Surface position detecting system and device manufacturing method using the same

• US 6,040,909 A
• Filed: 05/01/1998
• Issued: 03/21/2000
• Est. Priority Date: 05/02/1997
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ohsaki, Yoshinori, Yoshii, Minoru, Hasegawa, Masanobu
• Primary Examiner(s): HANTIS, KAREN
• Application Number:
  US09/070,741
• Time in Patent Office: 690 Days
• Field of Search: 356/399-401, 356/375, 356/376, 250/548, 250/559.3, 250/559.2, 355/53
• US Class Current: 356/614
• CPC Class Codes: G03F 7/70691 Handling of masks or workpieces
• CPC Class Codes: G03F 9/7026 Focusing

Abstract

A detecting system for detecting positional information related to a surface of an object. The detecting system includes a variable pattern generator for projecting an arbitrary pattern image on the surface of the object, a light projecting optical system for projecting a pattern, defined by the variable pattern generator, to the surface of the object along an oblique direction, a light receiving optical system for directing light from an image of the pattern and a light receiving element for detecting the light directed by the light receiving optical system. Surface position information about the surface of the object is detected on the basis of the detection by the light receiving element.

Claims

1. A detecting system for detecting positional information related to a surface of an object, said detecting system comprising:

a variable pattern generator for projecting an arbitrary pattern image on the surface of the object;

a light projecting optical system for projecting a pattern, defined by said variable pattern generator, to the surface of the object along an oblique direction;

a light receiving optical system for directing light from an image of the pattern; and

a light receiving element for detecting the light directed by said light receiving optical system, wherein surface position information about the surface of the object is detected on the basis of the detection by said light receiving element.

2. A system according to claim 1, further comprising a second pattern generator disposed at a plane where the image of the pattern is re-imaged, wherein said light receiving optical system includes a movable mirror, said light receiving element detects a change, with respect to time, in quantity of light emitted by said second pattern generator during motion of said movable mirror, and the surface position information about the surface of the object is detected on the basis of the detected change in light quantity with respect to time.

3. A system according to claim 2, wherein each of the two pattern generators comprise a DMD.

4. A system according to claim 2, wherein the two pattern generators produce the patterns or analogous patterns.

5. A system according to claim 1, wherein said variable pattern generator comprises a DMD.

6. A system according to claim 1, wherein said variable pattern generator comprises an SLM.

7. A system according to claim 1, wherein said variable pattern generator comprises a liquid crystal device.

8. A system according to claim 1, wherein said variable pattern generator comprises a surface light emitting device.

9. A system according to claim 1, wherein said light receiving element detects positional information about the image of the pattern as re-imaged upon a predetermined plane, and the surface position information about the surface of the object is detected on the basis of that positional information.

10. A system according to claim 1, further comprising conveying means for conveying the object in a direction substantially along the surface of the object, wherein said variable pattern generator changes the pattern to be formed, in accordance with conveyance by said conveying means.

11. An exposure apparatus for projecting a circuit pattern of a reticle onto a photosensitive substrate, said apparatus comprising:

a projection optical system for performing the pattern projection;

surface position information detecting means for detecting positional information about the surface of the photosensitive substrate, said surface position information detecting means comprising (i) a variable pattern generator for projecting an arbitrary pattern image on the surface of the substrate, (ii) a light projecting optical system for projecting a pattern, defined by said variable pattern generator, to the surface of the substrate along an oblique direction, (iii) a light receiving optical system for directing light from an image of the pattern, and (iv) a light receiving element for detecting the light directed by said light receiving optical system, wherein surface position information about the surface of the substrate is detected on the basis of the detection by said light receiving element; and

a control system for controlling a position of the photosensitive substrate with respect to an optical axis of said projection optical system, in accordance with the detection by said surface position information detecting means.

12. An apparatus according to claim 11, further comprising a second pattern generator disposed at a plane where the image of the pattern is re-imaged, wherein said light receiving optical system includes a movable mirror, said light receiving element detects a change, with respect to time, in quantity of light emitted by said second pattern generator during motion of said movable mirror, and the surface position information about the surface of the substrate is detected on the basis of the detected change in light quantity with respect to time.

13. An apparatus according to claim 12, wherein each of the two pattern generators comprise a DMD.

14. An apparatus according to claim 12, wherein the two pattern generators produce the patterns or analogous patterns.

15. An apparatus according to claim 11, wherein said variable pattern generator comprises a DMD.

16. An apparatus according to claim 11, wherein said variable pattern generator comprises an SLM.

17. An apparatus according to claim 11, wherein said variable pattern generator comprises a liquid crystal device.

18. An apparatus according to claim 11, wherein said variable pattern generator comprises a surface light emitting device.

19. An apparatus according to claim 11, wherein said light receiving element detects positional information about the image of the pattern as re-imaged upon a predetermined plane, and the surface position information about the surface of the substrate is detected on the basis of that positional information.

20. An apparatus according to claim 11, further comprising conveying means for conveying the substrate in a direction substantially along the surface of the substrate, wherein said variable pattern generator changes the pattern to be formed, in accordance with conveyance by said conveying means.

21. An electronic device manufacturing method, comprising the steps of:

projecting a pattern, defined by a variable pattern generator, by projecting an arbitrary pattern image on the surface of a photosensitive substrate, with the variable pattern generator, in a direction inclined with respect to an optical axis of a projection optical system, whereby an image of the pattern is formed on the photosensitive substrate;

directing light from the image of the pattern to a light receiving element;

detecting the directed light, with the light receiving element;

controlling the position of the photosensitive substrate with respect to an optical axis direction of the projection optical system, on the basis of the detection;

exposing the position controlled photosensitive substrate to a circuit pattern through the projection optical system;

developing the exposed photosensitive substrate; and

forming a circuit on the developed substrate, whereby a device is produced.

