Method of making prestructure for MEMS systems

• US 20060079048A1
• Filed: 05/20/2005
• Published: 04/13/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Sampsell, Jeffrey B.
• Granted Patent: US 7,527,995 B2
• Time in Patent Office: Days
• US Class Current: 438/222
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 2203/0361 Tips, pillars
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26

Abstract

A method of making an interferometric modulator element includes forming at least two posts, such as posts formed from spin-on glass, on a substrate. In alternate embodiments, the posts may be formed after certain layers of the modulator element have been deposited on the substrate. An interferometric modulator element includes at least two spin-on glass support posts located on the substrate. In alternate embodiments, the support posts may be located over certain layers of the modulator element, rather than on the substrate. A method of making an interferometric modulator element includes forming a rigid cap over a support post. An interferometric modulator element includes support posts having rigid cap members.

Claims

1. A method of forming an interferometric display element, comprising:

providing a substrate;

depositing a layer of support post material over the substrate;

patterning the layer of support post material to form at least two support posts;

forming an electrode layer over the substrate, wherein the forming of the electrode layer is done after the forming of the at least two support posts;

forming at least a first sacrificial layer over the electrode layer; and

forming a mechanical layer over the sacrificial layer, wherein the mechanical layer covers a portion of each of the at least two support posts.

2. The method of claim 1, wherein the support post material comprises spin-on glass.

3. The method of claim 1, wherein the support post material comprises an insulator.

4. The method of claim 3, wherein the insulator comprises silicon oxide.

5. The method of claim 1, wherein the support post material comprises a metal.

6. The method of claim 1, wherein the mechanical layer comprises a reflective surface.

7. The method of claim 1, additionally comprising:

forming a mirror layer over the electrode layer; and

patterning the mirror layer to form a mirror.

8. The method of claim 7, additionally comprising:

depositing a second layer of sacrificial material over the mirror; and

patterning the second layer of sacrificial material, thereby forming at least one hole in said second layer of sacrificial material, said hole being located over the mirror element.

9. The method of claim 1, wherein forming a mechanical layer over the sacrificial layer comprises:

forming a planarization layer over the sacrificial layer;

etching back the planarization layer to provide a substantially planar surface; and

forming a mechanical layer over the planarization layer.

10. The method of claim 1, additionally comprising:

patterning the mechanical layer, thereby exposing at least a portion of an underlying layer; and

etching the sacrificial layer to remove said sacrificial layer.

18. The apparatus of claim 8, wherein the support posts comprise a planarization material.

11. An apparatus, said apparatus comprising a plurality of interferometric modulator elements, said interferometric modulator elements comprising:

a substrate;

an electrode layer located over the substrate;

at least two support posts located on the substrate; and

a mechanical layer located over the electrode layer, said mechanical layer being supported by the at least two support posts.

12. The apparatus of claim 11, wherein the mechanical layer comprises a reflective surface facing the substrate.

13. The apparatus of claim 11, additionally comprising a mirror, wherein said mirror is located over the electrode layer, and wherein said mirror is connected to the mechanical layer.

14. The apparatus of claim 11, wherein the support posts comprise spin-on glass.

15. The apparatus of claim 14, wherein the support posts are in direct contact with the substrate.

16. The apparatus of claim 11, wherein the support posts comprise metal.

17. The apparatus of claim 11, wherein the support posts comprise an insulator.

19. The apparatus of claim 11, further comprising:

a display, wherein the display comprises the plurality of interferometric modulator elements;

a processor in electrical communication with said display, said processor being configured to process image data; and

a memory device in electrical communication with said processor.

20. The display system as recited in claim 19, further comprising:

a first controller configured to send at least one signal to said display; and

a second controller configured to send at least a portion of said image data to said first controller.

21. The display system as recited in claim 19, further comprising:

an image source module configured to send said image data to said processor.

22. The display system as recited in claim 21, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

23. The display system as recited in claim 19, further comprising:

an input device configured to receive input data and to communicate said input data to said processor.

24. A method of forming an interferometric display element, comprising:

providing a substrate;

forming an electrode layer over the substrate;

forming at least two support posts over the substrate, wherein the forming of the at least two support posts is done after the forming of the electrode layer;

forming at least a first sacrificial layer over the electrode layer; and

forming a mechanical layer over the sacrificial layer, wherein the mechanical layer covers a portion of each of the at least two support posts.

