Abstract: An acoustic wave device is disclosed. the acoustic wave device is configured to generate a wave having a wavelength of L. The acoustic wave device includes a piezoelectric layer a first layer of an interdigital transducer electrode over the piezoelectric layer, and a second layer of the interdigital transducer electrode over the first layer. The first layer has a material with a first mass density of ?. The first mass density of ? is greater than 5000 kg/m3. The first layer has a thickness of t1 less than 0.04 L. The first layer can have the thickness of t1 in a range between 0.0025 L(10220/?) and 0.04 L(10220/?). The second layer has a material with a second mass density that is smaller than the first mass density.

Abstract: A method of manufacturing an acoustic wave device is provided. The method of manufacturing the acoustic wave device comprises providing a layer of piezoelectric material, disposing a pair of interdigital transducer electrodes on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar towards an edge region of the interdigital transducer electrode at the distal ends of the electrode fingers, and etching trench portions into the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The formation of the trench portions through etching results in an easier fabrication, that is less likely to damage the interdigital transducer electrodes.

Abstract: An acoustic wave device, a radio frequency filter and an electronics module are provided. The acoustic wave device comprises a layer of piezoelectric material, a pair of interdigital transducer electrodes disposed on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar towards an edge region of the interdigital transducer electrode at the distal ends of the electrode fingers, and trench portions located in the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The acoustic wave device provides effective suppression of transverse modes.

Abstract: An acoustic wave device, a radio frequency filter and an electronics module are provided. The acoustic wave device, comprises a layer of piezoelectric material, a pair of interdigital transducer electrodes disposed on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar through a central region of the interdigital transducer electrode towards an edge region of the interdigital transducer electrode, each of the plurality of electrode fingers having a width in a direction perpendicular to the extension of the electrode fingers that is smaller in the edge regions than in the central regions, and trench portions located in the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The acoustic wave device provides effective suppression of transverse modes.

Abstract: A temperature coefficient of frequency compensated surface acoustic wave device is provided which includes: a piezoelectric substrate, an interdigital transducer configured to generate a surface acoustic wave in response to an electrical signal and a first temperature compensation layer disposed on the piezoelectric substrate, the interdigital transducer being disposed on the temperature compensation layer.

Abstract: A temperature compensated surface acoustic wave device is disclosed. The temperature compensated surface acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode over the piezoelectric layer, and a temperature compensation layer over the interdigital transducer electrode. The interdigital transducer electrode includes a first layer, a second layer over the first layer, and a buffer layer between the first layer and the second layer. A thermal conductivity of the second layer is greater than a thermal conductivity of the buffer layer. The buffer layer can be a titanium layer. A thickness of the buffer layer can be in a range of 20 nm to 200 nm, or in a range of 5% to 30% of a thickness of the interdigital transducer electrode.

Abstract: Aspects of this disclosure relate to a surface acoustic wave device. The surface acoustic wave device includes a piezoelectric layer and an interdigital transducer. The interdigital transducer electrode includes a pair of electrodes, each electrode having a bus bar and fingers extending from the bus bar. The interdigital transducer electrode has an interdigital region defined by a portion of the fingers of the electrodes that interdigitate with each other. A dielectric layer is disposed over the interdigital transducer electrode outside the interdigital region and configured to reduce a loss of the surface acoustic wave device.

Abstract: An acoustic wave device comprises a substrate including a piezoelectric material, interdigital transducer (IDT) electrodes including interdigitated electrode fingers disposed on a surface of the substrate, and a passivation layer formed on tops of the IDT electrodes and on the piezoelectric material in gaps between adjacent IDT electrodes, the passivation film being thicker on the tops of the IDT electrodes than on the piezoelectric material in the gaps between adjacent IDT electrodes to improve an electromechanical coupling factor of the acoustic wave device.

Abstract: Aspects of this disclosure relate to acoustic wave devices on stacked die. A first die can include first acoustic wave device configured to generate a boundary acoustic wave. A second die can include a second acoustic wave device configured to generate a second boundary acoustic wave, in which the second die is stacked with the first die. The first acoustic wave resonator can include a piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and high acoustic velocity layers on opposing sides of the piezoelectric layer. The high acoustic velocity layers can each have an acoustic velocity that is greater than a velocity of the boundary acoustic wave.

