Granted Patent B1

US 8,350,445 · App. 13/168,101 · Granted Jan 8, 2013

Assignee: Avago Technologies Wireless IP (Singapore) Pte. Ltd.

Abstract

Claims (16)

1. A bulk acoustic wave (BAW) resonator, comprising:

a first electrode formed on a substrate;

a piezoelectric layer formed on the first electrode;

a second electrode formed on the first piezoelectric layer;

a non-piezoelectric layer formed on the first electrode and adjacent to the piezoelectric layer; and

a bridge formed between the non-piezoelectric layer and the first or second electrode.

2. The BAW resonator of claim 1 , wherein the bridge is an air-bridge.

3. The RAW resonator of claim 1 , wherein the bridge comprises a cavity Idled with a dielectric material or a metal.

4. The BAW resonator of claim 1 , wherein the non-piezoelectric layer is polycrystalline.

5. The BAW resonator of claim 1 , wherein the piezoelectric layer comprises a material, and the non-piezoelectric layer is a non-crystalline form of the material.

6. The RAW resonator of claim 5 , wherein the material is aluminum nitride.

7. The RAW resonator of claim 1 , further comprising an acoustic reflector disposed beneath the first electrode.

8. The BAW resonator of claim 7 , wherein the acoustic reflector comprises a cavity, and the bridge overlaps the cavity in a lateral direction of the BAW resonator.

9. The BAW resonator of claim 1 , wherein the piezoelectric layer has a piezoelectric coupling coefficient (e33) and the non-piezoelectric layer has a piezoelectric coupling coefficient that is less or equal to 80% of the first piezoelectric coupling coefficient.

10. The BAW resonator of claim 1 , wherein the bridge is formed on multiple sides of a BAW resonator structure formed in an apodized pentagon shape.

11. The BAW resonator of claim 1 , wherein the bridge has a trapezoidal shape.

Assignments (8)

Continuity (1)