SPATIAL LIGHT MODULATION ELEMENTS, METHOD FOR MANUFACTURING SAME, AND SPATIAL LIGHT MODULATORS AND EXPOSURE APPARATUS COMPRISING SAME

• US 20140168751A1
• Filed: 02/19/2014
• Published: 06/19/2014
• Est. Priority Date: 08/25/2011
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Suzuki, Yoshihiko, Suzuki, Junji, Konishi, Hiroshi
• Granted Patent: US 9,217,860 B2
• Time in Patent Office: Days
• US Class Current: 359/291
• CPC Class Codes: B81B 3/00 Devices comprising flexible or deformable elements, e.g. comprising elastic tongues or membranes B81B5/00 takes precedence
• CPC Class Codes: G02B 26/08 for controlling the direction of light in light guides G02B6/35
• 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: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling

Abstract

Provided is a spatial light modulation element comprising a substrate; a flat portion that is movable relative to the substrate; a flat board attached to the flat portion; and a dielectric film that is formed on a surface of the flat board opposite the surface on which the flat portion is attached, and reflects incident light. In the spatial light modulation element the dielectric film may include two or more types of dielectric layers that are repeatedly layered in an alternating manner, such that adjacent layers have different refractive indexes from each other. Furthermore, the dielectric film may be formed by alternately layering an Al₂O₃ film and a SiO₂ film.

Claims

1. A spatial light modulation element comprising:

a substrate;

a flat portion that is movable relative to the substrate;

a flat board attached to the flat portion; and

a dielectric film that is formed on a surface of the flat board opposite the surface on which the flat portion is attached, and reflects incident light.

2. The spatial light modulation element according to claim 1, wherein

the dielectric film includes two or more types of dielectric layers that are repeatedly layered in an alternating manner, such that adjacent layers have different refractive indexes from each other.

3. The spatial light modulation element according to claim 1, wherein

the dielectric film is formed by alternately layering an Al₂O₃ film and a SiO₂ film.

4. The spatial light modulation element according to claim 3, wherein

a surface of the flat portion includes a SiN_x thin film.

5. The spatial light modulation element according to claim 1, wherein

thickness of the flat board is greater than thickness of the flat portion.

6. The spatial light modulation element according to claim 5, wherein

the flat board is formed by thinning a bulk material.

7. The spatial light modulation element according to claim 1, wherein

an effective reflective region of the flat board includes a single flat surface.

8. The spatial light modulation element according to claim 1, wherein

the substrate further includes a movable section that moves the flat portion and a connecting section that distances the flat portion from the movable section.

19. A spatial light modulator comprising a plurality of the spatial light modulation elements according to claim 1.

20. An exposure apparatus comprising the spatial light modulator according to claim 19.

9. A spatial light modulation element comprising:

a substrate;

a flat portion that pivots relative to the substrate;

a dielectric multilayer film that pivots together with the flat portion, includes a plurality of dielectric layers that are layered in an alternating manner, and reflects incident light; and

a protective layer that includes the same material as one of the dielectric layers, is thicker than this dielectric layer, and covers at least a portion of a surface of the one dielectric layer that is opposite the flat portion.

11. The spatial light modulation element according to claim 9, wherein

the protective layer is a barrier against at least one of fluorine, oxygen, and a compound including at least one of fluorine and oxygen.

12. The spatial light modulation element according to claim 9, wherein

the protective layer covers the dielectric multilayer film up to side surfaces thereof.

13. The spatial light modulation element according to claim 9, wherein

the protective layer includes Al₂O₃.

14. The spatial light modulation element according to claim 9, wherein

the protective layer has a thickness that is an integer multiple of a half-wavelength with respect to a wavelength of the incident light reflected by the dielectric multilayer film.

21. A spatial light modulator comprising a plurality of the spatial light modulation elements according to claim 9.

22. An exposure apparatus comprising the spatial light modulator according to claim 21.

10. A spatial light modulation element comprising:

a substrate;

a flat portion that pivots relative to the substrate;

a dielectric multilayer film that pivots together with the flat portion, includes a plurality of dielectric layers that are layered in an alternating manner, and reflects incident light; and

a protective layer that includes the same material as one of the dielectric layers and covers side surfaces of the dielectric multilayer film.

