Method of manufacturing vertically separated acoustic filters and resonators
AssigneeAvago Technologies General IP (Singapore) Pte. Ltd.
InventorsRichard C. Ruby, John D. Larson, III
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Abstract
An apparatus including vertically separated acoustic resonators are disclosed. The apparatus includes a first acoustic resonator on a substrate and a second acoustic resonator vertically separated above the first acoustic resonator. Because the resonators are vertically separated above another, total area required to implement the resonators is reduced thereby savings in die size and cost are realized. The vertically separated resonators are supported by standoffs that are fabricated on the substrate, or on a resonator.
Claims4
A method of fabricating an apparatus, the method comprising:
- fabricating a first resonator on a substrate, said first resonator comprising a bottom electrode and a top electrode sandwiching a piezoelectric layer;
- fabricating a sacrificial layer surrounding said first resonator;
- fabricating a second resonator on said sacrificial layer above said standoffs and above said first acoustic resonator, said second resonator comprising a bottom electrode and a top electrode sandwiching another piezoelectric layer, wherein said second acoustic resonator is vertically separated from said first acoustic resonator such that little or no acoustic energy is coupled between said first acoustic resonator and said second acoustic resonator;
- fabricating a standoff between said top electrode of said first acoustic resonator and said bottom electrode of said second acoustic resonator, wherein said top electrode of said first acoustic resonator and said bottom electrode of said second acoustic resonator are electrically connected by said standoff;
- and
- and removing said sacrificial layer.
A method of fabricating an apparatus, the method comprising:
- fabricating a first resonator on a substrate, said first resonator comprising a first bottom electrode and a first top electrode sandwiching a first piezoelectric layer;
- fabricating a sacrificial layer surrounding said first resonator;
- fabricating standoffs;
- fabricating a second resonator on said sacrificial layer above said standoffs, said second resonator comprising a second bottom electrode and a second top electrode sandwiching a second piezoelectric layer, wherein said second resonator is fabricated above said first resonator, and said second resonator is vertically separated from said first resonator such that little or no acoustic energy is coupled between said first resonator and second acoustic resonator;
- and
- removing said sacrificial layer, wherein said first top electrode and said second bottom electrode are at different electrical potentials relative to each other thereby creating a capacitive potential between said first top electrode and said second bottom electrode of said second.
A method of fabricating an apparatus, the method comprising:
- fabricating a first resonator on a substrate;
- fabricating a sacrificial layer surrounding said first resonator;
- fabricating standoffs;
- fabricating a second resonator on said sacrificial layer above said standoffs, said second resonator being fabricated above said first resonator, and said second resonator being vertically separated from said first resonator such that little or no acoustic energy is coupled between said first resonator and said second resonator;
- and
- removing said sacrificial layer, wherein said standoffs separate said first acoustic resonator from said second acoustic resonator;
- and wherein said standoffs comprise tungsten.
Dependencies are inferred from the claim text.