Micro-electro-mechanical-system (MEMS) mirror device

• US 20020071169A1
• Filed: 02/01/2000
• Published: 06/13/2002
• Est. Priority Date: 02/01/2000
• Status: Abandoned Application

• Current Assignee: CALIENT Technologies, Inc.
• Original Assignee: CALIENT Technologies, Inc.
• Inventors: Sink, Robert Kehl, Lee, Seung Bok, Bowers, John Edward, MacDonald, Noel, Helkey, Roger Jonathan, Corbalis, Charles
• Application Number:
  US09/497,270
• Publication Number:
  US 20020071169A1
• Time in Patent Office: Days
• US Class Current: 359/291
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 3/004 Angular deflection
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A micro-electro-mechanical-system (MEMS) mirror device and methods for fabricating the same allow for a large range of angular motion for a center mirror component. The large range of angular motion for a center mirror component is dictated simply by a thickness of a substrate used or a thickness of a thick film used in making a support structure to support the center mirror component. The MEMS mirror device and methods for fabricating the same allow a large number mirror devices to be fabricated on a substrate. The MEMS mirror device includes a substrate. Electrodes are formed supported by the substrate. A support structure is formed adjacent to the electrodes. A hinge pattern and a mirror pattern having a center mirror component are formed such that the support structure supports the hinge pattern and mirror pattern. The support structure also supports the hinge pattern and mirror pattern such that a bottom surface of the center mirror component in a stationary non-rotating position is capable of exceeding a height of 50 μm above the electrodes.

Claims

1. A micro-electro-mechanical-system (MEMS) mirror device, comprising:

a substrate;

electrodes supported by the substrate;

a support structure formed adjacent to the electrodes;

a hinge pattern and a mirror pattern having a center mirror component such that the support structure supports the hinge pattern and mirror pattern; and

wherein the support structure supports the hinge pattern and mirror pattern such that a bottom surface of the center mirror component in a stationary non-rotating position is capable of exceeding a height of 50 μ

m above the electrodes.

2. The MEMS mirror device of claim 1, wherein the center mirror component is capable of having an angular range of motion exceeding 20 degrees with respect to an axis.

3. The MEMS mirror device of claim 1, wherein the support structure is photosensitive glass, silicon, or plated metal.

4. The MEMS mirror device of claim 1, wherein the plated metal is nickel Ni, Copper Cu, or gold Au.

5. The MEMS mirror device of claim 1, wherein the support structure defines holes such that the holes are approximately centered below the center mirror component.

6. The MEMS mirror device of claim 1, further comprising:

a wiring pattern coupled with the electrodes; and

an insulation layer insulating the wiring pattern and electrodes.

7. The MEMS mirror device of claim 1, wherein the mirror pattern includes a frame pattern such that the hinge pattern supports the frame pattern.

8. The MEMS mirror device of claim 1, wherein the mirror pattern includes a frame pattern and a mirror component such that the hinge pattern supports the frame pattern and mirror component.

9. The MEMS mirror device of claim 1, wherein the mirror pattern includes at least one layer.

10. The MEMS mirror device of claim 9, wherein the mirror pattern includes a gold Au metal layer, an aluminum Al metal layer, or a copper Cu layer.

11. The MEMS mirror device of claim 9, wherein the mirror pattern includes:

a first metal layer;

a support layer formed on the first metal layer; and

a second metal layer formed on the support layer.

12. The MEMS mirror device of claim 11, wherein the first and second metal layers are a gold Au metal layer, aluminum Al metal layer, or copper Cu metal layer.

13. The MEMS mirror device of claim 11, wherein the support layer is a silicon dioxide SiO₂ layer, silicon nitride Si_xN_y layer, polysilicon layer, silicon oxynitride Si_xO_yN_z layer, or polymer layer.

14. The MEMS mirror device of claim 1, wherein the center mirror component is used for optical switching.

15. The MEMS mirror device of claim 1, wherein the center mirror component is a component for scanning systems, printing systems, and display systems.

