REDUCED STICTION AND MECHANICAL MEMORY IN MEMS DEVICES

• US 20100025832A1
• Filed: 07/31/2008
• Published: 02/04/2010
• Est. Priority Date: 07/31/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Atnip, Earl V., Jacobs, Simon Joshua
• Granted Patent: US 8,120,155 B2
• Time in Patent Office: Days
• US Class Current: 257/682
• CPC Class Codes: B81C 1/00285 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: H01L 21/54 Providing fillings in containers, e.g. gas fillings
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 23/26 including materials for absorbing or reacting with moisture or other undesired substances , e.g. getters
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]

Abstract

A MEMS device is packaged in a process which hydrogen (H) deuterium (D) for reduced stiction. H is exchanged with D by exposing the MEMS device with a deuterium source, such as deuterium gas or heavy water vapor, optionally with the assistance of a direct or downstream plasma.

Claims

1. A process for packaging a MEMS device, comprising the steps of:

placing the MEMS device in a package;

introducing a material including deuterium at levels beyond a naturally occurring level into the package;

sealing the package.

2. The process of claim 1 wherein the introducing step comprises the step of introducing water into the package wherein the water includes deuterium at levels beyond a naturally occurring level for water.

3. The process of claim 2 wherein the percentage of deuterium in the water is more than 1% of the hydrogen in the water.

4. The process of claim 3 wherein the percentage of deuterium in the water is more than 30% of the hydrogen in the water.

5. The process of claim 2 wherein the introducing step comprises the step of introducing heavy water into a getter.

6. The process of claim 5 wherein the step of introducing heavy water into the getter comprises the step of displacing solvent in the getter with heavy water.

7. The process of claim 5 wherein the step of introducing heavy water into the getter comprises the step of displacing non-heavy water in the getter with heavy water.

8. The process of claim 1 wherein the introducing step comprises the step of introducing a passivating source material including deuterium into the package.

9. The process of claim 8 wherein a passivating source material with normal levels of deuterium is introduced into the package in an ambient of heavy water vapor.

10. The process of claim 8 wherein the passivating material includes CH₃(CH₂)_nCOOD.

11. The process of claim 8 wherein the passivating material includes CD₃(CD₂)_nCOOH.

12. A packaged a MEMS device, comprising:

a MEMS device;

a sealed package surrounding the MEMS device;

a material including deuterium at levels beyond a naturally occurring level disposed in the package.

13. The packaged MEMS device of claim 12 wherein the material includes water with deuterium at levels beyond a naturally occurring level for water.

14. The packaged MEMS device of claim 13 wherein the percentage of deuterium in the water is more than 1% of the hydrogen in the water.

15. The packaged MEMS device of claim 14 wherein the percentage of deuterium in the water is more than 30% of the hydrogen in the water.

16. The packaged MEMS device of claim 13 wherein the material comprises a getter including heavy water.

17. The packaged MEMS device of claim 12 wherein the material is a passivating source material including deuterium.

18. The packaged MEMS device of claim 17 wherein the passivating material includes CH₃(CH₂)_nCOOD.

19. The packaged MEMS device of claim 17 wherein the passivating material includes CD₃(CD₂)_nCOOH.

20. The packaged MEMS device of claim 12 wherein the material is a compound with deuterium at a level of 30% or more of the hydrogen and hydrogen isotopes in the compound.

21. The packaged MEMS device of claim 12 wherein the material is a compound with deuterium at a level of 90% or more of the hydrogen and hydrogen isotopes in the compound.