Lithographically-defined multi-standard multi-frequency high-Q tunable micromechanical resonators

• US 7,639,105 B2
• Filed: 01/18/2008
• Issued: 12/29/2009
• Est. Priority Date: 01/19/2007
• Status: Expired due to Fees

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Ho, Gavin Kar-Fal, Abdolvand, Reza, Ayazi, Farrokh
• Primary Examiner(s): Takaoka; Dean O
• Application Number:
  US12/009,527
• Publication Number:
  US 20080246559A1
• Time in Patent Office: 711 Days
• Field of Search: 333/186, 333/187, 333/189, 333/191, 333/197
• US Class Current: 333/186
• CPC Class Codes: H03H 2003/027 the resonators or networks being of the microelectro-mechanical [MEMS] type
• CPC Class Codes: H03H 2009/02196 operating on the FBAR element, e.g. by direct application of a tuning DC voltage
• CPC Class Codes: H03H 2009/02496 Horizontal, i.e. parallel to the substrate plane
• CPC Class Codes: H03H 2009/241 Bulk-mode MEMS resonators
• CPC Class Codes: H03H 9/172 Means for mounting on a substrate, i.e. means constituting the material interface confining the waves to a volume
• CPC Class Codes: H03H 9/2405 of microelectro-mechanical resonators

Abstract

Disclosed are micromechanical resonator apparatus having features that permit multiple resonators on the same substrate to operate at different operating frequencies. Exemplary micromechanical resonator apparatus includes a support substrate and suspended micromechanical resonator apparatus having a resonance frequency. In one embodiment, the suspended micromechanical resonator apparatus comprises a device substrate that is suspended from and attached to the support substrate, a piezoelectric layer formed on the suspended device substrate, and a plurality of interdigitated upper electrodes formed on the piezoelectric layer. In another embodiment, the suspended micromechanical resonator apparatus comprises a device substrate that is suspended from and attached to the support substrate, a lower electrode formed on the suspended device substrate, a piezoelectric layer formed on the lower electrode, and a plurality of interdigitated upper electrodes formed on the piezoelectric layer. The substrate may comprise a silicon substrate, or a semiconductor-on-insulator substrate, such as a diamond on silicon substrate. Additionally, lateral frequency-adjusting electrodes may be disposed adjacent to the resonator apparatus that are separated therefrom by a capacitive gap, and which are configured to receive a direct current voltage that adjusts the resonance frequency of the resonator apparatus.

Claims

1. A composite micromechanical resonator apparatus, comprising:

a support substrate; and

a suspended micromechanical resonator apparatus having a resonance frequency comprising;

a suspended device substrate that is suspended from and attached to the support substrate;

at least one lower electrode on the suspended device substrate;

a piezoelectric layer on the lower electrode; and

at least one upper electrode with a plurality of periodic regions on the piezoelectric layer.

2. The apparatus recited in claim 1 wherein the device substrate comprises single crystal silicon.

3. The apparatus recited in claim 1 wherein the device substrate comprises semiconductor material.

4. The apparatus recited in claim 1 wherein the device substrate comprises a material selected from a group including diamond, nanocrystalline diamond, silicon carbide, silicon-germanium, and gallium arsenide.

5. The apparatus recited in claim 1 wherein the device substrate comprises silicon dioxide.

6. The apparatus recited in claim 1 wherein the device substrate comprises silicon dioxide and single crystal silicon.

7. The apparatus recited in claim 1 wherein the device substrate comprises silicon dioxide and diamond.

8. The apparatus recited in claim 1 wherein the resonator apparatus is connected to the device substrate through a plurality of anchors.

9. The apparatus recited in claim 1 wherein the at least one upper electrode has one or more interdigitated regions.

10. The apparatus recited in claim 1 wherein the support substrate comprises a semiconductor-on-insulator substrate.

11. A composite micromechanical resonator apparatus, comprising:

a support substrate; and

a suspended micromechanical resonator apparatus having a resonance frequency comprising;

a suspended device substrate that is suspended from and attached to the support substrate;

a piezoelectric layer above the device substrate; and

at least one upper electrode with a plurality of periodic regions on the piezoelectric layer.

12. The apparatus recited in claim 11 wherein the device substrate comprises single crystal silicon.

13. The apparatus recited in claim 11 wherein the device substrate comprises semiconductor material.

14. The apparatus recited in claim 11 wherein the device substrate comprises a material selected from a group including diamond, nanocrystalline diamond, silicon carbide, silicon-germanium, gallium arsenide and metal.

15. The apparatus recited in claim 11 wherein the device substrate comprises a composite substrate comprising silicon dioxide.

16. The apparatus recited in claim 11 wherein the device substrate comprises silicon dioxide and single crystal silicon.

17. The apparatus recited in claim 11 wherein the device substrate comprises silicon dioxide and diamond.

18. The apparatus recited in claim 11 wherein the resonator apparatus is connected to the device substrate through a plurality of anchors.

19. The apparatus recited in claim 11 wherein the at least one upper electrode has one or more interdigitated regions.

20. The apparatus recited in claim 11 wherein the support substrate comprises a semiconductor-on-insulator substrate.