Optical apparatus with adjustable action of force on an optical module

• US 9,766,549 B2
• Filed: 02/12/2015
• Issued: 09/19/2017
• Est. Priority Date: 06/10/2008
• Status: Expired due to Fees

• Current Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung)
• Original Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung)
• Inventors: Kwan, Yim-Bun Patrick
• Primary Examiner(s): Whitesell Gordon, Steven H
• Application Number:
  US14/620,589
• Publication Number:
  US 20150227055A1
• Time in Patent Office: 950 Days
• Field of Search: None
• CPC Class Codes: G02B 7/003 Alignment of optical elements G02B7/001, G02B7/002 take precedence; for mirrors G02B7/1822
• CPC Class Codes: G02B 7/028 with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation
• CPC Class Codes: G03F 7/70141 Illumination system adjustment, e.g. adjustments during exposure or alignment during assembly of illumination system
• CPC Class Codes: G03F 7/70816 Bearings
• CPC Class Codes: G03F 7/70833 Mounting of optical systems, e.g. mounting of illumination system, projection system or stage systems on base-plate or ground
• CPC Class Codes: G03F 7/70975 Assembly, maintenance, transport or storage of apparatus

Abstract

The disclosure pertains to an optical apparatus, in particular for microlithography, that includes an optical module, a support structure and a connection apparatus. The connection apparatus includes at least one connection unit which includes a first connector part and a second connector part. The first connector part is connected to the optical module, and the second connector part is connected to the support structure.

Claims

1. An optical apparatus, comprising:

an optical module;

a support structure; and

a connection apparatus, comprising;

a connection unit, comprising;

a first connector part connected to the optical module;

a second connector part connected to the support structure; and

at least a portion of a positioning device configured to act on the first and second connector parts,

wherein;

the connection unit has an adjustment state and an installed state;

the first connector part has a first contact surface with a first main curvature defining a first main curvature axis;

the second connector part has a second contact surface with a second main curvature defining a second main curvature axis;

the second main curvature is matched to the first main curvature;

in the installed state of the connection unit, the first contact surface contacts the second contact surface;

in the adjustment state of the connection unit, a first gap between the first and second contact surfaces is maintained in a non-contact manner via a fluidic force so that a compensating motion between the first and second contact surfaces about the first main curvature axis is possible without the occurrence of any action of force between the first and second connector parts resulting from the compensating motion;

the first gap is narrow;

the first connector part comprises a first connector element and a second connector element;

the first connector element has a third contact surface with a third main curvature defining a third main curvature axis;

the second connector element has a fourth contact surface with a fourth main curvature defining a fourth main curvature axis;

in the installed state of the connection unit, the fourth main curvature is matched to the third main curvature and the third contact surface contacts the fourth contact surface;

the connection apparatus comprises at least part of the positioning device configured to act on the first and second connector elements;

in the adjustment state of the connection unit, a second gap between the third and fourth contact surfaces is maintained in a non-contact manner so that a compensating motion between the third and fourth contact surfaces about the third main curvature axis is possible without the occurrence of any action of force between the third and fourth connector parts resulting from the compensating motion;

the second gap is narrow;

the positioning device comprises a force generation device, a detection device and a control device connected with the force generation device and the detection device;

the detection device is configured the detect a value of a variable representative of a dimension of the second gap and to pass on a corresponding second gap measurement signal to the control device;

the control device is configured to generate from the second gap measurement signal and a second gap setpoint value a second gap control signal and to pass the second gap control signal on to the force generation device; and

the force generation device is configured to generate an action of force between the first and second connector elements as a function of the second gap control signal to maintain the second gap; and

the optical apparatus is configured to be used in microlithography.

2. The optical apparatus according to claim 1, wherein:

in the adjustment state of the connection unit, the force generation device maintains the first gap by applying a force of attraction between the optical module and the support structure.

3. The optical apparatus according to claim 2, wherein, in the adjustment state of the connection unit, the force generation device maintains the first gap by applying the force of attraction between the first and second connector parts.

4. The optical apparatus according to claim 1, wherein:

in the adjustment state of the connection unit, the force generation device maintains the first gap by applying a force of repulsion between the optical module and the support structure.

5. The optical apparatus according to claim 4, wherein, in the adjustment state of the connection unit, the force generation device maintains the first gap by applying the force of repulsion between the first and second connector parts.

6. The optical apparatus according to claim 1, wherein:

in the adjustment state of the connection unit, the force generation device maintains the first gap by applying the action of force between the optical module and the support structure.

7. The optical apparatus according to claim 6, in the adjustment state of the connection unit, the force generation device maintains the first gap by applying the action of force between the first and second connector parts.

8. The optical apparatus according to claim 6, wherein:

the action of force comprises an electromagnetic force;

a member has an electrically conducting section that can be impinged upon by electrical current; and

the member is selected from the group consisting of the optical module, the support structure and combinations thereof.

9. The optical apparatus according to claim 6, wherein:

the action of force comprises an electrostatic force;

a member has an electrically conducting section that can be impinged upon by electrical charge; and

the member is selected from the group consisting of the optical module, the support structure and combinations thereof.

10. The optical apparatus according to claim 6, wherein:

the action of force comprises the fluidic force;

at least one of the first and second connector parts comprises a feed device configured to provide a fluid in the first gap.

11. The optical apparatus according to claim 1, wherein:

the detection device is configured to detect a value of a variable representative of a dimension of the first gap and to pass on a corresponding first gap measurement signal to the control device;

the control device is configured to generate from the first gap measurement signal and a first gap setpoint value a first gap control signal and to pass the first gap control signal on to the force generation device; and

the force generation device is configured to generate an action of force between the first and second connector parts as a function of the first gap control signal to maintain the first gap.

