Acoustic resonator with electrical interconnect disposed in underlying dielectric

Patent metadata

Field	Value
Publication number	US-9793874-B2
Application number	US-201414289568-A
Country	US
Kind code	B2
Filing date	May 28, 2014
Priority date	May 28, 2014
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

An apparatus comprises a substrate, a dielectric disposed on the semiconductor substrate, an acoustic resonator disposed on the dielectric, and an electrical interconnect disposed in the dielectric and configured to transmit an electrical signal to or from at least one electrode of the acoustic resonator through a signal path disposed at least partially below a level of the acoustic resonator.

First claim

The invention claimed is:

1. An apparatus, comprising:
a substrate;
a dielectric disposed on the substrate;
an acoustic resonator disposed on the dielectric, and disposed on a pedestal structure within an air cavity in the dielectric; and
an electrical interconnect disposed in the dielectric and configured to transmit an electrical signal to or from at least one electrode of the acoustic resonator through a signal path disposed at least partially below a level of the acoustic resonator, wherein the acoustic resonator has an opening at its center, and a top electrode of the acoustic resonator is connected to the electrical interconnect through the opening.

2. The apparatus of claim 1 , wherein the acoustic resonator is a film bulk acoustic resonator (FBAR).

3. The apparatus of claim 1 , wherein the substrate is an electrical insulator.

4. The apparatus of claim 1 , wherein the electrical interconnect connects an electrode of the acoustic resonator to an electrode of another acoustic resonator disposed on the dielectric.

5. The apparatus of claim 4 , wherein the acoustic resonator and the other acoustic resonator are part of a filter comprising multiple acoustic resonators disposed on the dielectric.

6. The apparatus of claim 2 , further comprising a layer of silicon carbide disposed between the dielectric and the air cavity.

7. The apparatus of claim 1 , wherein the dielectric comprises silicon dioxide.

8. The apparatus of claim 1 , wherein the electrical interconnect comprises a plurality of metal layers and vias stacked within the dielectric.

9. The apparatus of claim 1 , wherein the electrical interconnect is connected to the acoustic resonator through the pedestal structure.

10. The apparatus of claim 1 , further comprising a microcap disposed on the dielectric over the acoustic resonator.

11. The apparatus of claim 1 , further comprising at least one backside via penetrating the substrate and providing an electrical connection between at least one electrode of the acoustic resonator and at least one backside pad on the substrate.

12. The apparatus of claim 1 , wherein the acoustic resonator comprises a piezoelectric layer comprising scandium-doped aluminum oxide (ASN).

Assignees

• Avago Technologies General Ip
• Avago Tech General Ip Singapore (Singapore) Pte Ltd

Inventors

• Small Martha K

Classifications

• H03H9/174

  Membranes · CPC title

• H03H9/205

  having multiple resonators (crystal tuning forks H03H9/21) · CPC title

• H03H9/0561

  consisting of a multilayered structure · CPC title

• H03H9/1007 Primary

  for bulk acoustic wave [BAW] devices · CPC title

• Y10T29/43

  Electric condenser making · CPC title