25. The method of claim 24, wherein forming at least two support posts over the substrate comprises:

depositing a layer of support post material over the substrate; and

patterning the layer of support post material to form the at least two support posts.

26. The method of claim 25, wherein the layer of support post material is deposited over the electrode layer.

27. The method of claim 26, wherein the layer of support post material comprises metal.

28. The method of claim 26, wherein the layer of support post material comprises an insulator.

29. The method of claim 26, wherein the layer of support post material comprises a planarization material.

30. A display, said display comprising a plurality of interferometric display elements, said interferometric display elements comprising:

a substrate;

an electrode layer located over the substrate;

at least two support posts located on the electrode layer, wherein said posts comprise planarization material; and

a mechanical layer located over the electrode layer, said mechanical layer being supported by the at least two support posts.

31. The display of claim 30, wherein the mechanical layer comprises a reflective surface facing the substrate.

32. The display of claim 30, additionally comprising a mirror, wherein said mirror is located over the electrode layer, and wherein said mirror is connected to the mechanical layer.

33. A display containing a plurality of interferometric modulators, wherein said interferometric modulators are formed by a method comprising:

providing a substrate;

depositing a layer of support post material over the substrate;

patterning the layer of support post material to form at least two support posts;

forming an electrode layer over the substrate, wherein the forming of the electrode layer is done after the forming of the at least two support posts;

forming at least a first sacrificial layer over the electrode layer; and

forming a mechanical layer over the sacrificial layer, wherein the mechanical layer covers a portion of each of the at least two support posts.

34. A method of making an interferometric display element, comprising:

providing a substrate;

forming support posts over the substrate;

forming an electrode layer over the substrate;

depositing a sacrificial layer over the electrode layer;

forming a substantially planar surface over the sacrificial layer;

forming a mechanical layer over the substantially planar surface;

forming an insulator layer over at least part of the mechanical layer; and

forming a substantially rigid support layer over the insulation layer.

35. The method of claim 34, wherein the support posts comprise spin-on-glass.

36. The method of claim 35, wherein the electrode layer is formed after the support posts have been formed.

37. The method of claim 34, wherein the support posts are formed after the electrode layer is formed.

38. The method of claim 37, wherein the support posts comprise a conductive material.

39. The method of claim 37, wherein the support posts comprise an insulator.

40. The method of claim 37, wherein forming an electrode layer over the substrate comprises depositing a layer of ITO over the substrate and depositing a partially reflective layer over the ITO, and wherein the support posts are formed over the partially reflective layer.

41. The method of claim 40, wherein the partially reflective layer comprises chrome or a chrome alloy.

42. The method of claim 34, wherein forming a substantially planar surface over the sacrificial layer comprises:

depositing a layer of planarization material over the layer of sacrificial material; and

etching back the planarization material to form a substantially planar surface.

43. The method of claim 34, wherein forming a mechanical layer over the substantially planar surface comprises:

depositing a mechanical layer over the substantially planar surface; and

patterning the mechanical layer.

44. The method of claim 43, wherein at least a portion of the mechanical layer is deposited over the support posts, and wherein patterning the mechanical layer comprises selectively removing the portions of the mechanical layer over the support posts.

45. The method of claim 34, wherein forming an insulation layer over the mechanical layer comprises:

depositing a layer of insulation material over at least a portion of the mechanical layer and the support posts; and

patterning the layer of insulation material, wherein at least a contiguous section of the layer of insulation material remains, said contiguous section being located over at least part of a support post and at least part of the mechanical layer.

46. The method of claim 45, additionally comprising etching the insulation layer to expose at least a portion of the underlying support posts.

47. The method of claim 46, wherein the exposed portion of the support post comprises a conductive material.

48. The method of claim 47, wherein forming a substantially rigid support layer comprises depositing a layer of conductive material.

49. The method of claim 34, wherein forming a substantially rigid support layer over the insulation layer comprises:

depositing a layer of support material over the insulation layer; and

patterning the layer of support material, wherein at least a contiguous section of the layer of support material remains, said contiguous section overlying at least a part of a support post and at least part of the mechanical layer.

