Method of producing micromechanical devices

• US 5,411,769 A
• Filed: 09/29/1993
• Issued: 05/02/1995
• 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): PIANALTO, BERNARD D
• Application Number:
  US08/128,459
• Time in Patent Office: 580 Days
• Field of Search: 427/162, 427/301, 427/307, 427/314, 427/539, 427/294, 427/534, 427/255.6
• US Class Current: 427/534
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 3/0005 Anti-stiction coatings
• CPC Class Codes: B81C 1/0096 For avoiding stiction when the device is in use, i.e. after manufacture has been completed
• 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. The invention disclosed here details how to do so by building the device to be passivated, cleaning the surface to be passivated, activating the surface, heating it along with the material to be used as the monolayer, exposing a vapor of the material to the surface and evacuating the excess material, leaving only the monolayer.

Claims

1. A method for producing a low surface energy wear resistant thin film on the surface of a micromechanical device comprising the steps of:

a) cleaning said device;

b) activating the surface of said cleaned device;

c) heating said activated surface;

d) heating a source material to produce a vapor, wherein said source material is a long-chain aliphatic halogenated polar compound; and

e) exposing said activated surface to said source material vapor to deposit a passivating layer on said surface.

2. The method of claim 1 wherein said exposing step deposits an oriented monolayer of said source material.

3. The method of claim 1 wherein said micromechanical device is a deformable mirror device.

4. The method of claim 1 wherein said activating step comprises the step of placing said device into an oxygen plasma.

5. The method of claim 1 wherein said step of heating said device surface and said source material, and said step of exposing the device surface to a source material vapor comprises the steps of placing said device and said source material in a covered container and then placing said covered container in a vacuum oven and heating said vacuum oven.

6. The method of claim 1 wherein said long-chain aliphatic halogenated polar compound is perfluordecanoic acid (PFDA).

7. The method of claim 1 further comprising the step of removing excess long-chain aliphatic halogenated polar compound from said device.

8. The method of claim 7 wherein said step of removing excess long-chain aliphatic halogenated polar compound from said device comprises evacuating a chamber containing said device.

9. A method for producing a low surface energy wear resistant thin film on the surface of a micromechanical device comprising the steps of:

a) cleaning said device;

b) activating the surface of said cleaned device;

c) heating said activated surface;

d) heating a source material to produce a vapor; and

e) exposing said activated surface to said vapor to deposit a passivating layer on said activated surface.

10. The method of claim 9 wherein said exposing step deposits an oriented monolayer of source material.

11. The method of claim 9 wherein said device is a deformable mirror device.

12. The method of claim 9 further comprising the step of removing excess source material from said device.

13. The method of claim 12 wherein said step of removing excess source material from said device comprises evacuating a chamber containing said device.

14. The method of claim 9 wherein said step of heating said device surface and said source material, and said step of exposing the device surface to a source material vapor comprises the steps of placing said device and said source material in a covered container and then placing said covered container in a vacuum oven and heating said vacuum oven.

15. The method of claim 9 wherein said activating step comprises the step of placing said device in an oxygen plasma.

16. A method for producing a low surface energy wear resistant oriented monolayer on the surface of a deformable micromirror device comprising the steps of:

a) cleaning said device;

b) placing said cleaned device in an oxygen plasma to activate the surface of said cleaned device;

c) placing said device and a long-chain aliphatic halogenated polar compound in a covered container;

d) heating said covered container in a vacuum oven to produce a vapor of said long-chain aliphatic halogenated polar compound;

e) exposing said activated surface to said long-chain aliphatic halogenated polar compound vapor to deposit a passivating layer on said surface.

17. The method of claim 16 wherein said long-chain aliphatic halogenated polar compound is perfluordecanoic acid.

18. The method of claim 16 further comprising the step of removing excess long-chain aliphatic halogenated polar compound from said device.

19. The method of claim 18 wherein said step of removing excess long-chain aliphatic halogenated polar compound from said device comprises evacuating a chamber containing said device.