Mirror and mirror layer for optical modulator and method

• US 20060077518A1
• Filed: 07/01/2005
• Published: 04/13/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Chui, Clarence, Sampsell, Jeffrey B.
• Granted Patent: US 7,417,783 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• 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
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

Described herein are systems, devices, and methods relating to packaging electronic devices, for example, microelectromechanical systems (MEMS) devices, including optical modulators such as interferometric optical modulators. The interferometric modulator disclosed herein comprises a movable mirror. Some embodiments of the disclosed movable mirror exhibit a combination of improved properties compared to known mirrors, including reduced moving mass, improved mechanical properties, and reduced etch times.

Claims

1. A microelectromechanical systems mirror comprising a mirror body, wherein

a surface of the mirror body comprises a reflective surface, and

the mirror body comprises at least one cavity.

2. The microelectromechanical systems mirror of claim 1, wherein the mirror body further comprises a reflective layer, and wherein the reflective surface comprises a surface of the reflective layer.

3. The microelectromechanical systems mirror of claim 1, wherein the mirror body comprises aluminum or aluminum alloy.

4. The microelectromechanical systems mirror of claim 1, wherein the reflective surface is an aluminum or aluminum alloy surface.

5. The microelectromechanical systems mirror of claim 1, wherein a cavity is at least in part defined by a layer of a body material substantially parallel to the reflective surface.

6. The microelectromechanical systems mirror of claim 5, comprising a plurality of cavities at least in part defined by a plurality of layers of a body material, wherein each layer of body material is substantially parallel to the reflective surface.

7. The microelectromechanical systems mirror of claim 6, further comprising a spacer disposed between and secured to adjacent layers of the body material.

8. The microelectromechanical systems mirror of claim 6, further comprising a plurality of pins extending through and secured to the layers of the body material.

9. The microelectromechanical systems mirror of claim 1, wherein the mirror body is porous.

10. The microelectromechanical systems mirror of claim 1, wherein the at least one cavity is at least in part defined by one or more structures comprising elements that are substantially perpendicular to the reflective surface.

11. The microelectromechanical systems mirror of claim 10, comprising a plurality of cavities defined at least in part by one or more structures comprising elements that are substantially perpendicular to the reflective surface.

12. The microelectromechanical systems mirror of claim 11, wherein the structures comprise a plurality of pins.

13. The microelectromechanical systems mirror of claim 11, wherein at least some of the cavities form a substantially square grid.

14. The microelectromechanical systems mirror of claim 11, wherein at least some of the cavities form a substantially hexagonal grid.

15. The microelectromechanical systems mirror of claim 11, further comprising a connector contact area on the mirror body.

16. A microelectromechanical systems mirror comprising a mirror body, wherein

a surface of the mirror body comprises a reflective surface,

the mirror body comprises a body material and a sacrificial material, and

the sacrificial material is preferentially etchable over the body material.

17. The microelectromechanical systems mirror of claim 16, wherein the body material comprises aluminum or aluminum alloy, and the sacrificial material comprises molybdenum.

18. The microelectromechanical systems mirror of claim 16, wherein the body material and sacrificial material form alternating layers substantially parallel to the reflective surface.

19. The microelectromechanical systems mirror of claim 16, wherein the body material and sacrificial material form a composite, wherein the composite comprises the body material at least at the percolation threshold.

20. The microelectromechanical systems mirror of claim 19, wherein the composite comprises the sacrificial material at least at the percolation threshold.

21. A method for fabricating a microelectromechanical systems mirror comprising a mirror body, wherein a surface of the mirror body comprises a reflective surface, the method comprising:

depositing a mirror body comprising a reflective surface, wherein

the mirror body comprises a body material and a sacrificial material, and

the sacrificial material is preferentially etchable over the body material.

22. The method of claim 21, wherein the reflective surface is a surface of a reflective layer.

23. The method of claim 21, wherein the body material comprises aluminum or aluminum alloy, and the sacrificial material comprise molybdenum.

