Abstract: Acoustic resonators and filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern including a multi-mark interdigital transducer (IDT), fingers of the IDT on the diaphragm. A thickness between the front and back surfaces is greater than or equal to 200 nm and less than or equal to 1000 nm.

Abstract: Acoustic resonators and filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, the back surface attached to a surface of a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate, and a conductor pattern on the front surface, the conductor pattern including an interdigital transducer (IDT), interleaved fingers of the IDT on the diaphragm. A ratio of a mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.12 and less than or equal to 0.3. A thickness between the front and back surfaces is greater than or equal to 200 nm and less than or equal to 1000 nm.

Abstract: Filter devices are disclosed. A filter device includes a piezoelectric plate comprising a supported portion, a first diaphragm, and a second diaphragm. The supported portion is attached to a substrate and the first and second diaphragms spans respective cavities in the substrate. A first interdigital transducer (IDT) has interleaved fingers on the first diaphragm. A second interdigital transducer (IDT) has interleaved fingers on the second diaphragm. A first dielectric layer is between the interleaved fingers of the first IDT, and a second dielectric layer is between the interleaved fingers of the second IDT. A thickness of the first dielectric layer is greater than a thickness of the second dielectric layer. The piezoelectric plate and the first and second IDTs are configured such that radio frequency signals applied to first and second IDTs excite primary shear acoustic modes in the respective diaphragms.

Abstract: Acoustic resonators and filter devices, and method of making acoustic resonators and filter devices. An acoustic resonator is provided that includes a piezoelectric layer; and an interdigital transducer (IDT) having interleaved fingers on a surface of the piezoelectric layer. At least one finger of the interleaved fingers has an irregular hexagon cross-sectional shape. Moreover, sides of the irregular hexagon cross-sectional shape are not all a same length.

Abstract: Acoustic resonators, acoustic filter devices and methods of making the same. An acoustic resonator device includes a piezoelectric layer having front and back surfaces, a high acoustic velocity layer on the back surface, and an interdigital transducer (IDT) on the front surface. The high acoustic velocity layer has a higher acoustic velocity than an acoustic velocity of the piezoelectric layer.

Abstract: A filter device is provided that includes a substrate comprising a base and an intermediate layer; a piezoelectric layer coupled to the substrate; a first interdigital transducer (IDT) of a first bulk acoustic resonator device on the piezoelectric layer and having interleaved fingers over a first cavity the first bulk acoustic resonator device; a second IDT of a second bulk acoustic resonator device on the piezoelectric layer and having interleaved fingers over a second cavity of the second bulk acoustic resonator device; a first dielectric layer having a first thickness disposed on the piezoelectric layer and between the interleaved fingers of the first IDT; and a second dielectric layer having a second thickness disposed on the piezoelectric layer and between the interleaved fingers of the second IDT. Moreover, the first thickness is greater than the second thickness.

Abstract: There is disclosed acoustic resonators and filter devices. An acoustic resonator includes a single-crystal piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm. 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. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm.

Abstract: Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate, a lithium niobate plate having front and back surfaces, wherein Euler angles of the lithium niobate plate are [0°, ?, 0°], where ? is greater than or equal to 0° and less than or equal to 60°, and an acoustic Bragg reflector between the surface of the substrate and the back surface of the lithium niobate plate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate. At least one finger of the IDT is disposed in a groove in the lithium niobate plate.

Abstract: A bulk acoustic resonator is provided that includes a piezoelectric layer, and an interdigital transducer on a surface of the piezoelectric layer and including a plurality of interleaved fingers. At least one finger of the plurality of interleaved fingers comprises a first layer having a bottom surface that contacts the surface of the piezoelectric layer. The at least one finger includes a second layer having a bottom surface that contacts a top surface of the first layer. Moreover, a width of the bottom surface of the second layer is less than a width of the bottom surface of the first layer.

Abstract: An acoustic resonator is provided. The acoustic resonator may comprise a substrate, a piezoelectric membrane attached to the substrate, and a plurality of electrodes. The piezoelectric membrane presents a plurality of grooves, wherein two adjacent grooves define a ridge in between them. Each electrode is placed in a respective groove. Each electrode comprises two lateral parts, each lateral part covering at least partially a respective lateral wall of the groove.

Abstract: Acoustic resonator devices, filter devices, and methods of fabrication are disclosed. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces. The back surface is attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. 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. The IDT is configured to excite a primary acoustic mode in the diaphragm in response to a radio frequency signal applied to the IDT. At least a portion of an edge of the diaphragm is at an oblique angle to the fingers.

