Apparatus and method for reducing slippage between structures in an interferometric modulator

• US 20060067649A1
• Filed: 08/12/2005
• Published: 03/30/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Floyd, Philip D., Cummings, William J., Tung, Ming-Hau, Arbuckle, Brian W.
• Granted Patent: US 7,630,119 B2
• Time in Patent Office: Days
• US Class Current: 385/147
• 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 support structure within an interferometric modulator device may contact various other structures within the device. Increased bond strengths between the support structure and the other structures may be achieved in various ways, such as by providing roughened surfaces and/or adhesive materials at the interfaces between the support structures and the other structures. In an embodiment, increased adhesion is achieved between a support structure and a substrate layer. In another embodiment, increased adhesion is achieved between a support structure and a moveable layer. Increased adhesion may reduce undesirable slippage between the support structures and the other structures to which they are attached within the interferometric modulator.

Claims

1. A microelectromechanical systems (MEMS) device, comprising:

a substrate layer comprising a first reflective surface;

a movable layer comprising a second reflective surface, the second reflective surface being spaced from the first reflective surface to thereby define a cavity;

a support structure positioned at a side of the cavity between the substrate layer and the moveable layer; and

a bond between the support structure and at least one of the substrate layer and the moveable layer;

the bond being configured to increase adhesion between the support structure and at least one of the substrate layer and the moveable layer.

2. The MEMS device of claim 1, comprising an interferometric modulator.

3. The MEMS device of claim 1, wherein the bond comprises a roughened interface between the support structure and at least one of the substrate layer and the moveable layer.

4. The MEMS device of claim 3, wherein the bond is between the support structure and the substrate layer.

5. The MEMS device of claim 4, wherein the substrate layer comprises a transparent substrate underlying the first reflective surface.

6. The MEMS device of claim 5, wherein the roughened interface is between the support structure and the transparent substrate.

7. The MEMS device of claim 5, wherein the roughened interface is between the support structure and the first reflective surface.

8. The MEMS device of claim 3, wherein the bond is between the support structure and the moveable layer.

9. The MEMS device of claim 8, wherein the second reflective surface is suspended from the moveable layer.

10. The MEMS device of claim 1, wherein the bond comprises an adhesive layer between the support structure and at least one of the substrate layer and the moveable layer.

11. The MEMS device of claim 10, wherein the adhesive layer comprises aluminum.

12. The MEMS device of claim 10, wherein the adhesive layer is between the support structure and the substrate layer.

13. The MEMS device of claim 12, wherein the substrate layer comprises a transparent substrate underlying the first reflective surface.

14. The MEMS device of claim 13, wherein the adhesive layer is between the support structure and the transparent substrate.

15. The MEMS device of claim 13, wherein adhesive layer is between the support structure and the first reflective surface.

16. The MEMS device of claim 10, wherein the adhesive layer is between the support structure and the moveable layer.

17. The MEMS device of claim 16, wherein the second reflective surface is suspended from the moveable layer.

38. A display device comprising the interferometric modulator of claim 2.

39. The display device of claim 38, further comprising:

a display;

a processor that is in electrical communication with the display, the processor being configured to process image data;

a memory device in electrical communication with the processor.

40. The display device of claim 39, further comprising:

a driver circuit configured to send at least one signal to the display.

41. The display device of claim 40, further comprising:

a controller configured to send at least a portion of the image data to the driver circuit.

42. The display device of claim 39, further comprising:

an image source module configured to send the image data to the processor.

43. The display device of claim 42, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

44. The display device of claim 39, further comprising:

an input device configured to receive input data and to communicate the input data to the processor.

18. An interferometric modulator comprising:

a means for supporting a moveable layer over a fixed layer; and

a means for bonding the support means to at least one of the fixed layer and the moveable layer;

the bonding means being configured to provide improved adhesion between the support means and at least one of the fixed layer and the moveable layer.

19. The interferometric modulator of claim 18, wherein the bonding means comprises an adhesive.

20. The interferometric modulator of claim 18, wherein the bonding means comprises a roughened interface between the support means and at least one of the fixed layer and the moveable layer.

21. The interferometric modulator of claim 18, wherein the support means comprises a post.

22. A method of making an interferometric modulator, comprising:

forming a substrate layer, the substrate layer comprising a first reflective surface;

treating at least a portion of a support region of the substrate layer to form a treated support region; and

forming a support structure on the treated support region;

the treated support region being configured to increase adhesion between the substrate layer and the support structure.

23. The method of claim 22, wherein treating comprises roughening at least a portion of the support region of the substrate layer.

24. The method of claim 23, wherein roughening comprises etching the support region of the substrate layer.

25. The method of claim 23, wherein roughening comprises roughening a portion of the first reflective surface.

26. The method of claim 22, wherein treating comprises depositing an adhesive over at least a portion of the support region of the substrate layer.

27. The method of claim 22, further comprising depositing a sacrificial layer over the substrate layer.

28. The method of claim 27, further comprising depositing a second reflective layer over the sacrificial layer.

29. The method of claim 28, further comprising removing the sacrificial layer to form a cavity positioned between the first reflective layer and the second reflective layer.

30. An interferometric modulator made by the method of claim 22.

31. A method of making an interferometric modulator, comprising:

forming a substrate layer;

forming a support structure on the substrate layer;

treating the support structure to form a treated support structure; and

forming a moveable layer on the treated support structure.

32. The method of claim 31, wherein treating comprises roughening at least a portion of the support structure.

33. The method of claim 31, wherein treating comprises depositing an adhesive over at least a portion of the support structure.

34. The method of claim 31, further comprising forming a reflective layer on the substrate layer.

35. The method of claim 34, further comprising depositing a sacrificial layer over the first reflective layer.

36. The method of claim 35, further comprising removing the sacrificial layer to form a cavity positioned between the reflective layer and the moveable layer.

37. An interferometric modulator made by the method of claim 31.