MICROELECTROMECHANICAL DEVICE WITH OPTICAL FUNCTION SEPARATED FROM MECHANICAL AND ELECTRICAL FUNCTION

• US 20090009845A1
• Filed: 07/02/2007
• Published: 01/08/2009
• Est. Priority Date: 07/02/2007
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm, Inc.
• Inventors: Mignard, Marc, Endisch, Denis
• Granted Patent: US 7,630,121 B2
• Time in Patent Office: Days
• US Class Current: 359/237
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 3/0083 Optical properties
• 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

In certain embodiments, a microelectromechanical (MEMS) device comprises a substrate having a top surface, a movable element over the substrate, and an actuation electrode disposed laterally from the reflective surface. The movable element comprises a deformable layer and a reflective element mechanically coupled to the deformable layer. The reflective element includes a reflective surface. The movable element is responsive to a voltage difference applied between the actuation electrode and the movable element by moving in a direction generally perpendicular to the top surface of the substrate.

Claims

1. A microelectromechanical (MEMS) device comprising:

a substrate having a top surface;

a movable element over the substrate, the movable element comprising a deformable layer and a reflective element mechanically coupled to the deformable layer, the reflective element including a reflective surface; and

an actuation electrode disposed laterally from the reflective surface, the movable element responsive to a voltage difference applied between the actuation electrode and the movable element by moving in a direction generally perpendicular to the top surface of the substrate.

2. The MEMS device of claim 1, wherein the reflective element is mechanically coupled to a top surface of the deformable layer.

3. The MEMS device of claim 1, wherein the reflective element is mechanically coupled to a bottom surface of the deformable layer.

4. The MEMS device of claim 1, wherein the movable element further comprises at least one connecting element, the at least one connecting element mechanically coupling the reflective element to the deformable layer.

5. The MEMS device of claim 4, wherein a first connecting element is mechanically coupled to a first edge of the reflective element and a second connecting element is mechanically coupled to a second edge of the reflective element, the first edge substantially opposite the second edge.

6. The MEMS device of claim 4, wherein the reflective element has a plurality of edges and wherein the at least one connecting element mechanically couples each edge of the reflective element to the deformable layer.

7. The MEMS device of claim 4, wherein the at least one connecting element comprises at least one protrusion extending from the reflective element.

8. The MEMS device of claim 1, wherein the reflective surface is spaced from the deformable layer along a direction generally parallel to the top surface of the substrate.

9. The MEMS device of claim 1, wherein the actuation electrode is under at least a portion of the deformable layer.

10. The MEMS device of claim 1, wherein the top surface of the substrate is spaced from the reflective surface when an actuation voltage difference is applied between the actuation electrode and the movable element.

11. The MEMS device of claim 1, wherein a distance between the reflective surface and the top surface of the substrate is greater than a distance between the deformable layer and the top surface of the substrate.

12. The MEMS device of claim 1, wherein a distance between the deformable layer and the top surface of the substrate is greater than a distance between the reflective surface and the top surface of the substrate.

13. The MEMS device of claim 1, wherein the movable element is responsive to a voltage difference applied between the actuation electrode and the movable element by moving from a first position in which a portion of the movable element is not in contact with a surface of the device to a second position in which the portion is in contact with the surface of the device.

14. The MEMS device of claim 13, wherein the surface of the device comprises a top surface of the substrate.

15. The MEMS device of claim 13, wherein the surface of the device comprises a top surface of the actuation electrode.

16. The MEMS device of claim 13, wherein the surface of the device comprises a top surface of an insulating layer between the actuation electrode and the deformable layer.

17. The MEMS device of claim 1, wherein application of a voltage difference between the actuation electrode and the movable element causes displacement of the deformable layer and displacement of the reflective surface, the displacement of the deformable layer parallel to the displacement of the reflective surface, the displacement of the deformable layer on a different plane than the displacement of the reflective surface.

18. The MEMS device of claim 1, further comprising an other actuation electrode over the movable element, the movable element responsive to a voltage difference applied between the other actuation electrode and the movable element by moving in a direction generally perpendicular to the top surface of the substrate.

19. The MEMS device of claim 18, further comprising an insulating layer between the other actuation electrode and the movable element.

20. The MEMS device of claim 19, wherein the insulating layer is formed on an upper surface of the movable element.

21. The MEMS device of claim 19, wherein the insulating layer is formed on a lower surface of the other actuation electrode.

22. 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.

23. The MEMS device of claim 22, further comprising a driver circuit configured to send at least one signal to the display.

24. The MEMS device of claim 23, further comprising a controller configured to send at least a portion of the image data to the driver circuit.

25. The MEMS device of claim 22, further comprising an image source module configured to send said image data to said processor.

26. The MEMS device of claim 25, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

27. The MEMS device of claim 22, further comprising an input device configured to receive input data and to communicate said input data to said processor.

28. A microelectromechanical (MEMS) device comprising:

means for moving a portion of the device, the moving means comprising means for deforming and means for reflecting;

means for supporting the moving means; and

means for actuating the moving means, the actuating means disposed laterally from the reflecting means.

29. The MEMS device of claim 28, wherein the supporting means comprises a substrate.

30. The MEMS device of claim 28, wherein the moving means comprises a movable element.

31. The MEMS device of claim 28, wherein the deforming means comprises a deformable layer.

32. The MEMS device of claim 28, wherein the reflective means comprises a reflective element including a reflective surface.

33. The MEMS device of claim 28, wherein the actuating means comprises an actuation electrode.

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

forming an actuation electrode over a substrate;

forming a sacrificial layer over the actuation electrode;

forming a deformable layer over the sacrificial layer;

forming a reflective element over the sacrificial layer and mechanically coupled to the deformable layer, the reflective element including a reflective surface disposed laterally from the actuation electrode; and

removing the sacrificial layer.

35. A MEMS device fabricated by the method of claim 34.

36. A method of modulating light, the method comprising:

providing a display element comprising a substrate, a movable element over the substrate, and an actuation electrode, the movable element comprising a deformable layer and a reflective element, the reflective element mechanically coupled to the deformable layer and including a reflective surface, the actuation electrode disposed laterally from the reflective surface; and

applying a voltage to the actuation electrode, the voltage generating an attractive force on the movable element, thereby causing the movable element to move towards the substrate.