MEMS DEVICE WITH CONDUCTIVE PATH THROUGH SUBSTRATE

• US 20050127499A1
• Filed: 04/19/2004
• Published: 06/16/2005
• Est. Priority Date: 12/15/2003
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Nunan, Thomas Kieran, Harney, Kieran P., Felton, Lawrence E., Alie, Susan A., Wachtmann, Bruce
• Granted Patent: US 6,936,918 B2
• Time in Patent Office: Days
• US Class Current: 257/704
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81C 2203/019 characterised by the material or arrangement of seals between parts
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

A MEMS device has at least one conductive path extending from the top facing side of its substrate (having MEMS structure) to the bottom side of the noted substrate. The at least one conductive path extends through the substrate as noted to electrically connect the bottom facing side with the MEMS structure.

Claims

1. A MEMS device comprising:

a substrate having a top facing side and a bottom facing side, the top facing side including MEMS structure; and

at least one conductive path extending through the substrate from the MEMS structure to the bottom facing side, the at least one conductive path being integral with and formed from substantially the same material as the MEMS structure.

2. The MEMS device as defined by claim 1 further including a cap about at least a portion of the MEMS structure.

3. The MEMS device as defined by claim 2 wherein the cap and substrate form a cavity that at least in part contains the MEMS structure.

4. The MEMS device as defined by claim 1 wherein the at least one conductive path is substantially flush with or extends outwardly from the bottom facing side of the substrate.

5. The MEMS device as defined by claim 1 further including at least one of a plated bump, deposited bond pad, and a solder ball secured to the at least one conductive path.

6. The MEMS device as defined by claim 1 wherein the conductive path includes polysilicon.

7. The MEMS device as defined by claim 1 wherein the MEMS structure includes a movable mass.

8. The MEMS device as defined by claim 1 further including circuitry supported by the substrate, the circuitry being in electrical communication with the at least one conductive path, the substrate including silicon germanium.

9. The MEMS device as defined by claim 1 wherein the at least one conductive path formed from a silicon-based material.

10. A MEMS device comprising:

a substrate having a top facing side and a bottom facing side, the top facing side including MEMS structure; and

means for conducting electrical signals between the MEMS structure and the bottom facing side, the conducting means extending through the substrate from the MEMS structure to the bottom facing side, the conducting means being integral with the MEMS structure.

11. The MEMS device as defined by claim 10 wherein the conducting means includes doped polysilicon.

12. The MEMS device as defined by claim 10 further including means for containing at least a portion of the MEMS structure.

13. The MEMS device as defined by claim 10 further including at least one of a plated bump, deposited bond pad, and a solder ball secured to the conducting means at the bottom facing surface.

14. The MEMS device as defined by claim 10 wherein the conducting means is substantially flush with or extends outwardly from the bottom facing side of the substrate.

15. The MEMS device as defined by claim 10 wherein the MEMS structure includes means for detecting motion of the substrate.

16. A MEMS system comprising:

a first substrate having circuitry and an interface port to the circuitry;

a MEMS device having a second substrate with a top facing side and a bottom facing side, the top facing side including MEMS structure, the MEMS device also having a conductive path extending through the second substrate from the MEMS structure to the bottom facing side, the conductive path being integral with the MEMS structure;

the conductive path being coupled with the interface port on the first substrate to electrically communicate the circuitry with the MEMS structure.

17. The MEMS system as defined by claim 16 wherein the MEMS device is free of circuitry.

18. The MEMS device as defined by claim 16 further including a cap secured to the second substrate, the cap containing at least a portion of the MEMS structure.

19. The MEMS device as defined by claim 16 wherein the conductive path and a MEMS structure are formed from the same material.

20. The MEMS device as defined by claim 16 wherein the MEMS structure includes a movable mass.

21. The MEMS device as defined by claim 16 further including an insulator positioned between the conductive path and at least a part of the second substrate.

22. The MEMS system as defined by claim 16 wherein the MEMS structure defines a plan boundary on the second substrate, the conductive path being within the plan boundary.

23. The MEMS system as defined by claim 16 wherein the MEMS device includes circuitry.