DISPLAY APPARATUS AND METHODS FOR MANUFACTURE THEREOF

• US 20080158635A1
• Filed: 03/10/2008
• Published: 07/03/2008
• Est. Priority Date: 02/23/2005
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Barton, Roger, Hagood, Nesbitt W., Gandhi, Jignesh, Payne, Richard S., Fijol, John J., Steyn, Jasper Lodewyk, Brosnihan, Timothy J.
• Application Number:
  US12/045,518
• Publication Number:
  US 20080158635A1
• Time in Patent Office: Days
• US Class Current: 359/230
• CPC Class Codes: G02B 26/00 Optical devices or arrangements for the control of light using movable or deformable optical elements control of light by modification of the optical properties of the media of the elements involved therein G02F1/00
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38

Abstract

Display devices incorporating shutter-based light modulators are disclosed along with methods of manufacturing such devices. The methods are compatible with thin-film manufacturing processes known in the art and result in displays having lower power-consumption.

Claims

1. A MEMS-based shutter assembly for a spatial light modulator comprising:

a substrate;

a shutter supported over the substrate, wherein the shutter comprises;

a first portion, which, in a first shutter position, is oriented substantially horizontally with respect to the substrate; and

at least one second portion, which in the first shutter position, is at least partially transverse to first portion; and

an actuator for moving the shutter to selectively modulate light.

2. The MEMS-based shutter assembly of claim 1, wherein the at least second portion provides the shutter with an effective thickness with respect to bending normal to the first shutter portion that is greater than the thickness of the first portion.

3. The MEMS-based shutter assembly of claim 1, wherein a front surface of the substrate defines a plane, and the at least second portion provides the shutter with an effective thickness with respect to bending out of the defined plane that is greater than the thickness of the first portion.

4. The MEMS-based shutter assembly of claim 1, wherein the at least one second portion extends along substantial portions of the periphery of the shutter.

5. The MEMS-based shutter assembly of claim 1, wherein the at least one second portion comprises a sidewall structure.

6. The MEMS-based shutter assembly of claim 5, wherein the sidewall structure comprises a first materials and the first portion comprises a second, different material.

7. The MEMS-based shutter assembly of claim 5, wherein the sidewall structure comprises a first materials and the first portion comprises the same first material.

8. The MEMS-based shutter assembly of claim 5, wherein the first and second portions of the shutter provide the shutter a three-dimensional aspect.

9. The MEMS-based shutter assembly of claim 8, wherein the three-dimensional aspect comprises a corrugation.

10. A method of manufacturing a display device comprising:

depositing a light blocking layer on a substantially transparent glass substrate;

forming a plurality of light transmissive regions in the light blocking layer;

depositing an insulating layer directly on top of the light blocking layer;

forming a plurality of via holes in the insulating layer;

forming a plurality of thin-film components on the insulating layer

such that the plurality of thin-film components electrically connect to the light blocking layer at the plurality of via holes; and

forming a plurality of light-modulating shutter assemblies above, and in electrical communication with, the plurality of thin film components such that the thin-film components form a control matrix for controlling the light modulation of the plurality of light-modulating shutter assemblies.

11. The method of claim 10, wherein the light blocking layer comprises a light-reflecting material.

12. The method of claim 10, wherein the light blocking layer comprises a light-absorbing material.

13. The method of claim 10, wherein the light blocking layer comprises a light-absorbing material and a light-reflecting material.

14. The method of claim 10, wherein the light blocking layer is deposited directly on top of the substantially transparent substrate.

15. The method of claim 10, comprising depositing at least one layer of material between the substantially transparent substrate and the light blocking layer.

16. The method of claim 10, wherein the light transmissive regions comprise apertures.

17. The method of claim 10, wherein patterning the light blocking layer comprises patterning electrical interconnects into the light blocking layer.

18. The method of claim 10, wherein the shutter assemblies include shutters for obstructing light transmissive regions formed in the light blocking layer.

