterning structure which patterns the projection beam according to a desired pattern;

a substrate table to hold a substrate;

a projection system which projects the patterned beam onto a target portion of the substrate; and

a support member constructed and arranged to support a portion of the lithographic projection apparatus along a support direction and having a finite stiffness in a direction that is substantially perpendicular to the support direction;

wherein an auxiliary support structure to apply an additional force on the support member along the support direction is provided.

18. An apparatus according to claim 17, wherein the stiffness of the support member is such that a deformation force in the perpendicular direction by the support member due to a deformation of the support member in the perpendicular direction substantially counteracts an opposite displacing force in the perpendicular direction due to a force substantially parallel to the support direction acting on the support member.

19. An apparatus according to claim 17, wherein the support member is provided with a hollow part, and

wherein a conduit is arranged through the hollow part.

20. An apparatus according to claim 17, further comprising a vacuum chamber having a wall enclosing the support member, wherein the support member comprises:

a gas-filled pressure chamber, the gas in the pressure chamber acting on a movable member such as to at least partially counteract a force substantially parallel to the support direction, and

a pressure relief structure constructed and arranged to allow evacuation of gas escaping towards the vacuum chamber through a gap between the movable member and a bearing surface.

21. An apparatus according to claim 20, wherein the support member further comprises a bearing supporting the movable member and maintaining the gap between the movable member and the bearing surface, the bearing comprising a gas bearing constructed and arranged to provide pressurized gas into the gap thereby generating forces tending to hold the movable member away from the bearing surface, and the pressure relief structure provided between the gas bearing and the vacuum chamber along the movable member so as to remove gas from the gap.

22. An apparatus according to claim 17, wherein the apparatus further comprises an isolated reference frame, and the support member is arranged to support the isolated reference frame.

23. A lithographic projection apparatus comprising:

a radiation system which provides a projection beam of radiation;

a patterning structure support to support projection beam patterning structure which patterns the projection beam according to a desired pattern;

a substrate table to hold a substrate;

a projection system which projects the patterned beam onto a target portion of the substrate;

a support member constructed and arranged to support a portion of the lithographic projection apparatus along a support direction and having a finite stiffness in a direction that is substantially perpendicular to the support direction; and

a vacuum chamber having a wall enclosing the support member, wherein the support member comprises;

a rod,

a gas-filled pressure chamber, the gas in the pressure chamber acting on a movable member such as to at least partially counteract a force substantially parallel to the support direction, and

a pressure relief structure constructed and arranged to allow evacuation of gas escaping towards the vacuum chamber through a gap between the movable member and a bearing surface.

24. An apparatus according to claim 23, wherein the support member comprises a rod connected to the movable member.

25. An apparatus according to claim 23, wherein the support member further comprises a bearing supporting the movable member and maintaining the gap between the movable member and the bearing surface, the bearing comprising a gas bearing constructed and arranged to provide pressurized gas into the gap thereby generating forces tending to hold the movable member away from the bearing surface, and the pressure relief structure provided between the gas bearing and the vacuum chamber along the movable member so as to remove gas from the gap.

26. An apparatus according to claim 25, wherein the gas bearing comprises an elongate groove in one surface defining the gap;

and a gas supply which supplies gas under pressure to said elongate groove.

27. An apparatus according to claim 23, wherein the pressure relief structure comprises a conduit providing a fluid communication between the gap and at least one reservoir at a pressure higher than that of the vacuum chamber and lower than that of the gas to be removed from the gap.

28. An apparatus according to claim 27, wherein the conduit comprises at least one elongate groove in a surface defining the gap.

29. An apparatus according to claim 23, wherein the pressure relief structure includes a fluid communication between the gap and at least one vacuum pump.

30. An apparatus according to claim 29, wherein the fluid communication between the gap and the at least one vacuum pump comprises at least one elongate vacuum groove in a surface defining the gap.

31. An apparatus according to claim 30, wherein the fluid communication comprises more than one elongated vacuum groove in the surface defining the gap, the vacuum grooves being generally parallel and each of the respective grooves being in communication with a progressively lower pressure vacuum in the direction of the vacuum chamber.

32. An apparatus according to claim 23, wherein the movable member comprises a piston being journaled in a housing provided with the gas-filled pressure chamber, an inner wall of the housing providing the bearing surface.

33. A device manufacturing method, using a lithographic projection apparatus, comprising:

providing a substrate that is at least partially covered by a layer of radiation-sensitive material;

providing a projection beam of radiation;

patterning the projection beam of radiation with a pattern in its cross-section;

projecting the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material, and

supporting along a support direction one of a support structure of the lithographic projection apparatus, a substrate table of the lithographic projection apparatus and an isolated reference frame of the lithographic projection apparatus with a support member having a finite stiffness in a direction that is substantially perpendicular to the support direction of the support member, said stiffness of the support member is such that a deformation force in the perpendicular direction by the support member due to a deformation of the support member in the perpendicular direction substantially counteracts an opposite displacing force in the perpendicular direction due to a force substantially parallel to the support direction acting on the support member.

34. A device manufactured according to the method of claim 33.

35. A lithographic projection apparatus comprising:

a radiation system which provides a projection beam of radiation;

a patterning structure support to support projection beam patterning structure which patterns a projection beam according to a desired pattern;

a substrate table to hold a substrate;

a projection system which projects the patterned beam onto a target portion of the substrate; and

a support member, supporting a portion of the lithographic projection apparatus along a support direction and having a finite negative stiffness in a direction that is substantially perpendicular to the support direction.

36. An apparatus according to claim 35, wherein an auxiliary support structure to apply an additional force on the support member along the support direction is provided.

37. An apparatus according to claim 35, further comprising a vacuum chamber having a wall enclosing the support member, wherein the support member comprises:

a gas-filled pressure chamber, the gas in the pressure chamber acting on a movable member such as to at least partially counteract a force substantially parallel to the support direction, and

a pressure relief structure constructed and arranged to allow evacuation of gas escaping towards the vacuum chamber through a gap between the movable member and a bearing surface.

38. An apparatus according to claim 37, wherein the support member bearing surface, comprises a bearing supporting the movable member and maintaining the gap between member and the bearing surface, the bearing comprising a gas bearing and arranged to provide pressurized gas into the gap thereby generating forces hold the movable member away from the bearing surface, and the pressure relief provided between the gas bearing and the vacuum chamber along the movable to remove gas from the gap.

39. An apparatus according to claim 35, wherein the apparatus further comprises an isolated reference frame, and the support member is arranged to support the isolated reference frame.

40. An apparatus according to claim 35, wherein the support member is provided with a hollow part, and

wherein a conduit is arranged through the hollow part.