Self-assembled monolayer coating for micro-mechanical devices

• US 5,523,878 A
• Filed: 06/30/1994
• Issued: 06/04/1996
• Est. Priority Date: 06/30/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Wallace, Robert M., Webb, Douglas A., Gnade, Bruce E.
• Primary Examiner(s): Ben, Loha
• Application Number:
  US08/268,485
• Time in Patent Office: 705 Days
• Field of Search: 359/224, 359/226, 359/230, 359/213, 359/290, 359/291, 359/292, 359/293, 359/295, 359/298, 359/846, 359/847, 427/534, 427/162
• US Class Current: 359/290
• 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
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths

Abstract

A method of forming of a monomolecular coating (19) for surfaces of contacting elements (11, 17) of micro-mechanical devices (10), specifically, devices that have moving elements that contact other elements and that tend to stick as a result of the contact. The method uses liquid deposition, with the device being placed in a solution that contains a precursor to the formation of the coating. The precursor is chosen based on coordination chemistry between the precursor and the surface to be coated.

Claims

1. An improved micro-mechanical device of a type having relatively moving elements, portions of which may come into contact with each other and thereafter adhere together at their contacting surfaces, wherein the improvement comprises:

a self-assembled monomolecular layer on at least one of said contacting surfaces, said layer having been formed from a precursor solution that contains a precursor substance;

wherein said contacting surfaces are comprised of a material selected from the group consisting of metal and aluminum oxide; and

wherein said precursor solution contains a precursor substance selected from the group consisting of;

hydrocarbon, fluorocarbon, n-alkanoic acid, alkyl oxalic acid, hydroxamic acid, and phosphonic acid.

2. The device of claim 1, wherein said precursor substance is selected on the basis of coordination chemistry between said precursor and the surface to be coated.

3. The device of claim 1, wherein said precursor solution further contains a solvent.

4. The device of claim 1, wherein said precursor solution further contains a surfactant for decreasing the surface tension of said solution.

5. A method of preventing sticking of contacting elements of a micro-mechanical device, comprising the steps of:

at least partially fabricating said micro-mechanical device, such that at least one of said contacting elements is substantially fabricated from materials selected from the group consisting of metal and aluminum oxide;

immersing at least the surface of said at least one contacting element in a precursor solution containing a precursor substance, such that molecules of said precursor substance bind to said surface as a self-assembled monolayer;

wherein said precursor solution contains a precursor substance selected from the group consisting of;

hydrocarbon, fluorocarbon, n-alkanoic acid, alkyl oxalic acid, and hydroxamic acid.

6. The method of claim 5, wherein said precursor solution further contains a solvent.

7. The method of claim 5, wherein said precursor solution further contains a surfactant for decreasing the surface tension of said solution.

8. A digital micro-mirror device, comprising:

a substrate upon which the following elements are fabricated;

at least one landing electrode, a support post, a hinge extending from said support post, a mass attached to said hinge, wherein said hinge is deformable so as to permit said mass to contact said landing electrode upon being subjected to an applied force; and

wherein the contacting surface of said mass or of said landing electrode, or both of said contacting surfaces, are coated with a self-assembled monomolecular layer; and

wherein said self-assembled monomolecular layer is made from an n-alkanoic precursor.