17. The fabrication method of claim 16, wherein the substrate is a photosensitive glass substrate.

18. The fabrication method of claim 17, wherein exposing selectively a substrate exposes selectively the photosensitive glass substrate to form exposed regions such that the center mirror component is approximately centered of the exposed regions.

19. The fabrication method of claim 18, further comprising:

polishing the photo sensitive glass substrate after exposing selectively the photo sensitive glass substrate to retain planarity and remove any materials formed thereon.

20. The fabrication method of claim 18, wherein removing portions of the substrate includes:

etching selectively using an etching solution the exposed regions of the photosensitive glass substrate.

21. The fabrication method of claim 20, wherein the etching solution is hydro-fluoric HF acid and wherein the HF acid etches more rapidly in the exposed regions than in the unexposed regions.

22. The fabrication method of claim 20, wherein etching selectively includes:

forming a protection layer over the mirror pattern and hinge pattern such that portions of the photosensitive glass substrate are exposed to allow the etching solution to reach the exposed regions of the photosensitive glass substrate; and

depositing the etching solution over the photosensitive glass such that the etching solution reaches the exposed regions of the photosensitive glass to form the support structure from the unexposed regions of the photosensitive glass.

23. The fabrication method of claim 22, further including:

removing the protection layer.

24. The fabrication method of claim 16, wherein forming the mirror pattern forms a frame pattern such that the hinge pattern supports the frame pattern.

25. The fabrication method of claim 16, wherein forming the mirror pattern forms a frame pattern and a mirror component such that the hinge pattern supports the frame pattern and mirror component.

26. The fabrication method of claim 16, wherein a thickness of the support structure is capable of exceeding a thickness of 50 μ

m.

27. The fabrication method of claim 16, wherein the mirror pattern includes at least one layer.

28. The fabrication method of claim 27, wherein the mirror pattern includes a gold Au metal layer, an aluminum Al metal layer, or a copper cu metal layer.

30. The fabrication method of claim 29, wherein the first and second metal layers are a gold Au metal layer, aluminum Al metal layer, or copper Cu metal layer.

31. The fabrication method of claim 29, wherein the support layer is a silicon dioxide SiO₂ layer, silicon nitride Si_xN_y layer, polysilicon layer, silicon oxynitride Si_xO_yN_z layer, or polymer layer.

32. The fabrication method of claim 16, further comprising:

forming a wiring pattern such that the wiring pattern is coupled with the electrodes;

forming an insulation layer such that the insulation layer insulates the wiring pattern and electrodes.

16. A micro-electro-mechanical-system (MEMS) mirror device fabrication method, comprising:

exposing selectively a substrate to form exposed regions and unexposed regions;

forming electrodes supported by the substrate;

forming a mirror pattern having a center mirror component and a hinge pattern supported by the substrate; and

removing portions of the substrate in the exposed regions to form a support structure from the unexposed regions such that the support structure supports the mirror pattern and hinge pattern.

29. The fabrication method of 27, wherein forming a mirror pattern includes:

forming a first metal layer;

forming a support layer on the first metal layer; and

forming a second metal layer on the support layer.

33. A micro-electro-mechanical-system (MEMS) mirror device fabrication method, comprising:

forming a release layer on a first substrate;

forming a mirror pattern having a center mirror component and a hinge pattern supported by the release layer;

forming electrodes supported by a second substrate;

forming a support structure;

attaching the first substrate with the second substrate using the support structure;

removing the first substrate and the release layer such that the support structure supports the hinge pattern and mirror pattern.

34. The fabrication method of claim 33, wherein forming a support structure forms the support structure such that the support structure is supported by the second substrate.

35. The fabrication method of claim 34, wherein forming a support structure includes:

forming a bond with a topside of the support structure with the hinge pattern supported by the first substrate such that the first substrate is attached with the second substrate.

36. The fabrication method of claim 33, wherein forming a support structure forms the support structure such that the support structure is supported by the first substrate.

