Transversely-excited film bulk acoustic resonator with lateral etch stop
AssigneeResonant Inc.
InventorsPatrick Turner, Carolyn Bianco, Charles Chung
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Abstract
Acoustic resonator devices and methods are disclosed. An acoustic resonator device includes a substrate having a front surface and a cavity, a perimeter of the cavity defined by a lateral etch-stop comprising etch-stop material. A back surface of a single-crystal piezoelectric plate is attached to the front surface of the substrate except for a portion of the piezoelectric plate that forms a diaphragm that spans the cavity. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm.
Claims18
An acoustic resonator device comprising:
- a substrate comprising a device layer having opposed front and back surfaces, a handle layer, and a buried layer laminated between the handle layer and the back surface of the device layer, wherein a cavity open to the front surface is formed in the device layer;
- a lateral etch-stop that defines a perimeter of the cavity, the lateral etch-stop comprising a lateral etch-stop material different from a material of the device layer;
- a single-crystal piezoelectric plate having opposed front and back surfaces, the back surface attached to the front surface of the device layer except for a portion of the piezoelectric plate forming a diaphragm that spans the cavity;
- and
- an interdigital transducer (IDT) formed on the front surface of the piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm.
An acoustic filter device comprising:
- a substrate comprising a device layer having opposed front and back surfaces, a handle layer, and a buried layer laminated between the handle layer and the back surface of the device layer, wherein a plurality of cavities open to the front surface are formed in the device layer;
- a plurality of lateral etch-stops, each lateral etch-stop defining a perimeter of a respective cavity from the plurality of cavities, each lateral etch-stop comprising a lateral etch-stop material different from a material of the device layer;
- a single-crystal piezoelectric plate having opposed front and back surfaces, the back surface attached to the front surface of the substrate except for portions of the piezoelectric plate forming a plurality of diaphragms, each diaphragm spanning a respective cavity from the plurality of cavities;
- and
- a plurality of interdigital transducers (IDTs) of a plurality of resonators formed on the front surface of the piezoelectric plate such that interleaved fingers of each IDT are disposed on a respective diaphragm from the plurality of diaphragms.
Dependencies are inferred from the claim text.