Electromechanical devices having support structures

• US 8,344,470 B2
• Filed: 05/02/2011
• Issued: 01/01/2013
• Est. Priority Date: 07/22/2005
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Sampsell, Jeffrey B., Chui, Clarence, Kothari, Manish, Miles, Mark W., Sasagawa, Teruo, Chung, Wonsuk, Tung, Ming-Hau
• Primary Examiner(s): Fulk, Steven J
• Application Number:
  US13/099,221
• Publication Number:
  US 20110205197A1
• Time in Patent Office: 610 Days
• Field of Search: 257/432, 257/E31.127, 359/247
• US Class Current: 257/432
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 2203/0307 Anchors
• CPC Class Codes: B81B 2203/053 Translation according to an axis perpendicular to the substrate
• CPC Class Codes: B81B 3/007 For controlling stiffness, e.g. ribs
• 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

Embodiments of MEMS devices comprise a conductive movable layer spaced apart from a conductive fixed layer by a gap, and supported by rigid support structures, or rivets, overlying depressions in the conductive movable layer, or by posts underlying depressions in the conductive movable layer. In certain embodiments, both rivets and posts may be used. In certain embodiments, these support structures are formed from rigid inorganic materials, such as metals or oxides. In certain embodiments, etch barriers may also be deposited to facilitate the use of materials in the formation of support structures which are not selectively etchable with respect to other components within the MEMS device.

Claims

1. An electromechanical device, comprising:

a substrate;

an electrode layer located over the substrate;

a conductive movable layer located over the electrode layer, wherein the movable layer is generally spaced apart from the electrode layer by an air gap, and wherein the conductive movable layer is electrostatically displaceable towards the electrode; and

support structures underlying and extending adjacent at least a portion of the movable layer, each of the support structures having a depression in an upper surface of the support structure, wherein a portion of the movable layer extends between at least two of the support structures.

2. The device of claim 1, wherein the movable layer comprises a reflective sublayer facing the electrode layer, and a mechanical sublayer located over the reflective sublayer.

3. The device of claim 2, additionally comprising a partially reflective layer located on the opposite side of the gap as the reflective sublayer.

4. The device of claim 2, additionally comprising at least one stiffening structure formed on the opposite side of the reflective sublayer from the electrode layer.

5. The device of claim 4, wherein the stiffening structure comprises the same material as the support structure.

6. The device of claim 1, additionally comprising at least one support structure located over the movable layer, wherein the at least one overlying support structure at least partially overlies at least one support structure underlying the substrate.

7. The device of claim 1, additionally comprising a partially reflective layer located over the substrate, wherein the partially reflective layer is located on the same side of the air gap as the electrode layer.

8. The device of claim 1, wherein the support structure comprises a metallic material.

9. The device of claim 1, wherein the support structure comprises an anodized material.

10. The device of claim 1, wherein the support structure comprises an inorganic material.

11. The device of claim 1, wherein the device comprises an interferometric modulator.

12. The device of claim 1, additionally comprising:

a processor that is configured to communicate with at least one of said electrode layer and said movable layer, said processor being configured to process image data; and

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

13. The device of claim 12, further comprising a driver circuit configured to send at least one signal to at least one of said electrode layer and said movable layer.

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

15. The device of claim 12, further comprising an image source module configured to send said image data to said processor.

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

17. The device of claim 12, further comprising an input device configured to receive input data and to communicate said input data to said processor.

18. The device of claim 1, wherein the depression in the upper surface of the support structure is located in an interior portion of the upper surface.

19. An electromechanical device, comprising:

an electrode located over a substrate;

a conductive movable layer spaced apart from the first electrode by an air gap, wherein the movable layer is electrostatically displaceable towards the electrode; and

means for supporting said movable layer over said first electrode, wherein said supporting means underlies and extends adjacent at least a portion of the movable layer, each of said supporting means comprising a depression in an upper surface, wherein a portion of the movable layer extends between two of said supporting means.

20. The device of claim 19, wherein the supporting means comprise at least two support structures formed over said substrate and underlying said the movable layer, wherein a portion of the movable layer extends between at least two of support structures.

21. The device of claim 19, wherein the depression in an upper surface of the supporting means is located in an interior portion of the upper surface.

22. An electromechanical device, comprising:

a substrate;

a partially reflective layer located over the substrate;

a conductive movable layer located over the partially reflective layer, wherein the movable layer is generally spaced apart from the partially reflective layer by an air gap, and wherein the conductive movable layer is electrostatically displaceable towards the partially reflective layer; and

support structures underlying and extending adjacent at least a portion of the movable layer, each of the support structures having a depression in an interior portion of an upper surface of the support structure, wherein a portion of the movable layer extends between at least two of the support structures.

23. The device of claim 22, additionally comprising an electrode layer located on the opposite side of the gap as the conductive movable layer.

24. The device of claim 22, wherein the support structure comprises a metallic material.

25. The device of claim 22, wherein the support structure comprises an anodized material.

26. The device of claim 22, wherein the support structure comprises an inorganic material.