INTEGRATION OF PIEZOELECTRIC MATERIALS WITH SUBSTRATES

• US 20110187227A1
• Filed: 10/06/2010
• Published: 08/04/2011
• Est. Priority Date: 03/31/2009
• Status: Active Grant

• Current Assignee: Sand9, Inc.
• Original Assignee: Sand9, Inc.
• Inventors: Kuypers, Jan H., Goodelle, Jason, Chen, David M., Zolfagharkhani, Guiti, Gaidarzhy, Alexei
• Granted Patent: US 8,466,606 B2
• Time in Patent Office: Days
• US Class Current: 310/318
• CPC Class Codes: H03H 3/007 for the manufacture of electromechanical resonators or networks
• CPC Class Codes: H03H 9/02007 of bulk acoustic wave devices
• CPC Class Codes: H03H 9/02244 of microelectro-mechanical resonators
• CPC Class Codes: H03H 9/02535 of surface acoustic wave devices
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

Devices having piezoelectric material structures integrated with substrates are described. Fabrication techniques for forming such devices are also described. The fabrication may include bonding a piezoelectric material wafer to a substrate of a differing material. A structure, such as a resonator, may then be formed from the piezoelectric material wafer.

Claims

1. A packaged micromechanical resonator, comprising:

a substrate;

a cap comprising integrated circuitry;

a first portion of an electrically conductive material between the substrate and the cap, disposed such that the substrate, the cap, and the first portion of the electrically conductive material define a sealed, enclosed volume;

a micromechanical resonator comprising a piezoelectric material disposed within the enclosed volume; and

a second portion of the electrically conductive material between the substrate and the cap constructed and arranged such that a signal can be transmitted between the micromechanical resonator and the integrated circuitry through the second portion of the electrically conductive material.

5. A resonator as in claim 1, wherein the resonator comprises a microelectromechanical systems (MEMS) resonator.

6. A resonator as in claim 1, wherein the resonator is configured to support Lamb waves.

7. A resonator as in claim 1, wherein the resonator comprises a piezoelectric material.

8. A resonator as in claim 1, wherein the resonator comprises a piezoelectric material chosen from the group consisting of:

aluminum nitride (AlN), zinc oxide (ZnO), cadmium sulfide (CdS), lead titanate (PbTiO₃), lead zirconate titanate (PZT), lithium niobate (LiNbO₃), lithium tantalate (LiTaO₃), potassium niobate (KNbO₃), Li₂B₄O₇, langasite (La₃Ga₅SiO₁₄), gallium arsenside (GaAs), barium sodium niobate, bismuth germanium oxide, indium arsenide, and indium antimonide.

9. A resonator as in claim 1, wherein the resonator is suspended above the substrate.

10. A resonator as in claim 1, wherein the substrate has a cavity formed therein, and wherein the resonator is suspended above the cavity.

11. A resonator as in claim 1, wherein the first and/or second portions of electrically conductive material comprise an electrically conductive polymer and/or a metal.

12. A resonator as in claim 1, wherein the first and/or second portions of electrically conductive material comprise gold, silver, copper, and/or tin.

13. A resonator as in claim 1, wherein the integrated circuitry is constructed and arranged to control the resonator.

14. A resonator as in claim 1, wherein the integrated circuitry is constructed and arranged to actuate the resonator and/or detect vibration of the resonator.

15. A resonator as in claim 1, wherein the first portion of the electrically conductive material circumscribes the resonator.

16. A resonator as in claim 1, wherein the first and/or second portions of the electrically conductive material have a resistivity of less than about 1000 Ω

m.

17. A resonator as in claim 1, wherein the packaged resonator comprises a hermetic seal.

19. A resonator as in claim 1, wherein the first and/or second portions of the electrically conductive material has a thermal conductivity of at least about 5 W/mK.

20. A resonator as in claim 1, wherein the second portion of the electrically conductive material is used as part of a ground electrical connection.

21. A resonator as in claim 1, wherein the first and/or second portions of the electrically conductive material are printed, sputtered, or evaporated onto the substrate and/or cap.

22. A resonator as in claim 1, wherein the substrate and/or cap comprises at least a portion of a semiconductor wafer.

23. A resonator as in claim 1, wherein the first and/or second portions of the electrically conductive material have an average thickness of between about 0.1 microns and about 100 microns.

24. A resonator as in claim 1, wherein the first and second portions of the electrically conductive material are the same portion of the electrically conductive material.

25. A resonator as in claim 1, wherein the first and second portions of the electrically conductive material are different portions of the electrically conductive material.

26. A resonator as in claim 1, wherein the first and second portions of the electrically conductive material have the same chemical composition.

27. A resonator as in claim 1, wherein the first and second portions of the electrically conductive material have different chemical compositions.

2. A packaged micromechanical resonator, comprising:

a substrate;

a cap comprising integrated circuitry;

a first portion of an electrically conductive material between the substrate and the cap, disposed such that the substrate, the cap, and the first portion of the electrically conductive material define a sealed, enclosed volume;

a micromechanical resonator disposed within the enclosed volume; and

a second portion of the electrically conductive material between the substrate and the cap constructed and arranged such that a signal can be transmitted between the micromechanical resonator and the integrated circuitry through the second portion of the electrically conductive material;

wherein the first and/or second portions of the electrically conductive material have an average thickness of at least about 5 microns.

3. A packaged micromechanical resonator, comprising:

a substrate;

a cap comprising integrated circuitry;

a first portion of an electrically conductive material between the substrate and the cap, disposed such that the substrate, the cap, and the first portion of the electrically conductive material define a sealed, enclosed volume;

a micromechanical resonator configured to oscillate in plane disposed within the enclosed volume; and

a second portion of the electrically conductive material between the substrate and the cap constructed and arranged such that a signal can be transmitted between the micromechanical resonator and the integrated circuitry through the second portion of the electrically conductive material.

4. A method of packaging a micromechanical resonator, comprising:

providing a substrate on which a micromechanical resonator is disposed;

providing a cap comprising integrated circuitry;

positioning first and second portions of an electrically conductive material between the substrate and the cap; and

modifying the first and second portions of the electrically conductive material such that the first portion of the electrically conductive material produces a seal between the substrate and the cap and such that a signal can be transmitted between the micromechanical resonator and the integrated circuitry through the second portion of the electrically conductive material.

18. A resonator as in claim 4, wherein modifying the first and/or second portions of the electrically conductive material comprises heating the first and/or second portions of the electrically conductive material.