22. A detecting system for detecting positional information related to a surface of an object, said detecting system comprising:

a light projecting optical system for projecting light to the surface of the object along an oblique direction, wherein a pattern image is formed on the surface of the object;

a light receiving optical system for directing light from the pattern image;

a light receiving element for detecting the light directed by said light receiving optical system, wherein surface position information about the surface of the object is detected on the basis of the detection by said light receiving element;

conveying means for moving the object in a direction approximately along the surface of the object; and

a variable pattern generator for projecting an arbitrary pattern image on the surface of the object, wherein said variable pattern generator projects an arbitrary pattern in accordance with the conveyance through said conveying means.

23. A system according to claim 22, further comprising a second pattern generator disposed at a plane where the image of the pattern is re-imaged, wherein said light receiving optical system includes a movable mirror, said light receiving element detects a change, with respect to time, in quantity of light emitted by said second pattern generator during motion of said movable mirror, and the surface position information about the surface of the object is detected on the basis of the detected change in light quantity with respect to time.

24. A system according to claim 23, wherein each of the two pattern generators comprise a DMD.

25. A system according to claim 23, wherein the two pattern generators produce the patterns or analogous patterns.

26. A system according to claim 22, wherein said variable pattern generator comprises a DMD.

27. A system according to claim 22, wherein said variable pattern generator comprises an SLM.

28. A system according to claim 22, wherein said variable pattern generator comprises a liquid crystal device.

29. A system according to claim 22, wherein said variable pattern generator comprises a surface light emitting device.

30. A system according to claim 22, wherein said variable light receiving element detects positional information about the image of the pattern as re-imaged upon a predetermined plane, and the surface position information about the surface of the object is detected on the basis of that positional information.

31. A system according to claim 22, further comprising conveying means for conveying the object in a direction substantially along the surface of the object, wherein said variable pattern generator changes the pattern to be formed, in accordance with conveyance by said conveying means.

32. An exposure apparatus for projecting a circuit pattern of a reticle onto a photosensitive substrate, said apparatus comprising:

a projection optical system for performing the projection exposure;

conveying means for moving the photosensitive substrate in a direction orthogonal to an optical axis of said projection optical system;

surface position information detecting means for detecting positional information about the surface of the photosensitive substrate, said surface position information detecting means comprising (i) a variable pattern generator for projecting an arbitrary pattern image on the photosensitive substrate, said variable pattern generator projecting an arbitrary pattern image in accordance with the conveyance through said conveying means, (ii) a light projecting optical system for projecting light to the surface of the photosensitive substrate in a direction inclined with respect to the optical axis of said projection optical system, wherein the pattern image is formed on the photosensitive substrate surface through the projection, (iii) a light receiving optical system for directing light from the pattern image, and (iv) a light receiving element for detecting the light directed by said light receiving optical system, wherein surface position information about the surface of the object is detected on the basis of the detection by said light receiving element; and

a control system for controlling a position of the photosensitive substrate with respect to the optical axis of said projection optical system, in accordance with the detection by said surface position detecting means.

33. An apparatus according to claim 32, further comprising a second pattern generator disposed at a plane where the image of the pattern is re-imaged, wherein said light receiving optical system includes a movable mirror, said light receiving element detects a change, with respect to time, in quantity of light emitted by said second pattern generator during motion of said movable mirror, and the surface position information about the surface of the substrate is detected on the basis of the detected change in light quantity with respect to time.

34. An apparatus according to claim 33, wherein each of the two pattern generators comprise a DMD.

35. A system according to claim 33, wherein the two pattern generators produce the patterns or analogous patterns.

36. An apparatus according to claim 32, wherein said variable pattern generator comprises a DMD.

37. An apparatus according to claim 32, wherein said variable pattern generator comprises an SLM.

38. An apparatus according to claim 32, wherein said variable pattern generator comprises a liquid crystal device.

39. An apparatus according to claim 32, wherein said variable pattern generator comprises a surface light emitting device.

40. An apparatus according to claim 32, wherein said light receiving element detects positional information about the image of the pattern as re-imaged upon a predetermined plane, and the surface position information about the surface of the substrate is detected on the basis of that positional information.

41. An apparatus according to claim 32, further comprising conveying means for conveying the substrate in a direction substantially along the surface of the substrate, wherein said variable pattern generator changes the pattern to be formed, in accordance with conveyance by said conveying means.

42. An electronic device manufacturing method, comprising the steps of:

conveying a photosensitive substrate in a direction perpendicular to an optical axis of a projection optical system;

providing a variable pattern generator for projecting an arbitrary pattern image on the photosensitive substrate, wherein the variable pattern generator projects an arbitrary pattern image in accordance with the conveyance;

projecting light onto the surface of the photosensitive substrate in a direction inclined with respect to the optical axis of the projection optical system, whereby the pattern image is formed on the photosensitive substrate;

directing light from the pattern image to a light receiving element;

detecting the directed light, with the light receiving element;

controlling the position of the photosensitive substrate with respect to an optical axis direction of the projection optical system, on the basis of the detection;

exposing the position controlled photosensitive substrate to a circuit pattern through the projection optical system;

developing the exposed photosensitive substrate; and

forming a circuit on the developed substrate, whereby a device is produced.