Imaging apparatus

• US 6,778,257 B2
• Filed: 07/23/2002
• Issued: 08/17/2004
• Est. Priority Date: 07/24/2001
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Kruizinga, Borgert, Hintersteiner, Jason Douglas, Ryzhikov, Lev, Oskotsky, Mark, Sakin, Lev, McCarthy, Matthew Eugene, Bleeker, Arno Jan, Van Der Mast, Karel Diederick, De Jager, Pieter Willem Herman, Visser, Huibert, Smirnov, Stanislav, Snijders, Bart
• Primary Examiner(s): Kim, Peter B.
• Application Number:
  US10/200,577
• Publication Number:
  US 20030030781A1
• Time in Patent Office: 756 Days
• Field of Search: 355/67, 355/53, 355/41, 355/46, 355/77, 430/5, 430/30, 359/618, 359/224, 359/872, 250/492.22, 353/30, 347/239
• 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

Abstract

An imaging apparatus according to one embodiment of the invention includes a programmable patterning structure configured to pattern a projection beam of radiation according to a desired pattern. The programmable patterning structure includes a plurality of separate patterning sub-elements, each sub-element being configured to generate a patterned sub-beam. At least one of the separate patterning sub-elements is configured to generate a patterned sub-beam whose cross-section contains regions of different intensities. The imaging apparatus also includes a combining structure configured to combine the plurality of patterned sub-beams into a single patterned image, and a projection system configured to project the patterned image onto a target portion of a substrate.

Claims

1. An imaging apparatus comprising:

a radiation system configured to provide a beam of radiation;

a programmable patterning structure configured to pattern the beam according to a desired pattern, the programmable patterning structure including a plurality of separate patterning sub-elements, each sub-element being configured to generate a patterned sub-beam;

a combining structure configured to combine the plurality of patterned sub-beams into a single patterned image;

at least one optical system arranged in an optical path between a corresponding one of the plurality of separate patterning sub-elements and the combining structure;

a substrate table configured to hold a substrate; and

a projection system configured to project the patterned image onto a target portion of the substrate,

wherein at least one patterning sub-element is configured to generate a patterned sub-beam whose cross-section contains regions of different intensities, and

wherein said combining structure comprises at least one among a reflector and a beam splitter.

2. The imaging apparatus according to claim 1, wherein said combining structure comprises a plurality of separate optical channels, each optical channel corresponding to one of said separate patterning sub-elements and being configured to project an image of said patterning sub-element into an object plane of said projection system.

3. The imaging apparatus according to claim 2, wherein said plurality of separate optical channels are arranged to project reduced images of said separate patterning sub-elements.

4. The imaging apparatus according to claim 1, wherein said combining structure includes a beam splitter.

5. The imaging apparatus according to claim 1, wherein said programmable patterning structure comprises first to fourth separate patterning sub-elements, and

wherein said combining structure comprises first to third beam splitters, and

wherein said first beam splitter is configured to combine patterned sub-beams from said first and second separate patterning sub-elements to form a first combined beam, and

wherein said second beam splitter is configured to combine a patterned sub-beam from said third separate patterning sub-element with the first combined beam to form a second combined beam, and

wherein said third beam splitter is configured to combine a patterned sub-beam from said fourth separate patterning sub-element with the second combined beam to form a third combined beam, and

wherein said projection system is configured to projected the third combined beam onto the substrate.

6. The imaging apparatus according to claim 1, wherein said programmable patterning structure comprises first to fourth separate patterning sub-elements, and

wherein said combining structure comprises first to third beam splitters, and

wherein said first beam splitter is configured to combine patterned sub-beams from said first and second separate patterning sub-elements to form a first combined beam, and

wherein said second beam splitter is configured to combine patterned sub-beams from said third and fourth separate patterning sub-elements to form a second combined beam, and

wherein said third beam splitter is configured to combine the first combined beam with the second combined beam to form a third combined beam, and

wherein said projection system is configured to projected the third combined beam onto the substrate.

7. The imaging apparatus according to claim 1, wherein said separate patterning sub-elements are arranged around an imaginary circle parallel to the object plane, and

wherein said apparatus comprises a plurality of optical systems, each optical system corresponding to one of said separate patterning sub-elements and having an optical axis extending generally radially of said imaginary circle, and a corresponding plurality of folding mirrors, each folding mirror configured to direct a beam output by said corresponding optical system to intersect the object plane.

