Microelectromechanical systems (MEMS) resonators and related apparatus and methods

• US 9,030,080 B2
• Filed: 11/20/2012
• Issued: 05/12/2015
• Est. Priority Date: 04/29/2008
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Sand 9, Inc. (Analog Devices, Inc.)
• Inventors: Chen, David M., Kuypers, Jan H., Mohanty, Pritiraj, Schoepf, Klaus Juergen, Zolfagharkhani, Guiti, Goodelle, Jason, Rebel, Reimund
• Primary Examiner(s): DOUGHERTY, THOMAS M
• Application Number:
  US13/681,893
• Publication Number:
  US 20130140651A1
• Time in Patent Office: 903 Days
• Field of Search: 310/340, 310/344, 310/346, 310/348
• US Class Current: 310/346
• CPC Class Codes: B81B 3/0018 Structures acting upon the moving or flexible element for transforming energy into mechanical movement or vice versa, i.e. actuators, sensors, generators
• CPC Class Codes: H01L 2224/11 Manufacturing methods
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence
• CPC Class Codes: H03H 2009/241 Bulk-mode MEMS resonators
• 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: H10N 30/88 Mounts; Supports; Enclosures; Casings

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 capped microelectromechanical systems (MEMS) resonator, comprising:

a piezoelectric microelectromechanical systems (MEMS) resonating structure formed on a first wafer, the piezoelectric MEMS resonating structure comprising a resonating body including a piezoelectric material active layer and a layer of silicon; and

a cap wafer capping the piezoelectric MEMS resonating structure, wherein the cap wafer comprises no integrated circuitry,

wherein the cap wafer comprises an integrated heater.

2. The capped MEMS resonator of claim 1, wherein the cap wafer is formed of an insulating material, and wherein the capped MEMS resonator further comprises through-silicon vias (TSVs) in the cap wafer and configured to conduct electrical signals between the piezoelectric MEMS resonating structure and circuitry formed external to the capped MEMS resonator.

3. The capped MEMS resonator of claim 2, wherein the insulating material comprises glass.

4. The capped MEMS resonator of claim 2, wherein the insulating material comprises ceramic.

5. The capped MEMS resonator of claim 1, wherein the cap wafer is a silicon substrate.

6. The capped MEMS resonator of claim 5, wherein the silicon substrate is a thinned silicon substrate.

7. The capped MEMS resonator of claim 5, wherein the silicon substrate is an non-thinned silicon substrate.

9. The capped MEMS resonator of claim 1, wherein the cap wafer comprises no active circuitry.

10. The capped MEMS resonator of claim 1, wherein the cap wafer comprises an access hole formed therein.

11. The capped MEMS resonator of claim 1, coupled to an external circuit configured to control operation of the piezoelectric MEMS resonating structure.

12. The capped MEMS resonator of claim 11, wherein the cap wafer is formed of an insulating material, and wherein the capped MEMS resonator further comprises through-silicon vias (TSVs) in the cap wafer and configured to conduct electrical signals between the piezoelectric MEMS resonating structure and circuitry formed external to the capped MEMS resonator.

8. A capped microelectromechanical systems (MEMS) resonator, comprising:

a piezoelectric microelectromechanical systems (MEMS) resonating structure formed on a first wafer, the piezoelectric MEMS resonating structure comprising a resonating body including a piezoelectric material active layer and a layer of silicon; and

a cap wafer capping the piezoelectric MEMS resonating structure, wherein the cap wafer comprises no integrated circuitry,

wherein the cap wafer comprises an integrated thermistor.

13. The capped MEMS resonator of claim 8, wherein the cap wafer is formed of an insulating material, and wherein the capped MEMS resonator further comprises through-silicon vias (TSVs) in the cap wafer and configured to conduct electrical signals between the piezoelectric MEMS resonating structure and circuitry formed external to the capped MEMS resonator.

14. The capped MEMS resonator of claim 8, wherein the cap wafer is a silicon substrate.

15. The capped MEMS resonator of claim 8, wherein the cap wafer comprises an access hole formed therein.