Process of forming a micromechanical system containing an anti-stiction gas-phase lubricant

• US 20070115530A1
• Filed: 12/22/2005
• 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
• Granted Patent: US 7,471,439 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• 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 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 21/32 Micromanipulators structurally combined with microscopes
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B

Abstract

Embodiments of the present invention generally relate to a process of forming a device that has an improved usable lifetime due to the addition of a gas-phase lubricant that reduces the likelihood of stiction occurring between the various moving parts in an electromechanical device. One advantage of the disclosed device is that a gas-phase lubricant has a high diffusion rate and, therefore, is self-replenishing, meaning that it can quickly move back into a contact region after being physically displaced from the region by the contacting surfaces of the device during operation. Consequently, the gas-phase lubricant is more reliable than conventional solid or liquid lubricants in preventing stiction-related device failures.

Claims

1. A process for forming a micromechanical device assembly, the process comprising:

providing a lid assembly having one or more walls;

providing a base;

forming a micromechanical device that includes;

a moveable component having a first contact surface, wherein the first contact surface interacts with a second contact surface during device operation;

forming a processing region by bonding the lid assembly to the base;

positioning the micromechanical device in the processing region; and

providing a gas-phase lubricant within the processing region at a pressure greater than or equal to atmospheric pressure, wherein the gas-phase lubricant is adapted to reduce stiction-related forces between the first contact surface and the second contact surface.

2. The process of claim 1, wherein the moveable component comprises a mirror.

3. The process of claim 1, wherein the moveable component comprises a yoke that has a surface that is the first contacting surface.

4. The process of claim 1, wherein the base is a semiconductor substrate on which the moveable component is formed.

5. The process of claim 1, wherein the step of forming a processing region by bonding the lid assembly to the base is performed at a temperature less than about 250°

C.

6. The process of claim 1, wherein the gas-phase lubricant is adapted to reduce the stiction-related forces between the first contact surface and the second contact surface without performing an activation step, wherein the activation step requires heating the micromechanical device to a temperature greater than about 300°

C.

7. The process of claim 1, further comprising exposing a surface of the micromechanical device to electromagnetic radiation, wherein the electromagnetic radiation in adapted to modify the surface of the micromechanical device to facilitate the formation of a gas-phase lubricant monolayer on the surface.

8. A process for forming a micromechanical device assembly, the process comprising:

providing a packaging chamber having one or more walls that form a packaging chamber processing region;

forming a micromechanical device that includes;

a moveable component having a first contact surface, wherein the first contact surface interacts with a second contact surface during device operation;

positioning a lid assembly having one or more walls in the packaging chamber processing region;

positioning a base in the packaging chamber processing region;

positioning the formed micromechanical device in the packaging chamber processing region;

disposing a gas-phase lubricant within the packaging chamber processing region, wherein the gas-phase lubricant is adapted to reduce stiction-related forces between the first contact surface and the second contact surface; and

forming an operating region having the micromechanical device and the gas-phase lubricant positioned therein by bonding the lid assembly to the base.

9. The process of claim 8, further comprising the step of removing contaminants from the packaging chamber processing region by flowing a gas through the packaging chamber processing region.

10. The process of claim 9, wherein the gas contains argon (Ar), nitrogen (N2) or helium (He).

11. The process of claim 8, further comprising the step of removing contaminants from the packaging chamber processing region by evacuating the packaging chamber processing region to pressure below atmospheric pressure.

12. The process of claim 8, wherein the pressure of gas-phase lubricant disposed within the packaging chamber processing region is at a pressure between about about 700 Torr and about 800 Torr when the device processing region is formed.

13. A process for forming a plurality of micromechanical device assemblies, the process comprising:

providing a packaging chamber having one or more walls that form a packaging chamber processing region;

forming a plurality of micromechanical devices on a surface of a substrate, wherein the micromechanical devices include a moveable component having a first contact surface that interacts with a second contact surface during device operation;

positioning a lid assembly having a plurality of recesses formed therein in the packaging chamber processing region;

disposing a gas-phase lubricant within the packaging chamber processing region, wherein the gas-phase lubricant is adapted to reduce stiction-related forces between the first contact surface and the second contact surface;

bonding the lid assembly to the surface of the substrate so that a recess is positioned over each micromechanical device such that the gas-phase lubricant is disposed within a sealed operating region formed between the recess and the surface of the substrate; and

dicing the substrate to form a plurality of micromechanical device assemblies, wherein each micromechanical device assembly that contain a recess, a portion of the substrate and a micromechanical device positioned in the sealed operating region.

14. The process of claim 13, further comprising the step of removing contaminants from the packaging chamber processing region by flowing a gas through the packaging chamber processing region.

15. The process of claim 13, wherein the gas contains argon (Ar), nitrogen (N2) or helium (He).

16. The process of claim 13, further comprising the step of removing contaminants from the packaging chamber processing region by evacuating the packaging chamber processing region to pressure below atmospheric pressure.

17. The process of claim 13, wherein the pressure of gas-phase lubricant disposed within the packaging chamber processing region is at a pressure between about 700 Torr and about 800 Torr when the device processing region is formed.