Lithographic apparatus and device manufacturing method

• US 20050068510A1
• Filed: 09/22/2004
• Published: 03/31/2005
• Est. Priority Date: 09/22/2003
• Status: Active Grant

• Current Assignee: ASML Holding NV, ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Bleeker, Arno Jan, Troost, Kars Zeger, Kochersperger, Peter C., Adrianus Franken, Dominicus Jacobus Petrus
• Granted Patent: US 7,411,652 B2
• Time in Patent Office: Days
• US Class Current: 355/67
• CPC Class Codes: G03F 7/70283 Mask effects on the imaging process
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: G03F 7/703 Non-planar pattern areas or non-planar masks, e.g. curved masks or substrates
• CPC Class Codes: G03F 7/707 Chucks, e.g. chucking or un-chucking operations or structural details
• CPC Class Codes: G03F 7/70783 Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight

Abstract

One or more patterning arrays are mounted to a mounting plate via height adjustment structures that enable the flatness of the active surfaces of the patterning arrays to be controlled. The height adjustment structures may comprise an array of piezoelectric actuators or screws. Alternatively, the backside of the patterning means may be polished to optical flatness and bonded by crystal bonding to an optically flat surface of a rigid mounting body.

Claims

1. A lithographic apparatus, comprising:

an illumination system that supplies a beam of radiation;

a patterning array of individually controllable elements having an active surface that is used to pattern the beam;

a mounting plate on which said patterning array is mounted;

a height adjustment structure that locally adjusts a height of the active surface of said patterning array; and

a projection system that projects the patterned beam onto a target portion of a substrate.

2. The apparatus of claim 1, wherein said height adjustment structure comprises:

a level sensor to detect unflatness in the patterning array; and

a feedback loop to control the local adjustment applied to the patterning array.

3. The apparatus of claim 1, wherein said height adjustment structure comprises an array of piezoelectric elements.

4. The apparatus of claim 1, wherein said height adjustment structure comprises an array of fasteners passing through threaded holes in the mounting plate that bear against the patterning array.

5. The apparatus of claim 1, further comprising:

a plurality of the patterning arrays provided on a common mounting member, and

respective height adjustment structures, whereby the height adjustment structures allow the plurality of the patterning arrays to be mutually leveled.

6. A lithographic apparatus, comprising:

an illumination system that supplies a beam of radiation;

a patterning array of individually controllable elements that pattern the beam; and

a projection system that projects the patterned beam onto a target portion of a substrate,

wherein said patterning array comprises,

a plurality of active elements disposed on a first surface of a substrate,

a second surface of said substrate opposite said first substrate being optically flat, and

a rigid body having an optically flat surface to which said second surface of said substrate is coupled.

7. The apparatus of claim 6, wherein said rigid body is mounted to a mounting plate via a that adjusts a global tilt of the patterning arrays.

8. The apparatus of claim 7, wherein said rigid body is mounted to substantially prevent distortion of the patterning array in the event of thermal expansion or contraction of the mounting plate.

9. The apparatus of claim 6, wherein said second surface of said substrate is coupled to said flat surface of said rigid body using one of direct crystal bonding or ansprengen.

10. A device manufacturing method, comprising:

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

providing a beam of radiation using a radiation system;

using an active surface of a patterning array to pattern the beam;

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

mounting the patterning array to a mounting plate or rigid body in such a manner as to ensure the active surface is substantially flat.

11. A device manufacturing method using a maskless lithography system, the method comprising:

illuminating a patterning array assembly having a plurality of patterning arrays, wherein said patterning array assembly is in a first orientation in a first plane;

adjusting a position of at least one patterning array in said patterning array assembly from the first orientation in the first plane to a second orientation; and

exposing an object with the patterned light from the patterning array assembly.

12. The method of claim 11, wherein:

said first plane is coplanar with at least one other patterning array in the patterning array assembly, and

said second orientation is not coplanar with the at least one other patterning array.

13. The method of claim 12, wherein said second orientation is a second plane.

14. The method of claim 13, wherein said second orientation is parallel to said first plane.

15. The method of claim 13, wherein said second orientation is tilted at an angle with respect to said first plane.

16. The method of claim 12, wherein said second orientation is curved with respect to said first plane.

17. The method of claim 11, wherein the position of said at least one patterning array is adjusted to compensate for focal deviation of the patterned light at said object.

18. The method of claim 11, wherein the position of said at least one patterning array is adjusted actively.

19. The method of claim 11, wherein the position of said at least one patterning array is adjusted using pistons.

20. The method of claim 11, wherein the position of said at least one patterning array is adjusted manually.

21. The method of claim 11, wherein the position of said at least one patterning array is adjusted using fasteners.

22. The method of claim 11, wherein said method is performed during an initial setup of the maskless lithography system.

23. The method of claim 11, wherein said method is performed periodically for maintenance of the maskless lithography system.

24. A device manufacturing method using a maskless lithography system, comprising:

illuminating a patterning array assembly having a plurality of patterning arrays, wherein each patterning array in the patterning array assembly has a first position;

adjusting at least one patterning array from said first position to a second position;

transmitting light from the patterning array assembly through an optical system; and

exposing an object with the transmitted light,

wherein said first position is coplanar with the plurality of patterning arrays in the patterning array assembly and said second position is not coplanar with the patterning array assembly.

25. The method of claim 24, wherein said second position is parallel to said first position.

26. The method of claim 24, wherein said adjusting step comprises tilting the at least one patterning array.

27. The method of claim 24, wherein said adjusting step comprises bending the at least one patterning array.

28. A device manufacturing method using a maskless lithography system having a plurality of patterning arrays in a patterning array assembly, said patterning array assembly having a reflective surface, said method comprising:

adjusting a position of at least one of said plurality of patterning arrays based on a detected aberration;

illuminating said patterning array assembly;

transmitting light reflected by said patterning array assembly through an optical system; and

exposing an object with said light,

wherein said adjusting step causes the reflective surface of said patterning array assembly to deviate from a flat plane.

29. The method of claim 28, wherein said adjusting step comprises:

receiving exposure data at a plane of said object;

determining corrective adjustment needed for said at least one of said plurality of patterning arrays, wherein said adjustment is based on said exposure data; and

adjusting said at least one of said plurality of patterning arrays to reduce said aberration.

30. A maskless lithography system, comprising:

an illumination source that produces light;

a patterning array assembly having a plurality of patterning arrays, each patterning array in the plurality of patterning arrays being coupled to a respective adjuster;

an optics system that conditions the light; and

an image plane in which the light is received,

wherein each of the respective adjusters moves a respective one of the patterning arrays to correct for an optical aberration in the light received by the object, such that a surface of the patterning array assembly deviates from a flat plane.

31. The system of claim 30, wherein said aberration is total focus deviation.

32. The system of claim 30, wherein said adjuster is a set of adjusters.

33. The system of claim 32, wherein said set of adjusters tilts its respective patterning array.

34. The system of claim 32, wherein said set of adjusters bends its respective patterning array.

35. The system of claim 32, wherein said set of adjusters changes an elevation of its respective patterning array.

36. The system of claim 32, further comprising:

a controller that controls said adjusters.

37. The system of claim 36, wherein said adjusters are pistons.

38. The system of claim 32, wherein said adjusters are screws.