PREFERENTIALLY DEPOSITED LUBRICANT TO PREVENT ANTI-STICTION IN MICROMECHANICAL SYSTEMS

• US 20070117244A1
• Filed: 11/02/2006
• Published: 05/24/2007
• Est. Priority Date: 11/23/2005
• Status: Active Grant

• Current Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Original Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Inventors: Chen, Dongmin, Xiong, Fulin, Worley, William
• Granted Patent: US 7,723,812 B2
• Time in Patent Office: Days
• US Class Current: 438/50
• 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

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 micromechanical device assembly, comprising:

one or more walls that form a processing region;

a storage surface that is disposed within the processing region;

a first contact surface disposed within the processing region;

a moveable component disposed within the processing region and having a second contact surface, wherein the second contact surface interacts with the first contact surface during device operation; and

a first lubricant layer disposed on the storage surface, wherein the lubricant layer includes a plurality of lubricant molecules preferentially bonded to the storage surface and is adapted to reduce stiction-related forces between the first contact surface and the second contact surface.

2. The micromechanical device assembly of claim 1, further comprising a base member that has a first side that includes the first contact surface and the storage surface.

3. The micromechanical device assembly of claim 1, wherein the storage surface comprises a portion of one of the one or more walls.

4. The micromechanical device assembly of claim 1, wherein the lubricant molecules that form the lubricant layer have a head group that is adapted to bond to the storage surface, wherein the storage surface comprises a material selected from a group consisting of silicon, silicon dioxide, titanium, aluminum and a glass material.

5. The micromechanical device assembly of claim 4, wherein the head group is selected from a group consisting of a oxysilane functional group, a trichlorosilane functional group and a carboxylate functional group.

6. The micromechanical device assembly of claim 1, wherein the lubricant molecules that form the lubricant layer have a head group that forms a weaker bond with the storage surface and a stronger bond with the first or second contact surface.

7. The micromechanical device assembly of claim 1, further comprising a heating assembly that comprises:

a heating element that is in thermal communication with the storage surface; and

a controller that is adapted to adjust the temperature of the storage surface so that a portion of the lubricant layer disposed thereon can desorb into the processing region.

8. The micromechanical device assembly of claim 1, wherein one of the one or more walls is optically transparent and has a first side that contains the storage surface.

9. The micromechanical device assembly of claim 1, further comprising a second lubricant layer disposed over the first contact surface or the second contact surface, wherein the second lubricant layer is a liquid lubricant layer that is adapted to reduce stiction-related forces between the first contact surface and the second contact surface.

10. The micromechanical device assembly of claim 1, wherein the first lubricant layer comprises:

a plurality of first lubricant molecules, wherein each first lubricant molecule has a first head group that is adapted to bond to the storage surface and an end group; and

a plurality of second lubricant molecules, wherein each second lubricant molecule has a second head group that is adapted to bond to the end group.

11. The micromechanical device assembly of claim 10, wherein each of the plurality of first lubricant molecules are cross-linked with each adjacent first lubricant molecule.

12. The micromechanical device assembly of claim 10, wherein each of the plurality of second lubricant molecules are cross-linked with each adjacent second lubricant molecule.

13. The micromechanical device assembly of claim 1, further comprising a channel formed in the at least one of the one or more walls, wherein the channel is in communication with an interior surface that contact the processing region and an exterior surface of the at least one of the one or more walls.

14. A micromechanical device assembly, comprising:

one or more walls that form a processing region, wherein at least a portion of one of the one or more walls is formed from an optically transparent material;

a process surface that is disposed within the processing region;

a micromechanical device positioned within the processing region, wherein the micromechanical device includes;

a first contact surface disposed within the processing region,

a moveable component having a second contact surface and a conductive region,

an electrode coupled to a base, and

a power supply that is adapted to supply a sufficient electrical bias to the electrode relative to the conductive region to cause the moveable component to deflect relative to the base such that the first contact surface interacts with a second contact surface; and

a first lubricant layer disposed on the process surface, wherein the lubricant layer includes a plurality of lubricant molecules preferentially bonded to the process surface and each lubricant molecule includes a lubricant portion that is adapted to reduce stiction-related forces between the first contact surface and the second contact surface.

