US 8,522,411 B1Granted

Method to control BAW resonator top electrode edge during patterning

AssigneeTriQuint Semiconductor, Inc.

InventorsGuillaume Bouche, Ralph N. Wall

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Abstract

A method of fabricating a piezoelectric resonator includes providing a bottom electrode and a piezoelectric layer coupled to the bottom electrode. A bottom metal layer of a top electrode is deposited on the piezoelectric layer. A top metal layer of the top electrode is deposited on the bottom metal layer. A photoresist layer is deposited on the top metal layer. The photoresist layer is patterned and etched. The top metal layer is patterned and etched while the etched photoresist layer remains. The bottom metal layer is patterned and etched such that an entire perimeter side surface of the top metal layer is recessed relative to a perimeter edge of the bottom metal layer. The etched photoresist layer is removed. A passivation layer is deposited on the top and bottom metal layers such that the top and bottom metal layers are isolated from a subsequent metal etch step.

Claims16

Dependent claims

A method of fabricating a piezoelectric resonator, the method comprising:

a. providing a bottom electrode and a piezoelectric layer coupled to the bottom electrode;
b. depositing a bottom metal layer of a top electrode on the piezoelectric layer;
c. depositing a top metal layer of the top electrode on the bottom metal layer;
d. depositing a photoresist layer on the top metal layer;
e. patterning and etching the photoresist layer;
f. patterning and etching the top metal layer using the etched photoresist layer;
g. patterning and etching the bottom metal layer using the etched photoresist layer such that an entire perimeter side surface of the top metal layer is recessed relative to a perimeter edge of the bottom metal layer;
h. removing the etched photoresist layer;
and
l. depositing a passivation layer on the top metal layer and the bottom metal layer such that the top metal layer and the bottom metal layer are isolated from a subsequent metal etch step.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/564,723Filed 22 Sep 2009 · division
Priority: 16 Jan 2007
Granted: 3 Sep 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H03H 9/589
Means for mounting to a substrate, i.e. means constituting the material interface confining the waves to a volume: acoustic mirrors
H03H 9/131
For networks consisting of piezoelectric or electrostrictive materials: consisting of a multilayered structure
Y10T 29/42
Metal working: piezoelectric device making
Y10T 29/49156
Manufacturing circuit on or in base: with selective destruction of conductive paths