19. A method of manufacturing a display device comprising:

depositing an light blocking layer comprising a light absorbing material on a substantially transparent substrate;

forming a plurality of light transmissive regions in the light blocking layer;

depositing an insulating layer on top of the light blocking layer; and

forming a plurality of light-modulating shutter assemblies on top of the insulating layer.

20. The method of claim 19, wherein the light absorbing material comprises one of MoCr, MoW, MoTi, MoTa, TiW, and TiCr.

21. The method of claim 19, wherein the light absorbing material comprises an amorphous semiconductor.

22. The method of claim 19, wherein the light absorbing material comprises a polycrystalline semiconductor.

23. The method of claim 19, wherein the light absorbing material comprises an alloy of at least two semiconductors.

24. The method of claim 19, wherein the light absorbing material comprises one Ni and Cr, and depositing the light blocking layer comprises depositing the light absorbing material with a roughened surface.

25. The method of claim 19, wherein the light absorbing material comprises a metal oxide.

26. The method of claim 19, wherein the light absorbing material comprises a metal nitride.

27. The method of claim 19, wherein depositing the light blocking layer comprises depositing the light-absorbing material such that it forms an oxide lattice having a deficiency of oxygen.

28. The method of claim 19, wherein depositing the light blocking layer comprises depositing the light-absorbing material comprises depositing a plurality of thin films.

29. The method of claim 19, wherein depositing the light blocking layer comprises depositing the light-absorbing material in a non-stoichimetric fashion.

30. The method of claim 19, wherein depositing the light blocking layer comprises depositing the light-absorbing material to form a rough surface.

31. The method of claim 19, wherein the light absorbing material is at least 500 nm thick.

32. The method of claim 19, wherein the light transmissive regions comprise apertures.

33. The method of claim 19, wherein forming the plurality of light transmissive regions comprises etching apertures into the light blocking layer but not the insulating layer.

34. The method of claim 19, wherein forming the plurality of light transmissive regions comprises etching apertures into the light blocking layer and the insulating layer.

35. The method of claim 19, wherein the light blocking layer comprises a reflective material, and the light absorbing material absorbs light impinging on the light blocking layer from a first direction and reflects light impinging on the light blocking layer from an opposite direction.

36. The method of claim 19, wherein the shutter assemblies comprise light blocking regions that correspond to respective light transmissive regions formed in the light blocking layer.

37. The method of claim 19, wherein the light absorbing material absorbs at least about 30% of incident light.

38. The method of claim 19, wherein the light blocking layer is deposited directly on top of the substantially transparent substrate.

39. The method of claim 19, comprising depositing at least one layer of material between the substantially transparent substrate and the light blocking layer.

40. The method of claim 19, wherein patterning the light blocking layer comprises patterning electrical interconnects into the light blocking layer.

41. method of manufacturing a display device comprising:

depositing a light blocking metal layer on a substantially transparent substrate;

etching the metal layer to form electrical components of a control matrix and a plurality of light transmissive regions in the metal layer; and

forming a plurality of light-modulating shutter assemblies, including shutters, on top of the light blocking metal layer, such that the shutters and the light blocking metal layer are maintained at the same electric potential.

42. The method of claim 41, comprising depositing an insulating layer on top of the metal layer, and wherein the plurality of light modulators are formed on top of the insulating layer.

43. The method of claim 41, wherein the electrical components of the control matrix comprise components of a plurality of switches.

44. The method of claim 41, wherein the electrical components of the control matrix comprise electrical interconnects.

45. The method of claim 41, wherein the thickness of the metal layer is greater than 300 Angstroms.

46. The method of claim 41, wherein the metal of the metal layer is comprised of materials the absorb more than 30% of incident light.

47. The method of claim 41, wherein the metal of the metal layer is highly reflective.

48. The method of claim 41, wherein the metal of the metal layer is comprised of one of Al, Ag, or Au.

49. The method of claim 41, wherein the shutter assemblies include shutters for obstructing light transmissive regions formed in the light blocking metal layer.

50. The method of claim 41, wherein the light transmissive regions comprise apertures.

51. The method of claim 41, wherein the light blocking layer is deposited directly on top of the substantially transparent substrate.