15. The spatial light modulation element according to claim 10, wherein

the protective layer is a barrier against at least one of fluorine, oxygen, and a compound including at least one of fluorine and oxygen.

16. The spatial light modulation element according to claim 10, wherein

the protective layer covers the dielectric multilayer film up to side surfaces thereof.

17. The spatial light modulation element according to claim 10, wherein

the protective layer includes Al₂O₃.

18. The spatial light modulation element according to claim 10, wherein

the protective layer has a thickness that is an integer multiple of a half-wavelength with respect to a wavelength of the incident light reflected by the dielectric multilayer film.

23. A spatial light modulator comprising a plurality of the spatial light modulation elements according to claim 10.

24. An exposure apparatus comprising the spatial light modulator according to claim 23.

25. A method of manufacturing a spatial light modulation element, comprising:

preparation of preparing a substrate and a flat portion that is movable relative to the substrate;

deposition of depositing a dielectric film that reflects incident light on one surface of a flat board; and

attachment of attaching the flat portion to a side of the flat board on which the dielectric film is not formed.

26. The manufacturing method according to claim 25, wherein

in the deposition, the flat board is a bulk material, and

the manufacturing method further includes thinning of thinning the bulk material, before the attachment and after the deposition.

27. The manufacturing method according to claim 26, further comprising annealing the flat board on which the dielectric film is deposited, after the deposition and before the thinning.

28. The manufacturing method according to claim 25, further comprising patterning the flat board, before the attachment.

29. The manufacturing method according to claim 25, wherein

the flat portion is formed by depositing a thin film.

41. A spatial light modulation element manufactured according to the manufacturing method of claim 25.

42. A spatial light modulator comprising a plurality of the spatial light modulation elements according to claim 41.

43. An exposure apparatus comprising the spatial light modulator according to claim 42.

30. A method of manufacturing a spatial light modulation element, comprising:

formation of forming a support section and a flat portion that pivotally supports the support section, on a substrate;

formation of forming a dielectric multilayer film that reflects incident light on one surface of the flat portion, in a state where at least one of the support section and the flat portion is in contact with a sacrificial layer;

covering of covering at least a portion of a surface of the dielectric multilayer film with a protective layer that is resistant to an etchant used to remove the sacrificial layer, with the sacrificial layer being present; and

removal of removing the sacrificial layer using the etchant, with the protective layer being present.

31. The manufacturing method according to claim 30, further comprising removing the protective layer after the removal of the sacrificial layer.

32. The manufacturing method according to claim 30, further comprising forming the flat portion using the sacrificial layer as a base.

33. The manufacturing method according to claim 30, further comprising patterning the protective layer, with the sacrificial layer being present.

34. The manufacturing method according to claim 33, further comprising patterning the flat portion with the patterned protective layer serving as a mask.

35. The manufacturing method according to claim 30, comprising:

patterning the dielectric multilayer film; and

forming a protective layer that covers at least side ends of the patterned dielectric multilayer film, with the sacrificial layer being present.

36. The manufacturing method according to claim 35, comprising forming the protective layer to cover all surfaces exposed by the dielectric multilayer film.

37. The manufacturing method according to claim 30, wherein

the protective layer is formed after the flat portion is patterned.

38. The manufacturing method according to claim 30, comprising reducing residual stress of the dielectric multilayer film before formation of the protective layer.

39. The manufacturing method according to claim 30, comprising forming a topmost dielectric layer in the dielectric multilayer film from a material that is resistant to the etchant, and using the topmost dielectric layer as the protective layer.

40. The manufacturing method according to claim 39, wherein

the topmost dielectric layer is thicker than other dielectric layers forming the dielectric multilayer film.

44. A spatial light modulation element manufactured according to the manufacturing method of claim 30.

45. A spatial light modulator comprising a plurality of the spatial light modulation elements according to claim 44.

46. An exposure apparatus comprising the spatial light modulator according to claim 45.