24. The method of claim 21, wherein the body material and sacrificial material form alternating layers substantially parallel to the reflective surface.

25. The method of claim 21, wherein the body material and sacrificial material form a composite, wherein the composite comprises the body material at least a percolation threshold.

26. The method of claim 25, wherein the composite comprises the sacrificial material at least a percolation threshold.

27. The method of claim 21, further comprising depositing an etch stop between the layer comprising a reflective surface and the body.

28. The method of claim 21, further comprising forming an opening in the mirror body.

29. The method of claim 21, further comprising etching at least a portion of the sacrificial material from the body.

30. The method of claim 29, wherein the etching is performed using xenon difluoride.

31. The method of claim 29, wherein the etching of the at least a portion of the sacrificial material from the body is performed simultaneously with the etching of another sacrificial material in a device comprising the microelectromechanical systems mirror.

32. A method for fabricating a microelectromechanical systems mirror comprising a mirror body, wherein a surface of the mirror body comprises a reflective surface disposed on a surface of the mirror body, and wherein the mirror body comprises at least one cavity, the method comprising:

depositing a mirror body comprising the reflective surface, and

etching a cavity in the mirror body.

33. The method of claim 32, wherein the mirror body is aluminum or aluminum alloy.

34. The method of claim 32, wherein the at least one cavity is at least in part defined by one or more structures comprising elements that are substantially perpendicular to the reflective surface.

35. The method of claim 34, wherein the at least one cavity is formed by etching a sacrificial material from mirror body.

36. The method of claim 34, wherein the at least one cavity is formed by etching a body material from mirror body.

37. A microelectromechanical systems mirror comprising a mirror body and a reflective surface disposed on a face of the body, wherein the mirror body comprises a means for forming a cavity therein.

38. The microelectromechanical systems mirror of claim 37, wherein the mirror body is aluminum or aluminum alloy.

39. A microelectromechanical systems mirror comprising a mirror body, wherein a surface of the mirror body comprises a reflective surface, the microelectromechanical systems mirror manufactured by a method comprising:

forming the mirror body comprising the reflective surface, wherein

the mirror body comprises a body material and a sacrificial material, and

the sacrificial material is preferentially etchable over the body material; and

etching at least some of the sacrificial material from the mirror body.

40. An interferometric modulator comprising a first mirror and a second mirror, wherein the second mirror comprises a mirror body, wherein a surface of the mirror body compises a reflective surface disposed on a face of the body, wherein the body comprises at least one cavity.

41. The interferometric modulator of claim 40, further comprising a deformable layer and an annular connector, wherein

the second mirror is disposed between the first mirror and the deformable layer,

the reflective surface is proximal to the first mirror, and

the annular connector extends between the second mirror and the deformable layer.

42. A display system comprising:

a display comprising an array of the interferometric modulator of claim 40;

a processor in electrical communication with the display, wherein the processor configured to process image data; and

a memory device in electrical communication with the processor.

43. The display system of claim 42, 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.

44. The display system of claim 42, further comprising an image source module configured to send said image data to said processor.

45. The display system of claim 44, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

46. The display system as recited in claim 42, further comprising an input device configured to receive input data and to communicate the input data to the processor.

47. A method for fabricating a microelectromechanical systems mirror comprising a mirror body, wherein a surface of the mirror body comprises a reflective surface, the method comprising:

forming a mirror body comprising a reflective surface, wherein

the mirror body comprises a body material and a sacrificial material, and

the sacrificial material is preferentially etchable over the body material; and

treating at least a portion of the sacrificial material to provide a treated material, wherein the sacrificial material is selectively etchable over the treated material and the body material.

48. The method of claim 47, wherein

the body material and sacrificial material form alternating layers that are substantially parallel to the reflective surface, and

the treated material is formed around the periphery of the mirror body.

49. The method of claim 47, wherein the treated material is porous.

50. The method of claim 47, further comprising forming an opening in the mirror body, wherein the opening contacts the sacrificial material.

51. The method of claim 47, further comprising selectively etching the sacrificial material.