8. The imaging apparatus according to claim 7, further comprising an additional separate patterning sub-element and an additional optical system having an optical axis intersecting said object plane and configured to project an image of said additional separate patterning sub-element onto the object plane.

9. The imaging apparatus according to claim 7, wherein each optical system is configured to process a corresponding one of the plurality of patterned sub-beams.

10. The imaging apparatus according to claim 1, wherein said combining structure comprises a segmented lens forming the first element in said projection system.

11. The imaging apparatus according to claim 1, wherein each separate patterning sub-element comprises an array of individually controllable radiation modulating devices.

12. The imaging apparatus according to claim 11, wherein said plurality of separate patterning sub-elements are mounted in a staggered array on a carrier plate.

13. The imaging apparatus according to claim 1, wherein each of said separate patterning sub-elements comprises a carrier plate having mounted thereon a plurality of separate arrays of individually controllable radiation modulating devices, said separate arrays being mounted in a staggered array.

14. The imaging apparatus according to claim 11, wherein each of said individually controllable radiation modulating devices comprises at least one among a pixel of a liquid crystal device and a moveable mirror.

15. The imaging apparatus according to claim 1, wherein said substrate table is further configured to scan the substrate in a first direction during exposure of the target portion, and

wherein the single patterned image includes a staggered array having at least first and second rows of sub-images, each sub-image corresponding to one among the plurality of patterned sub-beams, and

wherein each of the first and second rows extends in a second direction perpendicular to the first direction, and

wherein the dimensions of the sub-images in the second direction are greater than the spaces between adjacent sub-images in the second direction, and

wherein the sub-images of the second row are aligned along the first direction with spaces between sub-images of the first row.

16. The imaging apparatus according to claim 15, wherein the staggered array has third and fourth rows of sub-images, and

wherein each of the third and fourth rows extends in a second direction perpendicular to the first direction, and

wherein the first and third rows are on opposite sides of the second row, and

wherein sub-images of the third row are offset from sub-images of the first row along said second direction by a first offset distance less than the length in the second direction of one of the sub-images, and

wherein the second and fourth rows are on opposite sides of the third row, and

wherein sub-images of the fourth row are offset from sub-images of the second row along said second direction by the first offset distance.

17. The imaging apparatus according to claim 15, wherein each of the sub-images includes a staggered array of images of separate arrays of individually controllable radiation modulating devices.

18. The imaging apparatus according to claim 1, wherein said combining structure comprises a three-way beam splitter and two folding mirrors.

19. The imaging apparatus according to claim 1, wherein said at least one optical system includes a contrast aperture.

20. The imaging apparatus according to claim 1, wherein said at least one optical system includes Scheimpflug optics.

21. The imaging apparatus according to claim 1, wherein said at least one optical system is configured to reduce an image of the corresponding patterning sub-element.

22. A device manufacturing method, said method comprising:

using a radiation system to provide a beam of radiation;

generating a plurality of patterned sub-beams based on the beam, at least one sub-beam having a cross-section that contains regions of different intensities;

combining the plurality of patterned sub-beams into a single patterned image;

passing at least one of the patterned sub-beams through an optical system prior to said combining, and

projecting the patterned image onto a target portion of a layer of radiation-sensitive material that at least partially covers a substrate,

wherein said combining includes at least one among (1) using a reflector to reflect the at least one patterned sub-beam and (2) passing the at least one patterned sub-beam through a beam splitter.

23. The device manufacturing method according to claim 22, said method further comprising scanning the substrate in a first direction during exposure of the target portion, and

wherein the single patterned image includes a staggered array having at least first and second rows of sub-images, each sub-image corresponding to one among the plurality of patterned sub-beams, and

wherein each of the first and second rows extends in a second direction perpendicular to the first direction, and

wherein the dimensions of the sub-images in the second direction are greater than the spaces between adjacent sub-images in the second direction, and

wherein the sub-images of the second row are aligned along the first direction with spaces between sub-images of the first row.

24. A device manufactured according to the method of claim 22.

25. The device manufacturing method according to claim 22, wherein said passing at least one of the patterned sub-beams through an optical system includes reducing an image of the corresponding patterning sub-element.

26. The device manufacturing method according to claim 22, wherein said passing at least one of the patterned sub-beams through an optical system includes passing the patterned sub-beam through a contrast aperture.

27. The device manufacturing method according to claim 22, wherein said combining includes passing at least three of the patterned sub-beams through a single beam-splitter.

28. The device manufacturing method according to claim 22, wherein said combining includes projecting the patterned image onto a segmented lens element.