15. The micromechanical device assembly of claim 14, wherein the base has a first side that includes the first contact surface and the process surface.

16. The micromechanical device assembly of claim 14, wherein the process surface comprises a portion of one of the one or more walls.

17. The micromechanical device assembly of claim 14, wherein the lubricant molecules that form the lubricant layer have a head group that is adapted to bond to the process surface, wherein the process surface comprises a material selected from a group consisting of silicon, silicon dioxide, titanium, aluminum and a glass material.

18. The micromechanical device assembly of claim 17, wherein the head group is selected from a group consisting of a oxysilane functional group, a trichlorosilane functional group and a carboxylate functional group.

19. The micromechanical device assembly of claim 14, wherein the lubricant molecules that form the lubricant layer have a head group that forms a weaker bond with the process surface and a stronger bond with the first or second contact surface.

20. The micromechanical device assembly of claim 14, further comprising a heating assembly that comprises:

a heating element that is in thermal communication with the process surface; and

a controller that is adapted to adjust the temperature of the process surface so that a portion of the lubricant layer disposed thereon can desorb into the processing region.

21. The micromechanical device assembly of claim 14, wherein one of the one or more walls is optically transparent and has a first side that contains the process surface.

22. The micromechanical device assembly of claim 14, further comprising a second lubricant layer disposed over the first contact surface or the second contact surface, wherein the second lubricant layer is a liquid lubricant layer that is adapted to reduce stiction-related forces between the first contact surface and the second contact surface.

23. The micromechanical device assembly of claim 14, wherein the first lubricant layer comprises:

a plurality of first lubricant molecules, wherein each first lubricant molecule has a first head group that is adapted to bond to the process surface and an end group; and

a plurality of second lubricant molecules, wherein each second lubricant molecule has a second head group that is adapted to bond to the end group.

24. The micromechanical device assembly of claim 23, wherein each of the plurality of first lubricant molecules are cross-linked with each adjacent first lubricant molecule.

25. The micromechanical device assembly of claim 23, wherein each of the plurality of second lubricant molecules are cross-linked with each adjacent second lubricant molecule.

26. A micromechanical device assembly, comprising:

a moveable component having a first contact surface;

a second contact surface, wherein the moveable component is coupled to the second contact surface, and the first contact surface interacts with the second contact surface during device operation;

an enclosure having one or more walls that form an operating region, wherein one of the one or more walls has a process surface that is disposed within the operating region; and

a first lubricant molecule disposed on the process surface, wherein the first lubricant molecule has a head group that is bonded to the process surface and the first lubricant molecule is adapted to desorb from the process surface at normal operating temperatures.

27. The micromechanical device assembly of claim 26, wherein the process surface is a material selected from a group consisting of silicon, silicon dioxide, a glass material and aluminum.

28. The micromechanical device assembly of claim 26, wherein the head group is selected from a group consisting of a oxysilane functional group, a trichlorosilane functional group and a carboxylate functional group.

29. The micromechanical device assembly of claim 26, wherein the normal operating temperature is between about 0°

C. and about 70°

C.

30. The micromechanical device assembly of claim 26, wherein the first lubricant molecules have a head group that forms a weaker bond with the process surface and a stronger bond with the first or second contact surface.

31. The micromechanical device assembly of claim 26, further comprising a heating assembly that comprises:

a heating element that is in thermal communication with the process surface; and

a controller that is adapted to adjust the temperature of the process surface so that a portion of the first lubricant molecules disposed thereon can desorb into the processing region.

32. The micromechanical device assembly of claim 26, wherein one of the one or more walls is optically transparent and has a first side that contains the process surface.

33. The micromechanical device assembly of claim 26, further comprising a second lubricant layer disposed over the first contact surface or the second contact surface, wherein the second lubricant layer is a liquid lubricant layer that is adapted to reduce stiction-related forces between the first contact surface and the second contact surface.

34. The micromechanical device assembly of claim 26, further comprising a second lubricant molecule that has a second head group that is adapted to bond to an end group that is attached to the first lubricant molecule.