Method of using a preferentially deposited lubricant to prevent anti-stiction in micromechanical systems

• US 7,463,404 B2
• Filed: 11/02/2006
• Issued: 12/09/2008
• Est. Priority Date: 11/23/2005
• Status: Expired due to Fees

• Current Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Original Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Inventors: Chen, Dongmin, Xiong, Fulin
• Primary Examiner(s): Dang; Hung X.
• Assistant Examiner(s): Tra; Tuyen Q
• Application Number:
  US11/556,154
• Publication Number:
  US 20070115532A1
• Time in Patent Office: 768 Days
• Field of Search: 359/290, 359/291, 359/292, 359/293, 359/295, 359/298, 359/223, 359/224, 359/900, 438/115, 438/116, 257/682, 257/721
• US Class Current: 359/290
• 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 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

Embodiments of the present invention generally relate to a device that has an improved usable lifetime due to the presence of a lubricant that reduces the likelihood of stiction occurring between the various moving parts in an electromechanical device. Embodiments of the present invention also generally include a device, and a method of forming a device, that has one or more surfaces or regions that have a volume of lubricant disposed thereon that acts as a ready supply of “fresh” lubricant to prevent stiction occurring between interacting components found within the device. In one aspect, components within the volume of lubricant form a gas or vapor phase that reduces the chances of stiction-related failure in the formed device. In one example, aspects of this invention may be especially useful for fabricating and using micromechanical devices, such as MEMS devices, NEMS devices, or other similar thermal or fluidic devices.

Claims

1. A method of operating a micromechanical device, comprising biasing one or more electrodes that are disposed within a processing region, wherein biasing the one or more electrodes causes a moveable component having a first contact surface to interact with a second contact surface, and wherein one or more normal operating conditions cause a lubricant molecule, which has a head group that is adapted to bond to a first surface disposed in the processing region, to migrate from the first surface to a space formed between the first and second contact surfaces during normal operation.

2. The method of claim 1, wherein the one or more normal operating conditions are selected from a group consisting of biasing the one or more electrodes, and providing an ambient temperature between about 0°

C. and about 70°

C.

3. The method of claim 1, wherein the moveable component comprises a mirror.

4. The method of claim 1, wherein the micromechanical device is an optical image processor or a spatial light modulator.

5. The method of claim 1, wherein the lubricant molecules comprise a fluorinated compound that have a molecular weight greater than about 100 amu.

6. The method of claim 1, wherein the lubricant molecules have the head group that is selected from a group consisting of an oxysilane functional group, a trichlorosilane functional group and a carboxilate functional group.

7. The method of claim 1, wherein the temperature in the processing region during normal operation is between about 0°

C. and about 70°

C.

8. A method of operating a micromechanical device comprising:

biasing one or more electrodes that are disposed within a processing region, wherein biasing the one or more electrodes causes a moveable component having a first contact surface to interact with a second contact surface; and

delivering an amount of energy to a process surface that is contained within the processing region from an energy source that is in thermal communication with the process surface, wherein a plurality of lubricant molecules disposed on the process surface are adapted to detach from the process surface when exposed to the amount of energy and migrate to a position between the first contact surface and the second contact surface.

9. The method of claim 8, wherein the moveable component comprises a mirror.

10. The method of claim 8, wherein the micromechanical device is an optical image processor or a spatial light modulator.

11. The method of claim 8, wherein the plurality of lubricant molecules that are a fluorinated compound that have a molecular weight greater than about 100 amu.

12. The method of claim 8, wherein the energy source is adapted to deliver optical radiation or thermal energy to the lubricant molecules on the process surface.

13. The method of claim 8, further comprising forming the plurality of lubricant molecules which comprise a head group that is adapted to bond to the process surface.

14. The method of claim 13, wherein the head group is selected from a group consisting of an oxysilane functional group, a trichlorosilane functional group and a carboxilate functional group.

15. A method of operating a micromechanical device comprising:

positioning a micromechanical device in a first position, wherein the micromechanical device comprises;

a first contact surface that is disposed in a processing region;

an electrode coupled to a base;

a mirror coupled to the base and having a conductive region, a reflective mirror surface and a second contact surface, wherein the second contact surface interacts with the first contact surface during device operation;

a power supply that is in electrical communication with the conductive region and the electrode; and

a plurality of lubricant molecules that each have a head group that is adapted to bond to a process surface, wherein the process surface is a portion of one or more walls that enclose the processing region;

positioning a light source so that a portion of the optical radiation emitted by the light source is reflected by the mirror surface; and

biasing the electrode relative to the conductive region to a potential that causes the mirror to move to a desired position and that causes the first contact surface to interact with the second contact surface,

wherein during normal operation of the micromechanical device the plurality of lubricant molecules migrate from the process surface to a space formed between the first and second contact surfaces.

16. The method of claim 15, wherein the plurality of lubricant molecules are a fluorinated compound that has a molecular weight greater than about 100 amu.

17. The method of claim 15, wherein the micromechanical device is an optical image processor or a spatial light modulator.

18. The method of claim 15, wherein the head group is selected from a group consisting of an oxysilane functional group, a trichlorosilane functional group and a carboxilate functional group.