MULTILAYERED DEFORMABLE ELEMENT WITH REDUCED MEMORY PROPERTIES IN A MEMS DEVICE

• US 20090231673A1
• Filed: 03/12/2008
• Published: 09/17/2009
• Est. Priority Date: 03/12/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Hornbeck, Larry Joseph, Jacobs, Simon Joshua, Oden, Patrick Ian
• Granted Patent: US 8,472,100 B2
• Time in Patent Office: Days
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A deformable element for use in microelectromechanical systems comprises a core layer and a protective layer. The protective layer is capable of deterring combinations of undesired chemical components in operational environments with the core layer of the deformable element.

Claims

1. A microelectromechanical device, comprising:

a substrate;

a deformable element held on the substrate; and

a protective layer for blocking a combination of an undesired chemical component with the deformable element, wherein said undesired chemical component is capable of changing a mechanical property of the deformable element if combined with the deformable element.

2. The device of claim 1, wherein said protective layer is a thin film formed by a standard thin-film fabrication technique on a major surface of the deformable element;

and is physically connected to the major surface.

3. The device of claim 2, wherein said thin-film is composed of an electrically conductive or insulating material or a semiconductor material.

4. The device of claim 2, wherein the thin-film is a water barrier film capable of preventing the combination of water with the deformable element.

5. The device of claim 2, wherein the thin-film is electrically insulting and comprises:

an opening in which an electrically conductive material is disposed.

6. The device of claim 1, wherein said protective layer comprises a getter material.

7. The device of claim 6, wherein said getter material is in a form of a thin-film that is disposed on a major surface of the deformable element.

8. The device of claim 1, wherein the deformable element is a torsional hinge to which a reflective mirror plate is attached such that the mirror plate is capable of rotating above the substrate.

9. The device of claim 1, wherein the protective layer comprises a protective film whose diffusion coefficient varies with a temperature at which the protective film is operated.

10. A microelectromechanical device, comprising:

a substrate;

a deformable element held above the substrate; and

a thin film of getter material disposed on a major surface of the deformable hinge.

11. The device of claim 10, wherein the thin-film of the getter material is physically contacted to the major surface of the deformable element and covers substantially all of said major surface of the deformable element.

12. The device of claim 10, further comprising:

a protective layer comprising an electrically conductive or insulating material or a semiconductor material, wherein the protective layer is formed on the deformable element; and

wherein the protective layer is laminated between said major surface of the deformable element and the thin-film of the getter material.

13. The device of claim 10, further comprising:

a protective layer comprising an electrically conductive or insulating material or a semiconductor material, wherein the protective layer is formed on the deformable element; and

wherein the thin-film of the getter material is laminated between the protective layer and said major surface of the deformable element.

14. The device of claim 13, wherein said protective layer is electrically insulating and comprises an opening in which an electrically conductive material is disposed.

15. The device of claim 13, wherein the protective layer is a barrier layer capable of deterring a combination of an undesired chemical component in an operational environment to the deformable element;

and wherein said undesired chemical component is capable of changing a mechanical property of the deformable element when combined with the deformable element.

16. The device of claim 13, wherein the protective layer is a water barrier layer capable of deterring a combination of water with the deformable element.

17. The device of claim 13, wherein said protective layer comprises a protective material, wherein said protective material is chemically or physically bonded to a major surface of the deformable element.

18. The device of claim 13, wherein the deformable element is a torsional hinge to which a reflective mirror plate is attached such that the mirror plate is capable of rotating above the substrate.

19. The device of claim 13, wherein the protective film whose diffusion coefficient varies with a temperature at which the protective film is operated.

20. A microelectromechanical device, comprising:

a substrate; and

a deformable element held on the substrate, comprising;

a core layer; and

a protective layer disposed on a major surface of the core layer, wherein the protective layer has a first diffusion coefficient at a first temperature range and a second diffusion coefficient at a temperature range that different from the first temperature range.

21. The device of claim 20, wherein the first temperature range is from the room temperature to 70°

C.; and

wherein the second temperature range is from 70°

C. to 500°

C.

22. The device of claim 21, wherein the first diffusion coefficient is 20% or less of the second diffusion coefficient.

23. The device of claim 21, wherein the deformable element is a deformable hinge to which a reflective mirror plate of micromirror device is attached such that mirror plate is capable of moving relative to the substrate.

24. The device of claim 23, wherein the protective layer is a thin-film that comprises:

electrically conductive or insulating material or a semiconductor material or a getter material.

25. The device of claim 24, wherein the protective layer comprises a water getter material.