37. The fabrication method of claim 36, wherein forming a support structure includes:

forming a bond with a topside of the support structure with the second substrate such that first substrate is attached with the second substrate.

38. The fabrication method of claim 33, wherein forming the support structure uses a thick patterned film.

39. The fabrication method of claim 38, wherein forming the support structure uses an electroless, electro-plating, or a sputtering process with the thick patterned film to form the support structure.

40. The fabrication method of claim 39, wherein the thickness of the thick patterned film dictates the thickness of the support structure.

41. The fabrication method of claim 40, wherein forming the support structure uses nickel Ni, copper Cu, gold Au, or aluminum Al.

42. The fabrication method of claim 33, wherein the release layer is a polymer layer, oxide layer, or a nitride layer.

43. The fabrication method of claim 42, wherein removing the first substrate and release layer includes:

etching away the first substrate using an etching solution; and

applying oxygen plasma to react with the release layer such that the release layer is removed from the mirror pattern.

44. The fabrication method of claim 42, wherein removing the release layer includes:

etching away the release layer such that the release layer is removed from the mirror pattern.

45. The fabrication method of claim 33, wherein the first substrate is a silicon substrate, glass substrate, or borosilicate glass substrate.

46. The fabrication method of claim 33, wherein forming a mirror pattern forms a frame pattern supported by the release layer.

47. The fabrication method of claim 33, wherein forming a mirror pattern forms a frame pattern and a mirror component supported by the release layer.

48. The fabrication method of claim 33, wherein the mirror pattern includes at least one layer.

49. The fabrication method of claim 48, wherein the mirror pattern includes a gold Au metal layer, an aluminum Al metal layer, or a copper Cu metal layer.

50. The fabrication method of claim 48, wherein forming a mirror pattern includes:

forming a first metal layer on the release layer;

forming a support layer on the first metal layer; and

forming a second metal layer on the support layer.

51. The fabrication method of claim 50, wherein the first and second metal layers are a gold Au metal layer, aluminum Al metal layer, or copper Cu metal layer.

52. The fabrication method of claim 51, wherein the support layer is silicon dioxide SiO₂ layer, silicon nitride Si_xN_y layer, polysilicon layer, silicon oxynitride Si_xO_yN_z layer, or polymer layer.

53. The fabrication method of claim 33, further comprising:

forming a wiring pattern such that the wiring pattern is coupled with the electrodes; and

forming an insulation layer insulating the wiring pattern and electrodes.

54. A micro-electro-mechanical-system (MEMS) mirror device fabrication method, comprising:

forming a release layer on a first substrate;

forming a mirror pattern having a center mirror component and a hinge pattern supported by the release layer;

forming electrodes supported by a second substrate;

forming a support structure using a third substrate;

attaching the first substrate with the second substrate using the support structure;

removing the first substrate and release layer.

55. The fabrication method of claim 54, wherein the release layer is a polymer layer, oxide layer, or a nitride layer.

56. The fabrication method of claim 55, wherein removing the first substrate and release layer includes:

etching away the first substrate using an etching solution; and

applying oxygen plasma to react with the release layer such that the release layer is removed from the mirror pattern.

57. The fabrication method of claim 55, wherein removing the release layer includes:

etching away the release layer such that the release layer is removed from the mirror pattern.

58. The fabrication method of claim 54, wherein forming a mirror pattern forms a frame pattern supported by the release layer.

59. The fabrication method of claim 54, wherein forming a mirror pattern forms a frame pattern and a mirror component supported by the release layer.

60. The fabrication method of claim 54, wherein the mirror pattern includes at least one layer.

61. The fabrication method of claim 60, wherein the mirror pattern includes a gold Au metal layer, an aluminum Al metal layer, or a copper Cu metal layer.

62. The fabrication method of claim 60, wherein forming a mirror pattern includes:

forming a first metal layer;

forming a support layer on the first metal layer; and

forming a second metal layer on the support layer.

