US 12,113,510 B2 · Transversely-excited film bulk acoustic resonators with multiple piezoelectric membrane thicknesses on the same chip

Abstract

An acoustic resonator is fabricated with multiple piezoelectric plate thicknesses on a single chip. After conductor patterns are formed on a piezoelectric plate, the plate is bonded to a sacrificial substrate, with the conductor patterns facing the sacrificial substrate. The piezoelectric plate is then thinned to a desired thickness for shunt resonators. A mask is applied to the surface of the plate and selected areas of the piezoelectric plate are further thinned to a desired thickness for series resonators to form a thinned piezoelectric plate. A substrate with swimming pool cavities is bonded to the thinned piezoelectric plate, and the sacrificial substrate is removed.

Claims20

Dependent claims

A method for fabricating an acoustic filter with multiple piezoelectric plate thicknesses on a single chip, comprising:

forming conductor patterns on a piezoelectric plate;
bonding the piezoelectric plate to a sacrificial substrate, with the conductor patterns facing the sacrificial substrate;
thinning the piezoelectric plate to a first thickness for shunt resonators;
applying a mask and further thinning selected areas of the piezoelectric plate to a second thickness for series resonators to form a thinned piezoelectric plate;
bonding a substrate with a plurality of cavities to the thinned piezoelectric plate;
and
removing the sacrificial substrate.

4 more elements

A method for fabricating an acoustic resonator device on a single chip, the method comprising:

forming conductor patterns on a piezoelectric plate;
bonding the piezoelectric plate to a sacrificial substrate using an adhesive layer between the piezoelectric plate and the sacrificial substrate, with the conductor patterns facing the sacrificial substrate;
thinning the piezoelectric plate to a desired thickness for shunt resonators;
applying a mask and further thinning selected areas of the piezoelectric plate to another desired thickness for series resonators to form a thinned piezoelectric plate;
bonding a substrate of the single chip with swimming pool cavities to the further thinned piezoelectric plate;
removing the sacrificial substrate;
and
removing the adhesive layer.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application

17/339,841Filed 4 Jun 2021 · us provisional application

Priority

3 Feb 2021

Published

US 2022/0247373 A14 Aug 2022

Granted

8 Oct 2024

Term ends

Not estimatedThe source records don’t support an estimate.

Classification14 codes

H03H 9/54
Filters: comprising resonators of piezoelectric or electrostrictive material
H03H 3/02
For the manufacture of electromechanical resonators or networks: for the manufacture of piezoelectric or electrostrictive resonators or networks
H03H 9/02015
Of bulk acoustic wave devices: characteristics of piezoelectric layers, e.g. cutting angles
H03H 9/02157
Of bulk acoustic wave devices: dimensional parameters, e.g. ratio between two dimension parameters, length, width or thickness

Transversely-excited film bulk acoustic resonators with multiple piezoelectric membrane thicknesses on the same chip

Life of this patent

Transversely-excited film bulk acoustic resonators with multiple piezoelectric membrane thicknesses on the same chip

Life of this patent

Abstract

Claims20