Method of mass loading of thin film bulk acoustic resonators (FBAR) for creating resonators of different frequencies and apparatus embodying the method
AssigneeAgilent Technologies, Inc.
InventorsRichard C. Ruby, Paul D. Bradley, John D. Larson, III
Life of this patent
Estimating the term…
Abstract
A method for fabricating a resonator, and in particular, a thin film bulk acoustic resonator (FBAR), and a resonator embodying the method are disclosed. An FBAR is fabricated on a substrate by introducing a mass loading electrode to a bottom electrode layer. For a substrate having multiple resonators, mass loading bottom electrode is introduced for only selected resonator to provide resonators having different resonance frequencies on the same substrate.
Claims21
A method of fabricating resonators on a substrate, the method comprising:
- fabricating a bottom loading electrode;
- fabricating a first bottom core electrode and a second bottom core electrode, the first bottom core electrode completely bridging a cavity and fabricated over the bottom loading electrode that also completely bridges the cavity, the first bottom core electrode together with the bottom loading electrode defining a first bottom electrode, and the second bottom core electrode defining a second bottom electrode;
- fabricating a piezoelectric (PZ) layer;
- fabricating a first top electrode such that a first portion of the PZ layer is sandwiched between the first top electrode on one side and the first bottom electrode on the other side, forming a first resonator;
- and
- fabricating a second top electrode such that a second portion of the PZ layer is sandwiched between the second top electrode on one side and the second bottom electrode on the other side, forming a second resonator.
A method of fabricating a resonator on a substrate, the method comprising:
- fabricating a bottom loading electrode that completely bridges a cavity;
- fabricating a bottom core electrode above the bottom loading electrode, the bottom core electrode also completely bridging the cavity;
- fabricating a piezoelectric (PZ) layer;
- and
- fabricating a top electrode above the PZ layer.
A resonator comprising a bottom a top electrode sandwiching a piezoelectric (PZ) layer, the bottom electrode including a bottom loading electrode that completely bridges a cavity and a bottom core electrode portion that also completely bridges the cavity.
An apparatus comprising:
- a first resonator comprising a first bottom and a first top electrode sandwiching a first piezoelectric (PZ) material, the first bottom electrode including a bottom loading electrode that completely bridges a cavity and a bottom core electrode that also completely bridges a cavity;
- and
- a second resonator comprising a second bottom and a second top electrode sandwiching a second PZ material.
Dependencies are inferred from the claim text.