52. The method of claim 41, comprising depositing at least one layer of material between the substantially transparent substrate and the light blocking layer.

53. The method of claim 41, wherein the plurality of shutter assemblies are configured for imparting motion on corresponding shutters substantially in a plane which is parallel to the light blocking metal layer.

54. A microelectromechanical display comprising:

a multilayer control matrix, including conductive components in at least first and second layers of the control matrix;

a microelectromechanical light modulator; and

a conductive oxide electrical connection that connects at least one electrically conductive component in the first layer of the control matrix to an electrically conductive component in the second layer of the control matrix or to the microelectromechanical light modulator.

55. The display of claim 54, wherein the conductive oxide connection comprises a via hole filled with conductive oxide that electrically connects the at least one electrically conductive component in the first layer to the electrically conductive component of the second layer of the control matrix.

56. The display of claim 54, wherein the conductive oxide connection comprises a via hole filled with conductive oxide that electrically connects the at least one electrically conductive component in the first layer of the control matrix to the microelectromechanical light modular.

57. The display of claim 54, wherein the conductive oxide connection comprises a strap connection between the at least one electrically conductive component in the first layer to the electrically conductive component of the second layer of the control matrix.

58. The display of claim 54, wherein the conductive oxide connection comprises a bond pad connection between the control matrix and drive circuitry.

59. The display of claim 54, wherein the conductive oxide connection provides chemical protection for at least one electrical component in the control matrix.

60. The display of claim 54, wherein the conductive oxide comprises indium-tin-oxide.

61. A microelectromechanical device comprising:

a first component defining a plane; and

a beam including at least one amorphous silicon layer suspended over the first component, wherein a dimension of the beam normal to the defined plane is substantially greater than at least one dimension of the beam within the defined plane.

62. The device of claim 61, wherein the beam comprises at least one additional layer composed of a material other than amorphous silicon.

63. The device of claim 61, wherein the beam is a sidewall beam.

64. The device of claim 61, further comprising a second component that is movable in relation to the first component, wherein the second component is suspended above the first component at least in part by the beam.

65. The device of claim 61, wherein the beam comprises at least one surface normal to the defined plane, and wherein the beam exhibits residual stress normal to the surface.

66. The device of claim 61, wherein the device is part of a display assembly.

67. The device of claim 61, wherein the second component is a mechanical shutter.

68. The device of claim 61, comprising an actuator which includes the beam.

69. The device of claim 68, wherein the beam is part of a shutter mechanism.

70. The device of claim 61, wherein the amorphous silicon layer is conductive.

71. The device of claim 61, wherein the amorphous silicon layer is non-conductive.

72. The device of claim 61, wherein the beam is electrically connected to the first component by an indium-tin-oxide interconnect.

73. The device of claim 62 wherein the at least one additional layer comprises a elastic material.

74. The device of claim 62, wherein the at least one additional layer comprises a conductive material.

75. The device of claim 62, wherein the at least one additional layer comprises an opaque material.

76. The device of claim 62, wherein the at least one additional layer comprises a dielectric material.

77. The device or claim 62, wherein the at least one additional layer comprises an optically absorptive material.

78. The device of claim 62, wherein the at least one additional layer is an anti-stiction material.

79. The device of claim 61, wherein the dimension of the beam within the defined plane is less than 2 microns.

80. The device of claim 61, wherein the dimension of the beam normal to the defined plane is at least 1.4 times the dimension of the beam within the defined plane.

81. A MEMS-based spatial light modulator comprising:

a substrate; and

a moveable element supported over the substrate, wherein the moveable portion comprises a compliant beam that exhibits an unbalanced state of stress such that the beam adopts a desired state of curvature.

82. The MEMS-based spatial light modulator of claim 81, wherein the unbalanced state of stress originates from a laminated construction.

83. The MEMS-based spatial light modulator of claim 81, wherein the lamination construction comprises a layer of amorphous silicon and a metal layer or an insulating layer.