Abstract: Resonator devices are disclosed. An acoustic resonator device includes a piezoelectric plate having front and back surfaces, an acoustic Bragg reflector on the back surface, and an interdigital transducer (IDT) on the front surface. The acoustic Bragg reflector reflects a primary shear acoustic mode excited by the IDT in the piezoelectric plate over a frequency range including a resonance frequency and an anti-resonance frequency of the acoustic resonator device.

Abstract: Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate, a lithium niobate plate having front and back surfaces, wherein Euler angles of the lithium niobate plate are [0°, ?, 0°], where ? is greater than or equal to 0° and less than or equal to 60°. An interdigital transducer (IDT) is formed on the piezoelectric plate.

Abstract: An acoustic resonator device is provided that includes a piezoelectric layer; and an interdigital transducer (IDT) at a surface of the piezoelectric layer, the IDT comprising interleaved fingers. At least one interleaved finger of the interleaved fingers comprises a first layer and a second layer over the first layer, wherein the first layer is between the piezoelectric layer and the second layer. Moreover, a shape of the second layer varies with respect to at least one other interleaved finger of the interleaved fingers. A thickness of the first layer is less than a thickness of the second layer.

Abstract: Resonator and filter devices and methods of fabrication. A resonator chip includes a substrate, a piezoelectric plate, and an acoustic Bragg reflector between the substrate and a back surface of the piezoelectric plate. A conductor pattern on a surface of the piezoelectric plate includes a first plurality of contact pads and an interdigital transducer (IDT). The acoustic Bragg reflector is configured to reflect the shear primary acoustic mode. An interposer has a second plurality of contact pads on a back surface. A seal connects a perimeter of the piezoelectric plate to a perimeter of the interposer. Each contact pad of the first plurality of contact pads is directly connected to a respective contact pad of the second plurality of contact pads.

Abstract: There is disclosed acoustic resonators and filter devices. An acoustic resonator device includes a piezoelectric plate, and an interdigital transducer (IDT) formed on a front surface of the piezoelectric plate. The IDT includes interleaved fingers. At least one of the interleaved fingers includes a first layer adjacent the piezoelectric plate and a second layer over the first layer, wherein a width of the first layer is constant, and wherein a width of the second layer varies along a length of the at least one interleaved finger.

Abstract: Acoustic filters, resonators and methods are disclosed. An acoustic filter device includes a substrate; a piezoelectric layer attached to the substrate, wherein at least a portion of the piezoelectric layer is disposed over a cavity of the acoustic resonator device; and an interdigital transducer (IDT) on a surface of the piezoelectric layer, the IDT including interleaved fingers extending at least over the portion of the piezoelectric layer disposed over the cavity. The cavity has at least one rounded corner, and a portion of interleaved fingers extend from at least one busbar. Moreover, at least a portion of the rounded corner of the cavity is under the at least one busbar in a plan view of the piezoelectric layer.

Abstract: An acoustic resonator device, filter devices, and methods of making the same. An acoustic resonator device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces, where the back surface is attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. The device further includes an interdigital transducer formed on the front surface of the piezoelectric plate, where interleaved fingers of the IDT disposed on the diaphragm are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm. The interleaved fingers include a first layer adjacent the diaphragm and a second layer over the first layer, the second layer having a narrower width than the first layer.

Abstract: A filter device is provided that includes a substrate; a piezoelectric layer coupled to the substrate either directly or via one or more intermediate layers; a first interdigital transducer (IDT) of a first bulk acoustic resonator device on the piezoelectric layer and having interleaved fingers over a first cavity the first bulk acoustic resonator device; a second IDT of a second bulk acoustic resonator device on the piezoelectric layer and having interleaved fingers over a second cavity of the second bulk acoustic resonator device; a first dielectric layer having a first thickness disposed between the interleaved fingers of the first IDT; and a second dielectric layer having a second thickness disposed between the interleaved fingers of the second IDT. The first thickness is greater than the second thickness.

Abstract: Acoustic resonator devices and acoustic filter devices. An acoustic resonator includes a piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm, and a conductor pattern on the front surface, the conductor pattern comprising an interdigital transducer (IDT), interleaved fingers of the IDT on the diaphragm. A ratio of a mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.12 and less than or equal to 0.3. A thickness of the interleaved fingers is greater than or equal to 0.85 times a thickness of the piezoelectric plate and less than or equal to 2.5 times the thickness of the piezoelectric plate.