Back to results
US 11,146,231 B2Granted
Solidly-mounted transversely-excited film bulk acoustic resonator with recessed interdigital transducer fingers
AssigneeResonant Inc.
InventorViktor Plesski
Life of this patent
Estimating the term…
Abstract
Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate, a piezoelectric plate having front and back surfaces, and an acoustic Bragg reflector between a surface of the substrate and the back surface of the piezoelectric plate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate. The IDT is configured to excite a shear primary acoustic mode in the piezoelectric plate in response to a radio frequency signal applied to the IDT. At least one finger of the IDT is disposed in a groove in the piezoelectric plate.
Claims36
An acoustic resonator device comprising:
- a substrate having a surface;
- a piezoelectric plate having front and back surfaces;
- an acoustic Bragg reflector between the surface of the substrate and the back surface of the piezoelectric plate;
- and
- an interdigital transducer (IDT) formed on the front surface of the piezoelectric plate, the IDT and the piezoelectric plate configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic mode in the piezoelectric plate, wherein at least one finger of the IDT is disposed in a groove in the piezoelectric plate, and wherein a depth of the groove is less than or equal to a thickness of the piezoelectric plate.
2 more elements
A filter device, comprising:
- a substrate;
- a piezoelectric plate having front and back surfaces;
- an acoustic Bragg reflector between the surface of the substrate and the back surf ace of the piezoelectric plate;
- and
- a conductor pattern formed on the front surface, the conductor pattern including a plurality of interdigital transducers (IDTs) of a respective plurality of acoustic resonators, interleaved fingers of each of the plurality of IDTs disposed on the piezoelectric plate, wherein each of the IDTs are configured to excite respective shear primary acoustic modes in the piezoelectric plate in response to respective radio frequency signals applied to each IDT, wherein at least one finger of at least one of the plurality of IDTs is disposed in a groove in the piezoelectric plate, and wherein a depth of the groove is less than or equal to a thickness of the piezoelectric plate.
2 more elements
A method of fabricating an acoustic resonator device, comprising:
- forming an acoustic Bragg reflector by depositing material layers on one or both of a surface of a device substrate and a back surface of a piezoelectric plate having a front surface attached to a sacrificial substrate;
- bonding the piezoelectric plate to the device substrate such that layers of the acoustic Bragg reflector are between the back surface of the piezoelectric plate and the surface of the device substrate;
- removing the sacrificial substrate to expose the front surface of the piezoelectric plate;
- and
- forming an interdigital transducer (IDT) on the front surface of the piezoelectric plate such that interleaved fingers of the IDT are configured to excite a shear primary acoustic mode in the piezoelectric plate in response to a radio frequency signal applied to the IDT, wherein at least one finger of the IDT is disposed in a groove in the piezoelectric plate.
2 more elements
An acoustic resonator device comprising:
- a substrate having a surface;
- a piezoelectric plate having front and back surfaces;
- an acoustic Bragg reflector between the surface of the substrate and the back surface of the piezoelectric plate;
- and
- an interdigital transducer (IDT) formed on the front surface of the piezoelectric plate, the IDT and the piezoelectric plate configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic mode in the piezoelectric plate, wherein at least one finger of the IDT is disposed in a groove in the piezoelectric plate, and wherein a depth of the groove is less than or equal to a thickness of the at least one finger.
2 more elements
An acoustic resonator device comprising:
- a substrate having a surface;
- a piezoelectric plate having front and back surfaces;
- an acoustic Bragg reflector between the surface of the substrate and the back surface of the piezoelectric plate;
- and
- an interdigital transducer (IDT) formed on the front surface of the piezoelectric plate, the IDT and the piezoelectric plate configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic mode in the piezoelectric plate, wherein at least one finger of the IDT is disposed in a groove in the piezoelectric plate, and wherein the piezoelectric plate is a rotated z-cut lithium niobate plate.
2 more elements
A filter device, comprising:
- a substrate;
- a piezoelectric plate having front and back surfaces;
- an acoustic Bragg reflector between the surface of the substrate and the back surface of the piezoelectric plate;
- and
- a conductor pattern formed on the front surface, the conductor pattern including a plurality of interdigital transducers (IDTs) of a respective plurality of acoustic resonators, interleaved fingers of each of the plurality of IDTs disposed on the piezoelectric plate, wherein each of the IDTs are configured to excite respective shear primary acoustic modes in the piezoelectric plate in response to respective radio frequency signals applied to each IDT, wherein at least one finger of at least one of the plurality of IDTs is disposed in a groove in the piezoelectric plate, and wherein a depth of the groove is less than or equal to a thickness of the at least one finger.
2 more elements
A filter device, comprising:
- a substrate;
- a piezoelectric plate having front and back surfaces;
- an acoustic Bragg reflector between the surface of the substrate and the back surf ace of the piezoelectric plate;
- and
- a conductor pattern formed on the front surface, the conductor pattern including a plurality of interdigital transducers (IDTs) of a respective plurality of acoustic resonators, interleaved fingers of each of the plurality of IDTs disposed on the piezoelectric plate, wherein each of the IDTs are configured to excite respective shear primary acoustic modes in the piezoelectric plate in response to respective radio frequency signals applied to each IDT, wherein at least one finger of at least one of the plurality of IDTs is disposed in a groove in the piezoelectric plate, and wherein the piezoelectric plate is a rotated z-cut lithium niobate plate.
2 more elements
Dependencies are inferred from the claim text.