MICROELECTROMECHANICAL SYSTEM HAVING A DIELECTRIC MOVABLE MEMBRANE AND A MIRROR

• US 20080278787A1
• Filed: 05/09/2007
• Published: 11/13/2008
• Est. Priority Date: 05/09/2007
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm, Inc.
• Inventors: Sasagawa, Teruo
• Granted Patent: US 7,643,202 B2
• Time in Patent Office: Days
• US Class Current: 359/224
• 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 microelectromechanical (MEMS) device includes at least one electrode, a first reflective layer, and a movable functional element. The movable functional element includes a flexible dielectric layer and a reflective element. The flexible dielectric layer flexes in response to voltages applied to the at least one electrode to move the functional element in a direction generally perpendicular to the first reflective layer. The reflective element has a first portion mechanically coupled to the flexible dielectric layer and a second portion spaced from the flexible dielectric layer and defining a gap therebetween.

Claims

1. A microelectromechanical (MEMS) device comprising:

at least one electrode;

a first reflective layer; and

a movable functional element comprising;

a flexible dielectric layer that flexes in response to voltages applied to the at least one electrode to move the functional element in a direction generally perpendicular to the first reflective layer; and

a reflective element having a first portion mechanically coupled to the flexible dielectric layer and a second portion spaced from the flexible dielectric layer and defining a gap therebetween.

2. The MEMS device of claim 1, wherein the flexible dielectric layer comprises SiO₂.

3. The MEMS device of claim 1, wherein the reflective element comprises aluminum.

4. The MEMS device of claim 1, wherein the reflective element comprises:

a second reflective layer;

an electrically conductive layer in electrical communication with the second reflective layer via a communication path; and

a second dielectric layer between the second reflective layer and the electrically conductive layer.

5. The MEMS device of claim 4, wherein the communication path is disposed over an edge of the reflective element.

6. The MEMS device of claim 4, wherein the second dielectric layer includes a notch in an edge of the second dielectric layer, at least a portion of the communication path being within the notch.

7. The MEMS device of claim 4, wherein the second dielectric layer includes a first notch in a first edge of the second dielectric layer and a second notch in a second edge of the second dielectric layer, at least a portion of the communication path being within the first and second notches.

8. The MEMS device of claim 4, wherein the second dielectric layer includes at least one edge and a plurality of notches in the at least one edge, at least a portion of the communication path being within the plurality of notches.

9. The MEMS device of claim 4, wherein the communication path extends through the reflective element.

10. The MEMS device of claim 1, further comprising an electrically conductive layer over a side of the flexible dielectric layer opposite the reflective element, the conductive layer in electrical communication with the reflective element.

11. The MEMS device of claim 1, further comprising:

a display;

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

a memory device that is configured to communicate with said processor.

12. The MEMS device of claim 11, further comprising a driver circuit configured to send at least one signal to the display.

13. The MEMS device of claim 12, further comprising a controller configured to send at least a portion of the image data to the driver circuit.

14. The MEMS device of claim 11, further comprising an image source module configured to send said image data to said processor.

15. The MEMS device of claim 14, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

16. The MEMS device of claim 11, further comprising an input device configured to receive input data and to communicate said input data to said processor.

17. A microelectromechanical (MEMS) device comprising:

first means for reflecting;

means for moving a portion of the device, the moving means comprising;

second means for reflecting; and

means for supporting the second reflecting means, a first portion of the supporting means mechanically coupled to the second reflecting means and a second portion of the supporting means spaced from the second reflecting means and defining a gap therebetween, the supporting means having a flexible dielectric portion; and

means for actuating the moving means to move the second reflecting means in a direction generally perpendicular to the first reflecting means.

