Integration of piezoelectric materials with substrates

• US 9,048,811 B2
• Filed: 05/01/2013
• Issued: 06/02/2015
• Est. Priority Date: 03/31/2009
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Sand 9, Inc. (Analog Devices, Inc.)
• Inventors: Chen, David M., Kuypers, Jan H., Gaidarzhy, Alexei, Zolfagharkhani, Guiti, Goodelle, Jason
• Primary Examiner(s): DOUGHERTY, THOMAS M
• Application Number:
  US13/874,752
• Publication Number:
  US 20130313947A1
• Time in Patent Office: 762 Days
• Field of Search: 310/340, 310/344, 310/348
• US Class Current: 1/1
• 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: H03H 9/1057 for microelectro-mechanical devices

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 seal ring formed of an electrically conductive material disposed between the substrate and the cap such that the substrate and the cap are sealed together by the seal ring and have a sealed, enclosed volume therebetween;

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

a conductive path distinct from the seal ring and electrically connecting the micromechanical resonator to the integrated circuitry, wherein at least a portion of the conductive path is formed of the electrically conductive material.

2. The packaged micromechanical resonator of claim 1, wherein the conductive path comprises a pillar.

3. The packaged micromechanical resonator of claim 2, wherein the pillar is formed of the electrically conductive material.

4. The packaged micromechanical resonator of claim 1, wherein the conductive path runs at least partly through the sealed, enclosed volume.

5. The packaged micromechanical resonator of claim 1, wherein the seal ring defines a perimeter, and wherein at least part of the conductive path is disposed within the perimeter.

6. The packaged micromechanical resonator of claim 5, wherein the conductive path is disposed entirely within the perimeter.

7. The packaged micromechanical resonator of claim 1, wherein the conductive path has a thickness between the substrate and the cap and wherein the conductive path has a variable width along the thickness.

8. The packaged micromechanical resonator of claim 1, wherein the seal ring and the conductive path are disposed in a side-by-side configuration.

9. The packaged micromechanical resonator of claim 1, wherein the electrically conductive material comprises metal.

10. The packaged micromechanical resonator of claim 1, wherein the seal ring defines a perimeter, wherein the conductive path comprises a pillar formed of the electrically conductive material and disposed within the perimeter, and wherein the micromechanical resonator is suspended within the sealed, enclosed volume.

11. An apparatus, comprising:

a substrate;

a cap comprising an integrated circuit;

an electrically conductive seal ring formed of an electrically conductive material and configured to seal the substrate and the cap to each other to at least partially define a sealed volume between the substrate and the cap;

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

a conductive path distinct from the seal ring and electrically connecting the integrated circuit to the micromechanical resonator, wherein at least a portion of the conductive path is formed of the electrically conductive material.

12. The apparatus of claim 11, wherein the conductive path comprises a pillar.

13. The apparatus of claim 12, wherein the pillar is formed of the electrically conductive material.

14. The apparatus of claim 11, wherein the conductive path runs at least partly through the sealed volume.

15. The apparatus of claim 11, wherein the seal ring defines a perimeter, and wherein at least part of the conductive path is disposed within the perimeter.

16. The apparatus of claim 11, wherein the conductive path has a thickness between the substrate and the cap and wherein the conductive path has a variable width along the thickness.

17. The apparatus of claim 11, wherein the seal ring and the conductive path are disposed in a side-by-side configuration.

18. The apparatus of claim 11, wherein the electrically conductive material comprises metal.

19. The apparatus of claim 11, wherein the sealed volume is a vacuum.

20. The apparatus of claim 11, wherein the micromechanical resonator is suspended within the sealed volume.