50. An apparatus, plurality of interferometric modulator elements, said interferometric modulator elements comprising:

a substrate;

an electrode layer located over the substrate;

a plurality of support posts located over the substrate;

a rigid cap member located over each of at least some of the plurality of support posts, said rigid cap member comprising an insulator layer; and

a mechanical layer located over the partially reflective electrode layer, wherein said mechanical layer is attached to the insulator layers of at least two rigid cap members.

51. The apparatus of claim 50, wherein the mechanical layer comprises a reflective surface located on the same side of the mechanical layer as the substrate.

52. The apparatus of claim 50, additionally comprising a mirror layer, wherein said mirror layer located over the electrode layer, and wherein said mirror layer is connected to the mechanical layer.

53. The apparatus of claim 52, wherein the insulator layer is located on the side of the rigid cap member facing the substrate.

54. The apparatus of claim 52, wherein the insulator layer is located on the side of the rigid cap member opposite the substrate.

55. The apparatus of claim 50, wherein the electrode layer does not extend between the support post and the substrate.

56. The apparatus of claim 55, wherein the support posts comprise spin-on glass.

57. The apparatus of claim 50, wherein the support posts comprise hardened planarization material.

58. The apparatus of claim 50, wherein the support posts are located over a portion of the electrode layer.

59. The apparatus of claim 58, wherein the support posts comprise an insulator.

60. The apparatus of claim 59, wherein the support posts comprise silicon oxide.

61. The apparatus of claim 58, wherein the support posts comprise a conductive material.

62. The apparatus of claim 50, further comprising:

a display, wherein the display comprises the plurality of interferometric modulator elements;

a processor that is in electrical communication with said display, said processor being configured to process image data; and

a memory device in electrical communication with said processor.

63. The display system as recited in claim 62, further comprising:

a first controller configured to send at least one signal to said display; and

a second controller configured to send at least a portion of said image data to said first controller.

64. The display system as recited in claim 62, further comprising:

an image source module configured to send said image data to said processor.

65. The display system as recited in claim 64, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

66. The display system as recited in claim 62, further comprising:

an input device configured to receive input data and to communicate said input data to said processor.

67. A method of making a display element, comprising:

depositing an electrode layer on a substrate;

patterning the electrode layer;

depositing a layer of sacrificial material over the electrode layer;

patterning the layer of sacrificial material to form apertures;

forming support posts in the apertures;

forming a flexible layer over the layer of sacrificial material;

depositing an insulator layer over the flexible layer;

depositing a rigid support layer over the insulator layer; and

removing the sacrificial material;

thereby permitting movement of the flexible layer relative to the substrate.

68. The method of claim 67, wherein forming support posts in the apertures comprises:

depositing a layer of planarization material in the aperture; and

exposing the planarization material to a temperature sufficiently high to harden the planarization material.

69. The method of claim 68, wherein forming a flexible layer over the layer of sacrificial material comprises:

depositing a flexible layer over the layer of sacrificial material; and

patterning the flexible layer.

70. The method of claim 67, additionally comprising patterning the insulator layer and the rigid support layer, forming a cap member overlying the support post.

71. A method of making a display element, comprising:

depositing an electrode layer on a substrate;

patterning the electrode layer;

depositing a layer of sacrificial material over the electrode layer;

patterning the layer of sacrificial material to form apertures;

depositing a layer of non-planarizing support post material on the sacrificial material;

patterning the non-planarizing support post material so as to remove support post material located away from the apertures, thereby forming support posts;

forming a flexible layer over the support posts; and

removing the sacrificial material;

thereby permitting movement of the flexible layer relative to the substrate.

72. The method of claim 71, additionally comprising:

depositing a layer of insulator material over at least the support posts; and

patterning the insulator material so as to remove insulator material located away from the support posts.

73. The method of claim 72, wherein forming a flexible layer over at least the support posts comprises:

depositing a flexible layer over at least the insulator layer; and

patterning the flexible layer.

74. A display containing a plurality of interferometric modulators, wherein said interferometric modulators are formed by a method comprising:

providing a substrate;

forming support posts over the substrate;

forming an electrode layer over the substrate;

depositing a sacrificial layer over the electrode layer;

forming a substantially planar surface over the sacrificial layer;

forming a mechanical layer over the substantially planar surface;

forming an insulator layer over at least part of the mechanical layer; and

forming a substantially rigid support layer over the insulation layer.