63. The fabrication method of claim 62, wherein the first and second metal layers are a gold Au metal layer, aluminum Al metal layer, or copper Cu metal layer.

64. The fabrication method of claim 62, wherein the support layer is silicon dioxide SiO₂ layer, silicon nitride Si_xN_y layer, polysilicon layer, silicon oxynitride Si_xO_yN_z layer, or polymer layer.

65. The fabrication method of claim 54, wherein the third substrate is a silicon substrate or a photosensitive glass substrate.

66. The fabrication method of claim 65, wherein forming a support structure includes:

exposing selectively the photosensitive glass substrate to form exposed regions and unexposed regions in the photosensitive glass substrate; and

removing portions of the photosensitive glass substrate in the exposed regions to form the support structure from the unexposed regions such that the support structure supports the hinge pattern and mirror pattern.

67. The fabrication method of claim 65, wherein forming a support structure includes:

etching deep holes in the silicon substrate such that the remaining portions of the silicon substrate form the support structure.

68. The fabrication method of claim 54, wherein a thickness of the third substrate dictates the thickness of the support structure, and wherein the thickness of the support structure is capable of exceeding a thickness of 50 μ

m.

69. The fabrication method of claim 54, further comprising:

forming a wiring pattern such that the wiring pattern is coupled with the electrodes; and

forming an insulation layer insulating the wiring pattern and electrodes.

70. A micro-electro-mechanical-system (MEMS) mirror device fabrication method, comprising:

forming electrodes supported by a first substrate;

removing selectively portions of a second substrate on a bottom side;

removing selectively portions of the second substrate on a topside to form a mirror pattern, frame pattern, hinge pattern, and support structure; and

attaching the first substrate with the second substrate.

71. The fabrication method of claim 70, wherein the second substrate is a silicon substrate or a single-crystal silicon substrate.

72. The fabrication method of claim 70, wherein removing selectively portions of a second substrate on a bottom side includes:

etching selectively the bottom side of the second substrate using an reactive ion etching RIE process, wet etch process, or a laser ablation process.

73. The fabrication method of claim 70, further comprising:

forming at least one layer on the mirror.

74. The fabrication method of claim 73, wherein the at least one layer is a gold Au metal layer, aluminum Al metal layer, or a copper Cu metal layer.

75. The fabrication method of claim 70, further comprising:

forming at least one layer on the mirror and frame pattern.

76. The fabrication method of claim 75, wherein the at least one layer is a gold Au metal layer, aluminum Al metal layer, or a copper Cu metal layer.

77. The fabrication method of claim 70, wherein the hinge pattern is formed such that the hinge pattern has a smaller thickness than the mirror and frame pattern.

78. The fabrication method of claim 77, wherein removing selectively portions of the second substrate on a topside to form the hinge pattern includes:

releasing the hinge pattern from the second substrate such that the hinge pattern is supported by the support structure.

79. The fabrication method of claim 78, wherein removing selectively portions of the second substrate on a topside to form the mirror and the frame pattern includes:

releasing the mirror and the frame pattern from the second substrate such that frame pattern is supported by the hinge pattern and the mirror is supported by the frame pattern.

80. The fabrication method of claim 70, wherein the hinge pattern, the mirror, and frame pattern have the same thickness.

81. The fabrication method of claim 80, wherein removing selectively portions of the second substrate on a topside to form the hinge pattern, mirror, and frame pattern include:

releasing the hinge pattern, mirror, and frame pattern from the second substrate such that the hinge pattern is supported by the support structure, the frame pattern is supported by the hinge pattern, and the mirror is supported by the frame pattern.

82. The fabrication method of claim 70, wherein a thickness of the support structure is capable of exceeding a thickness of 50 μ

m.

83. The fabrication method of claim 70, further comprising:

forming a wiring pattern such that the wiring pattern is coupled with the electrodes; and

forming an insulation layer insulating the wiring pattern and electrodes.