MEMS device deflection stop

• US 7,252,395 B2
• Filed: 03/10/2006
• Issued: 08/07/2007
• Est. Priority Date: 11/21/2001
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Knipe, Richard L., DiCarlo, Anthony, Oden, Patrick I., Mezenner, Rabah, Huffman, James D.
• Primary Examiner(s): Perkey; W. B.
• Assistant Examiner(s): SEVER, ANDREW T
• Application Number:
  US11/372,686
• Publication Number:
  US 20060152690A1
• Time in Patent Office: 515 Days
• Field of Search: 359/291, 359/295, 359/846, 359290-292, 359/849, 359/850, 359/872, 359/876, 359/318, 359/198, 359/212, 359/213, 359220-226, 347/239, 353/98, 353/99, 348/770, 348/771
• US Class Current: 353/99
• CPC Class Codes: B81B 3/0035 Constitution or structural means for controlling the movement of the flexible or deformable elements
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: Y10T 428/22 Nonparticulate element embedded or inlaid in substrate and visible

Abstract

A micromirror array fabricated on a semiconductor substrate. The array is comprised of three operating layers. An addressing layer is fabricated on the substrate. A hinge layer is spaced above the addressing layer by an air gap. A mirror layer is spaced over the hinge layer by a second air gap. The hinge layer has a hinge under and attached to the mirror, the hinge permitting the mirror to tilt. The hinge layer further has spring tips under the mirror, which are attached to the addressing layer. These spring tips provide a stationary landing surface for the mirror.

Claims

1. A micromechanical device comprising:

a substrate;

a member disposed apart from the substrate and operable to deflect relative to said substrate about an axis;

an intermediate layer disposed apart from said substrate and said member, said intermediate layer having at least one electrode and at least one spring tip operable to contact said member upon said deflection of said member; and

wherein said electrode is located closer than said spring tip to a projection of said axis onto the plane of the intermediate layer.

2. The micromechanical device of claim 1, wherein said electrode is operable to attract said member.

3. The micromechanical device of claim 1, comprising at least two spring tips.

4. The micromechanical device of claim 1, wherein the member is a micromirror.

5. The micromechanical device of claim 1, wherein the device is a micromirror array.

6. A method of forming a micromirror device, the method comprising:

providing a substrate;

forming an intermediate layer disposed apart from said substrate

forming a member disposed apart from the intermediate layer and said substrate and operable to deflect relative to said substrate about an axis;

wherein forming an intermediate layer comprises forming said intermediate layer having at least one electrode and at least one spring tip operable to contact said member upon said deflection of said member; and

wherein said electrode is formed closer than said spring tip to a projection of said axis onto the plane of the intermediate layer.

7. The method of claim 6, wherein said forming an intermediate layer comprises forming said electrode operable to attract said member.

8. The method of claim 6, wherein said forming an intermediate layer comprises forming two spring tips.

9. The method of claim 6, wherein said forming a member comprises forming a micromirror.

10. The method of claim 6, wherein said forming an intermediate layer comprises forming said device wherein said member is a micromirror array.

11. A display system comprising:

a micromirror device comprising;

a substrate;

a member disposed apart from the substrate and operable to deflect relative to said substrate about an axis;

an intermediate layer disposed apart from said substrate and said member, said intermediate layer having at least one electrode and at least one spring tip operable to contact said member upon said deflection of said member; and

wherein said electrode is located closer than said spring tip to a projection of said axis onto the plane of the intermediate layer;

a light source for providing a beam of light to illuminate said micromirror device, said micromirror device spatially modulating said beam of light such that said modulated beam of light forms an image on an image plane.

12. The micromirror device of claim 11, wherein said electrode is operable to attract said member.

13. The micromirror device of claim 11, wherein the member comprises at least two spring tips.

14. The micromirror device of claim 11, wherein the member comprises two spring tips.

15. The micromirror device of claim 11, wherein the member is a micromirror.