Low surface energy passivation layer for micromechanical devices

• US 5,602,671 A
• Filed: 02/04/1994
• Issued: 02/11/1997
• Est. Priority Date: 11/13/1990
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Hornbeck, Larry J.
• Primary Examiner(s): Phan, James
• Application Number:
  US08/193,689
• Time in Patent Office: 1,103 Days
• Field of Search: 359/223, 359/224, 359/230, 359/233, 359/884, 359/292-293, 348/771, 427/162, 427/255.6, 437/225, 437/228, 310/40 MM
• US Class Current: 359/224.1
• CPC Class Codes: B81B 3/0005 Anti-stiction coatings
• CPC Class Codes: B81C 2201/112 Depositing an anti-stiction or passivation coating, e.g. on the elastic or moving parts
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

It is possible to use an oriented monolayer to limit the Van der Waals forces between two elements by passivation. An oriented monolayer (34) is formed on a surface of a micromechanical device. When the surface comes in contact with another surface, the oriented monolayer decreases the Van der Waals forces to reduce the attraction between the surfaces.

Claims

1. An electronic device comprising:

at least one address electrode on a substrate;

at least one landing electrode on said substrate adjacent said address electrode;

a support layer formed upon said substrate such that at least one gap exists in said support layer exposing said address electrode and said landing electrode;

at least one hinge formed on said support layer such that said hinge is suspended over said gap;

at least one deflection element formed upon said at least one hinge and supported over said gap by said hinge, wherein a mutual attraction exists between said deflection element and said landing electrode when said deflection element is in contact with said landing electrode; and

an oriented monolayer formed upon said landing electrode whereby said mutual attraction between said landing electrode and said deflection element is reduced, wherein said oriented monolayer is comprised of a COOH terminal group attached to said landing electrode, a carbon chain connected to said COOH terminal group by a first end, and a CF₃ terminal group connected to a second end of said carbon chain.

2. An electronic device comprising:

a micromechanical DMD which includes a deflection element selectively electrostatically movable into contact with a landing electrode, and

an oriented monolayer formed on at least a region of the landing electrode which is contactable by the deflection element to reduce mutual attraction between contacted deflection element and landing electrode, wherein said oriented monolayer is comprised of a COOH terminal group attached to said landing electrode, a carbon chain connected to said COOH terminal group by a first end, and a CF₃ terminal group connected to a second end of said carbon chain.

3. A micromechanical device comprising:

a first surface;

a second surface, wherein a mutual attractive force is created when said first surface and said second surface are in contact; and

an oriented monolayer formed on said first surface, whereby said mutual attraction between said first surface and said second surface is reduced, wherein said oriented monolayer is comprised of a COOH terminal group attached to said first surface, a carbon chain connected to said COOH terminal group by a first end, and a CF₃ terminal group connected to a second end of said carbon chain.

4. The micromechanical device of claim 3 wherein said device is a deformable micromirror device.

5. The micromechanical device of claim 3 wherein said first surface is a landing electrode of a deformable micromirror device.

6. The micromechanical device of claim 3 wherein said second surface is a deflection element of a deformable micromirror device.

7. The micromechanical device of claim 3 wherein said device is a micro-motor.

8. The micromechanical device of claim 3 wherein said device is a micro-gear.