Lithographic apparatus having double telecentric illumination

• US 20060017902A1
• Filed: 07/26/2004
• Published: 01/26/2006
• Est. Priority Date: 07/26/2004
• Status: Active Grant

• Current Assignee: ASML Holding NV
• Original Assignee: ASML Holding NV
• Inventors: Vladimirsky, Yuli, Rhyzhikov, Lev
• Granted Patent: US 7,227,613 B2
• Time in Patent Office: Days
• US Class Current: 355/67
• CPC Class Codes: G03F 7/70225 Optical aspects of catadioptric systems, i.e. comprising reflective and refractive elements
• 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

A system and method are used to pattern illumination to form one or more devices on a substrate using a reflecting system, a pattern generator that defines an objection plane, a projection system, and the substrate that defines an image plane. A reflecting portion of the reflecting system is substantially parallel to a reflecting portion of the pattern generator. The reflecting portion of the pattern generator patterns the illumination beam and directs the patterned illumination beam towards the substrate via the projection system. Based on the relationship of the reflecting system and the pattern generator, the illumination beam is telecentric proximate the object plane and the patterned illumination beam is telecentric proximate the image plane. Through use of a reflecting optic and not a transmissive optic to direct light between the illuminator and the projection system, illumination efficiency is increased and errors imparted on the illumination are decreased.

Claims

1. A system, comprising,

an illumination system that generates an illumination beam of radiation;

a reflecting system;

a pattern generator defining an object plane; and

a projection system,

wherein a reflecting portion of the reflecting system is substantially parallel to a reflecting portion of the pattern generator when reflecting portion of the pattern generator is in a default state, the reflecting portion of the pattern generator patterning the illumination beam and directing the patterned illumination beam to a substrate defining an image plane via the projection system, such that the illumination beam is telecentric proximate the object plane and the patterned illumination beam is telecentric proximate the image plane.

2. The system of claim 1, wherein the pattern generator comprises:

a plurality of controllable elements, each of the plurality of controllable elements having a reflecting surface adjustable in the default state to be substantially parallel to the reflecting portion of the reflecting system.

3. The system of claim 2, wherein each of the reflecting surfaces of the plurality of controllable elements is positionable at an angle with respect to the object plane.

4. The system of claim 2, further comprising:

a calibration system that positions elements in the plurality of controllable elements.

5. The system of claim 2, wherein the illumination beam is formed such that substantially all of the illumination beam interacts with the plurality of controllable elements.

6. The system of claim 1, further comprising

a plurality of pattern generators each including a one or more reflecting surfaces thereon,

wherein the reflecting portion of the reflecting system comprises a plurality of sections that are substantially parallel to the one or more reflecting surfaces in a default state on the plurality of pattern generators.

7. The system of claim 6, wherein the reflection portion reflects the illumination beam inwardly.

8. The system of claim 6, wherein the reflecting portion reflects the illumination beam outwardly.

9. The system of claim 6, wherein the reflecting portion reflects the illumination through a central opening of the object plane.

10. The system of claim 6, wherein the reflecting portion reflects the illumination beam through a peripheral opening of the object plane.

11. A lithography system, comprising:

an illuminating system that produces an illumination beam;

a dynamic pattern generator having a plurality of reflective controllable elements that patterns the illumination beam;

a reflector having a conical reflecting surface that is substantially parallel to respective reflecting surfaces of the plurality of reflective controllable elements in a default state; and

a projection system that directs the pattered illumination beam onto a substrate,

wherein the illumination beam is telecentric proximate an object plane and the pattered illumination beam is telecentric proximate an image plane.

12. The lithography system of claim 11, wherein the reflector directs the illumination beam outwardly towards the dynamic pattern generator.

13. The lithography system of claim 11, wherein the reflector directs the illumination beam through a peripheral opening in the object plane.

14. The lithography system of claim 11, further comprising:

a calibration system that is used to position each element in the plurality of controllable elements such that they are substantially parallel in the default state to the conical reflecting surface.

15. A lithography system, comprising:

an illuminating system that produces an illumination beam;

a dynamic pattern generator having a plurality of reflective controllable elements that patterns the illumination beam;

a reflector having a pyramid shaped reflecting surface that is substantially parallel to respective reflecting surfaces of the plurality of reflective controllable elements in a default state; and

a projection system that directs the pattered illumination beam onto a substrate,

wherein the illumination beam is telecentric proximate an object plane and the pattered illumination beam is telecentric proximate an image plane.

16. The lithography system of claim 15, wherein the reflector directs the illumination beam outwardly towards the dynamic pattern generator.

17. The lithography system of claim 15, wherein the reflector directs the illumination beam through a peripheral opening in the object plane.

18. The lithography system of claim 15, further comprising:

a calibration system that is used to position each element in the plurality of controllable elements such that they are substantially parallel in the default state to the pyramid shaped reflecting surface.

19. A lithography system, comprising:

an illuminating system that produces an illumination beam;

a plurality of dynamic pattern generators each having a plurality of reflective controllable elements that pattern the illumination beam;

a reflector whose respective reflecting sections are substantially parallel to reflecting surfaces of the plurality of reflective controllable elements in a default state; and

a projection system that directs the pattered illumination beam onto a substrate,

wherein the illumination beam is telecentric proximate an object plane and the pattered illumination beam is telecentric proximate an image plane.

20. The lithography system of claim 19, wherein the reflector reflects the illumination beam inwardly towards the dynamic pattern generator.

21. The lithography system of claim 19, wherein the reflector reflects the illumination beam through a central opening in the object plane.

22. The lithography system of claim 19, further comprising:

a calibration system that positions elements in the plurality of controllable elements such that they are substantially parallel in the default state to the reflector.

23. A method of making a device, comprising:

(a) reflecting an illumination beam from a reflecting system towards a pattern generator that defines an object plane;

(b) patterning the illumination beam using the pattern generator;

(c) directing the patterned illumination beam using a projection system onto a substrate that defines an image plane and on which the device is formed; and

(d) positioning a reflecting portion of the reflecting system substantially parallel to a reflecting portion of the pattern generator when the pattern generator is in a default state, the reflecting portion of the pattern generator patterning the illumination beam and directing the patterned illumination beam to the substrate, such that the illumination beam is telecentric proximate the object plane and the patterned illumination beam is telecentric proximate the image plane.

24. The method of claim 23, wherein step (b) comprises:

using a plurality of controllable elements each having a reflecting surface adjustable in the default state to be substantially parallel to a reflecting portion of the reflecting system.

25. The method of claim 24, wherein each of the reflecting surfaces of the plurality of controllable elements is positionable at an angle with respect to the object plane.

26. The method of claim 24, further comprising:

(e) using a calibration method to position elements in the plurality of controllable elements.

27. The method of claim 23, wherein step (a) comprises:

forming the illumination beam such that substantially all of the illumination beam interacts with the plurality of controllable elements.

28. The method of claim 23, wherein step (a) comprises:

using a plurality of pattern generators as the pattern generator, each including a plurality of controllable elements having a reflective surface; and

adjusting each of the plurality of controllable elements, such that reflection sections on the reflecting portion are substantially parallel to the reflecting surfaces of the controllable elements when the controllable elements are in the default state.

29. The method of claim 28, wherein the reflecting sections reflect the illumination beam inwardly.

30. The method of claim 28, wherein the reflecting sections surfaces reflect the illumination beam outwardly.

31. The method of claim 28, wherein the reflecting sections reflect the illumination through a central opening of the object plane.

32. The method of claim 28, wherein the reflecting sections reflect the illumination beam through a peripheral opening of the object plane.