18. The MEMS device of claim 17, wherein the first reflecting means comprises a first reflective layer.

19. The MEMS device of claim 17, wherein the moving means comprises a movable functional element.

20. The MEMS device of claim 17, wherein the second reflecting means comprises a second reflective layer.

21. The MEMS device of claim 17, wherein the supporting means comprises a flexible dielectric layer.

22. The MEMS device of claim 17, wherein the actuating means comprises at least one electrode.

23. A method of manufacturing a microelectromechanical (MEMS) device, the method comprising:

providing a first reflective layer;

forming a first sacrificial layer over the first reflective layer;

forming a functional element over the first sacrificial layer, wherein forming the functional element comprises;

forming a reflective element over the first sacrificial layer, the reflective element having a reflective surface substantially parallel to the first reflective layer;

forming a second sacrificial layer over the reflective element;

forming an aperture through the second sacrificial layer and over the reflective element; and

forming a flexible dielectric layer over the second sacrificial layer, the flexible dielectric layer mechanically coupled to the reflective element through the aperture; and

removing the first and second sacrificial layers such that the functional element is movable in a direction generally perpendicular to the first reflective layer.

24. The method of claim 23, wherein forming the reflective element comprises depositing a metal layer over the first sacrificial layer.

25. The method of claim 23, wherein forming the reflective element comprises:

forming a second reflective layer over the first sacrificial layer;

forming a second dielectric layer over the second reflective layer;

forming an electrically conductive layer over the second dielectric layer; and

forming a communication path between the conductive layer and the second reflective layer.

26. The method of claim 25, wherein forming the communication path comprises depositing at least a portion of the conductive layer over an edge of the second dielectric layer such that the conductive layer is in electrical communication with the second reflective layer.

27. The method of claim 25, wherein forming the communication path comprises forming a notch in an edge of the second dielectric layer and depositing at least a portion of the conductive layer within the notch.

28. The method of claim 25, wherein forming the communication path comprises forming a first notch in a first edge of the second dielectric layer and a second notch in a second edge of the second dielectric layer and depositing at least a portion of the conductive layer within the first and second notches.

29. The method of claim 23, further comprising forming a conductive layer over a side of the flexible dielectric layer opposite from the reflective element.

30. A microelectromechanical (MEMS) device fabricated by the method of claim 23.

31. A microelectromechanical (MEMS) device comprising:

at least one electrode;

a first reflective layer; and

a movable functional element comprising;

a flexible layer that flexes in response to voltages applied to the at least one electrode to move the functional element in a direction generally perpendicular to the first reflective layer; and

a reflective element having a first portion mechanically coupled to the flexible layer and a second portion spaced from the flexible layer and defining a gap therebetween, the reflective element comprising;

a second reflective layer;

an electrically conductive layer in electrical communication with the second reflective layer via a communication path; and

a dielectric layer between the second reflective layer and the electrically conductive layer.

32. The MEMS device of claim 31, wherein the second reflective layer comprises aluminum.

33. The MEMS device of claim 31, wherein the electrically conductive layer comprises aluminum.

34. The MEMS device of claim 31, wherein the dielectric layer comprises SiO₂.

35. The MEMS device of claim 31, wherein the flexible layer comprises nickel.

36. The MEMS device of claim 31, wherein the flexible layer comprises a flexible dielectric layer.

37. A microelectromechanical (MEMS) device comprising:

first means for reflecting;

means for moving a portion of the device, the moving means comprising;

second means for reflecting, the second reflecting means including a dielectric portion; and

means for supporting the second reflecting means, a first portion of the supporting means mechanically coupled to the second reflecting means and a second portion of the supporting means spaced from the second reflecting means and defining a gap therebetween; and

means for actuating the moving means to move the second reflecting means in a direction generally perpendicular to the first reflecting means.

38. The MEMS device of claim 37, wherein the first reflecting means comprises a first reflective layer.

39. The MEMS device of claim 37, wherein the moving means comprises a movable functional element.

40. The MEMS device of claim 37, wherein the second reflecting means comprises a reflective element comprising:

a second reflective layer;

an electrically conductive layer in electrical communication with the second reflective layer via a communication path; and

a dielectric layer between the second reflective layer and the electrically conductive layer.

41. The MEMS device of claim 37, wherein the supporting means comprises a flexible dielectric layer.

42. The MEMS device of claim 37, wherein the supporting means comprises a layer of nickel.

43. The MEMS device of claim 37, wherein the actuating means comprises at least one electrode.