MICROELECTROMECHANICAL SYSTEM HAVING A DIELECTRIC MOVABLE MEMBRANE AND A MIRROR

• US 20080278788A1
• 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 7,715,085 B2
• Time in Patent Office: Days
• US Class Current: 359/224
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 3/0072 For controlling internal stress or strain in moving or flexible elements, e.g. stress compensating layers
• 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 reflective element. The movable reflective element includes a flexible dielectric layer and a second reflective layer mechanically coupled to the flexible dielectric layer. The flexible dielectric layer flexes in response to voltages applied to the at least one electrode to move the reflective element in a direction generally perpendicular to the first reflective layer.

Claims

1. A microelectromechanical (MEMS) device comprising:

at least one electrode;

a first reflective layer; and

a movable reflective element comprising;

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

a second reflective layer mechanically coupled to the flexible dielectric layer.

2. The MEMS device of claim 1, wherein the second reflective layer is not spaced from the flexible dielectric layer.

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

4. The MEMS device of claim 1, further comprising an insulating layer between the first reflective layer and the second reflective layer.

5. The MEMS device of claim 4, wherein the second reflective layer contacts the insulating layer when the reflective element is in a first position relative to the first reflective layer and wherein the second reflective layer does not contact the insulating layer when the reflective element is in a second position relative to the first reflective layer.

6. The MEMS device of claim 4, wherein a first portion and a second portion of the second reflective layer contact the insulating layer when the reflective element is in a first position relative to the first reflective layer, wherein the first portion does not contact the insulating layer when the reflective element is in a second position relative to the first reflective layer, and wherein the second portion contacts the insulating layer when the reflective element is in the second position.

7. The MEMS device of claim 1, further comprising a plurality of supports mechanically coupling the first reflective layer and the reflective element.

8. The MEMS device of claim 7, further comprising a plurality of support structures on a side of the plurality of supports opposite the first reflective layer.

9. The MEMS device of claim 8, wherein the plurality of support structures comprises a conductive material.

10. The MEMS device of claim 8, wherein the plurality of support structures comprises a conductive material on the plurality of supports and a rigid dielectric material on the conductive material.

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, the supporting

means mechanically coupled to the second reflecting means, 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 reflective 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 at least one electrode;

providing a first reflective layer;

forming a sacrificial layer over the first reflective layer;

forming a reflective element over the sacrificial layer, the reflective element substantially parallel to the first reflective layer, wherein forming the reflective element comprises;

forming a second reflective layer over the sacrificial layer; and

forming a flexible dielectric layer over the second reflective layer; and

removing the sacrificial layer such that the flexible dielectric layer is responsive to voltages applied to the at least one electrode by flexing to move the reflective element in a direction generally perpendicular to the first reflective layer.

24. The method of claim 23, further comprising forming an insulating layer over the first reflective layer prior to forming the sacrificial layer.

25. The method of claim 24, wherein forming the second reflective layer comprises depositing a material of the second reflective layer and patterning the material of the second reflective layer, the patterning of the material of the second conductive layer exposing portions of the sacrificial layer.

26. The method of claim 24, wherein forming the second reflective layer comprises depositing a material of the second reflective layer and patterning the material of the second reflective layer, the patterning of the material of the second conductive layer leaving the sacrificial layer substantially covered.

27. The method of claim 23, further comprising forming a plurality of supports mechanically coupling the first reflective layer and the reflective element.

28. The method of claim 27, wherein forming the plurality of supports comprises:

forming a plurality of apertures through the sacrificial layer; and

forming a plurality of dielectric structures in the apertures.

29. The method of claim 28, wherein forming the plurality of dielectric structures in the apertures is performed while forming the flexible dielectric layer over the sacrificial layer.

30. The method of claim 27, further comprising forming a plurality of support structures over the plurality of supports.

31. The method of claim 30, wherein forming the plurality of support structures comprises:

forming a conductive layer over the plurality of supports; and

patterning the conductive layer.

32. The method of claim 30, wherein forming the plurality of support structures comprises:

forming a conductive layer over the plurality of supports;

depositing a rigid dielectric layer over the conductive layer;

patterning the rigid dielectric layer; and

patterning the conductive layer.

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