12. The optical apparatus according to claim 1, wherein:

in the adjustment state of the connection unit, the force generation device maintains the second gap between by applying an action of force between the optical module and the support structure.

13. The optical apparatus according to claim 1, wherein:

the connection apparatus comprises a further connection unit, the further connection unit comprising a third connector part connected with the optical module and a fourth connector part connected with the support structure;

the third connector part has a third contact surface with a third main curvature defining a third main curvature axis;

the fourth connector part has a fourth contact surface with a fourth main curvature defining a fourth main curvature axis;

the fourth main curvature is matched to the third main curvature;

in the installed state of the connection unit, the third contact surface contacts the fourth contact surface in the installed state;

the connection apparatus comprises at least part of the positioning device configured to act on the third and fourth connector parts; and

in the adjustment state of the connection unit, the second gap is maintained in a non-contact manner so that a compensating motion between the third and fourth contact surfaces about the third main curvature axis is possible without the occurrence of any action of force between the third and fourth connector parts resulting from the compensating motion.

14. The optical apparatus according to claim 13, wherein the positioning device is configured to substantially synchronously reduce the first and second gaps.

15. The optical apparatus according to claim 1, wherein the optical apparatus is configured so that, when the optical module is used to transfer a projection pattern onto a substrate, the connection unit is in the installed state.

16. A method, comprising:

using a connection apparatus to connect a support structure with an optical module configured for use in microlithography, wherein;

the connection apparatus comprises a connection unit comprising a first connector part and a second connector part;

the first connector part is connected to the optical module and the second connector part is connected to the support structure;

the first connector part has a first contact surface with a first main curvature defining a first main curvature axis;

the second connector part has a second contact surface with a second main curvature defining a second main curvature axis;

the first main curvature axis matches to the second main curvature;

the first connector part comprises a first connector element and a second connector element;

the first connector element has a third contact surface with a third main curvature defining a third main curvature axis;

the second connector element has a fourth contact with a fourth main curvature defining a fourth main curvature axis;

the fourth main curvature is matched to the third main curvature;

the method comprises;

a) bringing the optical module and the support structure closer to each other so that the first contact surface contacts the second contact surface and so that the third contact surface contacts the fourth contact surface in an installed state; and

b) in an adjustment state before a), maintaining a first gap between the first and second contact surfaces in a non-contact manner via a fluidic force so that a compensating motion between the first and second contact surfaces about the first main curvature axis is possible without the occurrence of any action of force between the first and second connector parts resulting from the compensating motion, and maintaining a second gap between the third and fourth contact surfaces in a non-contact manner so that a second compensating motion between the third and fourth contact surfaces about the third main curvature axis is possible without the occurrence of any action of force between the first and second connector elements resulting from the second compensating motion,

the method further comprises;

detecting a value of a variable representative of a dimension of the second gap;

passing a corresponding second gap measurement signal to a control device;

generating a second gap control signal from the second gap measurement signal and a second gap setpoint value;

passing the second gap control signal to the force generation device; and

using the force generation device to maintain the second gap generates an action of force between the first and second connector elements as a function of the second control signal;

the first gap is narrow; and

the second gap is narrow.

17. The method according to claim 16, comprising applying a force of action comprising the fluidic force between the optical component and the support structure to maintain the first gap.

18. The method according to claim 17, wherein the force of action further comprises at least one force selected from the group consisting of an electrical force and a magnetic force.

19. The method according to claim 16, comprising:

detecting a value of a variable representative of a dimension of the first gap;

passing a corresponding first gap measurement signal to the control device;

generating a first gap control signal from the first gap measurement signal and a first gap setpoint value;

passing the first gap control signal to the force generation device; and

using the force generation device to generate the action of force between the first and second connector parts as a function of the first gap control signal to maintain the first gap.

20. The method according to claim 16, comprising applying the action of force between the optical module and the support structure to maintain the second gap.

21. The method according to claim 16, wherein:

the connection apparatus comprises a third connector part connected to the optical module and a fourth connector part connected to the support structure;

the third connector part has a fifth contact surface with a fifth main curvature, which defines a fifth main curvature axis;

the fourth connector part has a sixth contact surface with a sixth main curvature matched to the fifth main curvature, which defines a sixth main curvature axis;

the optical module and the support structure are brought closer to one another so that the fifth contact surface contacts the sixth contact surface in the installed state; and

in the adjustment state a third narrow gap between the fifth contact surface and the sixth contact surface is maintained in a non-contact manner so that a third compensating motion between the fifth contact surface and the sixth contact surface about the fifth main curvature axis is possible without the occurrence of any action of force between the third connector part and the fourth connector part resulting from the third compensating motion.

22. The method according to claim 21, wherein the first and second gaps are substantially synchronously reduced.

23. The method according to claim 21, comprising reducing the first and second gaps so that the first and second contact surfaces contact each other substantially simultaneously, and so that the fifth and sixth contact surfaces contact each other substantially simultaneously.

24. The method according to claim 16, wherein the optical module defines a circumferential direction and a radial direction, and the first main curvature axis runs in a direction that has at least one component in the circumferential direction and/or the radial direction.

25. The method according to claim 16, wherein at least one of the connector parts comprises a flexible decoupling section in the direction of the first main curvature axis, and the decoupling section is designed for decoupling the forces in the direction of the first main curvature axis between the optical module and the support structure.

26. The method according to claim 16, wherein the adjustment state compensating motions in at least two degrees of freedom without a force of action between the components of the connection unit resulting from the compensating motions.

27. The method according to claim 16, further comprising, while the connection unit is in the installed state, using the optical module to transfer a projection pattern onto a substrate.