Lithographic apparatus and device manufacturing method using a compensation scheme for a patterning array

• US 7,466,394 B2
• Filed: 12/21/2005
• Issued: 12/16/2008
• Est. Priority Date: 12/21/2005
• Status: Expired due to Fees

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Baselmans, Johannes Jacobus Matheus, Troost, Kars Zeger
• Primary Examiner(s): Rutledge; Della J.
• Application Number:
  US11/312,638
• Publication Number:
  US 20070139637A1
• Time in Patent Office: 1,091 Days
• Field of Search: 355/53, 355/67, 355/71
• US Class Current: 355/67
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• 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

A lithographic apparatus comprising an array of individually controllable elements that modulates a beam of radiation and a projection system that projects the modulated beam onto the substrate. The individually controllable elements are provided with a compensation feature that is arranged to provide compensation radiation that substantially or at least partially cancels out unwanted radiation, such that the unwanted radiation is not projected by the projection system onto the substrate.

Claims

1. A lithographic apparatus, comprising:

an array of individually controllable elements that modulates a beam of radiation; and

a projection system that projects the modulated beam onto a substrate,

wherein the individually controllable elements are provided with a compensation feature that is shaped to provide compensation radiation within a given diffraction order that has substantially a same amplitude, but opposite phase, to diffracted radiation to substantially cancel out the diffracted radiation, such that the diffracted radiation is not projected by the projection system onto the substrate.

2. The apparatus of claim 1, wherein the array of individually controllable elements comprises an array of movable mirrors.

3. The apparatus of claim 2, wherein the compensation feature comprises a portion of the mirror that is recessed or raised with respect to the remainder of the mirror, such that radiation reflected from the portion has a phase that is different from radiation reflected from the remainder of the mirror.

4. The apparatus of claim 3, wherein a depth or height of the compensation feature, as compared with the remainder of the surface of the mirror, is one quarter of a wavelength of the beam of radiation.

5. The apparatus of claim 2, wherein a mirror in the array of mirrors has the compensation feature which comprises a step that extends across the mirror in a direction that is parallel to an axis of rotation of the mirror.

6. The apparatus of claim 5, wherein the step has a depth of one quarter of a wavelength of the beam of radiation.

7. The apparatus of claim 5, wherein the step bisects the axis of rotation of the mirror.

8. The apparatus of claim 2, wherein:

the movable mirrors are connected to posts; and

a compensation feature is provided on at least one of the posts.

9. The apparatus of claim 8, wherein the compensation feature comprises a step provided on at least one of the posts.

10. The apparatus of claim 1, wherein a size of the compensation feature is configured to perform the substantial or at least partial canceling out of the diffracted radiation.

11. The apparatus of claim 1, wherein an individually controllable element in the array of individually controllable elements is a mirror and the compensation feature is symmetric about a rotational axis of the mirror.

12. The apparatus of claim 1, wherein an individually controllable element in the array of individually controllable elements is a mirror and the compensation feature is located on, and extends to either side of, a rotational axis of the mirror.

13. The apparatus of claim 1, wherein the compensation feature comprises an array of raised and/or recessed portions.

14. An array of movable mirrors comprising:

a compensation feature that is shaped to provide compensation radiation within a given diffraction order that has substantially a same amplitude, but opposite phase, to diffracted radiation to substantially cancel out the diffracted radiation, the compensation feature comprising a portion of each of the mirrors that is recessed or raised with respect to a remainder of the mirror in the array of movable mirrors.

15. An array of movable mirrors, comprising:

a compensation feature that is shaped to provide compensation radiation within a given diffraction order that has substantially a same amplitude, but opposite phase, to diffracted radiation to substantially cancel out the diffracted radiation, the compensation feature comprising a step which extends transversely across each mirror in the array of movable mirrors.

16. A lithographic apparatus, comprising:

a supporting substrate that comprises a compensation feature;

an array of individually controllable elements that are coupled to the supporting substrate and that modulate a beam of radiation; and

a projection system that projects the modulated beam onto a substrate,

wherein the compensation feature provides compensation radiation that substantially or at least partially cancels out radiation reflected by the supporting substrate, such that the radiation reflected by the supporting substrate is not projected by the projection system onto the substrate.

17. A system, comprising:

a supporting substrate; and

an array of movable mirrors provided on the supporting substrate, the supporting substrate being provided with a compensation feature comprising a step that extends transversely across the supporting substrate.