Abstract: A surface acoustic wave (SAW) resonator comprises a plurality of interdigital transducer electrodes disposed on a multilayer piezoelectric substrate (MPS) including a layer of piezoelectric material having a lower surface bonded to an upper surface of a layer of a second material different from the piezoelectric material that improves the temperature stability and reliability of the SAW resonator, and a layer of dielectric material disposed on an upper surface of the interdigital transducer electrodes and MPS.

Abstract: Acoustic wave resonators are disclosed that include a piezoelectric layer and an interdigital transducer electrode over the piezoelectric layer. The interdigital transducer electrode has a rotation angle and a tilt angle. The rotation angle and the tilt angle can together increase a figure of merit of the acoustic wave device. The rotation angle and the tilt angle can both be non-zero.

Abstract: A surface acoustic wave (SAW) resonator comprises a plurality of interdigital transducer (IDT) electrodes disposed on a multilayer piezoelectric substrate including a layer of piezoelectric material having a lower surface bonded to an upper surface of a layer of a dielectric material. The dielectric material has a lower surface bonded to an upper surface of a carrier substrate. The plurality of IDT electrodes include an upper layer and a lower layer. The upper layer is formed of a material having a higher conductivity than the lower layer. The lower layer is formed of a material having a higher density than the upper layer to provide for reduction in size of the SAW resonator.

Abstract: Aspects of this disclosure relate to an acoustic wave resonator with transverse mode suppression. The acoustic wave resonator can include a piezoelectric layer, an interdigital transducer electrode, a temperature compensation layer, and a mass loading strip. The mass loading strip can be a conductive strip. The mass loading strip can overlap edge portions of fingers of the interdigital transducer electrode. A layer of the mass loading strip can have a density that is at least as high as a density of a material of the interdigital transducer electrode. The material of the interdigital transducer can impact acoustic properties of the acoustic wave resonator.

Abstract: A method of making an electronics package with a multi-layer piezoelectric substrate includes bonding a piezoelectric layer over a substrate. The method also includes applying a polyimide layer over an outer boundary of the piezoelectric layer so that the polyimide layer is interposed between the piezoelectric layer and a metal portion (e.g., of copper (Cu)) to inhibit (e.g., prevent) stresses from the metal layer damaging the piezoelectric layer.

Abstract: An acoustic wave device has a multilayer piezoelectric substrate (MPS) structure and a multilayer interdigital transducer electrode (IDT). The multilayer piezoelectric substrate includes a piezoelectric layer over a support substrate. An additional (functional) layer can optionally be interposed between the piezoelectric layer and the support substrate, which can facilitate bonding between these layers and provide temperature compensation. The multilayer IDT is disposed over the piezoelectric layer and includes a first layer of a first material with higher density and a second layer of a different material with lower density. The interdigital transducer electrode also includes (mass loading) strips disposed over (e.g., adjacent, in contact with) the second layer, which advantageously facilitate suppression of transverse mode.

Abstract: An electronics package has a multi-layer piezoelectric substrate with a piezoelectric layer over a substrate. The outer boundary of the piezoelectric layer is covered with a polyimide layer so that the polyimide layer is interposed between the piezoelectric layer and a metal portion (e.g., of copper (Cu)) to inhibit (e.g., prevent) stresses from the metal layer damaging the piezoelectric layer..

Abstract: A method of manufacturing an acoustic wave device includes forming a multilayer piezoelectric substrate by forming a piezoelectric layer and forming a support substrate below the piezoelectric layer. The method also includes forming an interdigital transducer electrode including forming a first layer disposed over the piezoelectric layer, forming a second layer disposed over the first layer, the second layer being of a less dense material than the first layer, forming a third layer disposed over the second layer. The method also includes etching the third layer to form a pair of strips extending over one or more fingers of the interdigital transducer electrode and having a density that suppresses a transverse mode of the acoustic wave device.

Abstract: Aspects of this disclosure relate to a boundary acoustic wave device. The boundary acoustic wave device can include two low acoustic impedance layers, an interdigital transducer electrode, piezoelectric material positioned between the interdigital transducer electrode and each of the two low acoustic impedance layers, and two high acoustic impedance substrates. The two low acoustic impedance layers can be positioned between the two high acoustic impedance substrates. Related acoustic wave filters, multiplexers, radio frequency modules, wireless communication devices, and methods are disclosed.

Abstract: An acoustic wave device is disclosed. The acoustic wave device can include a multilayer piezoelectric substrate and an interdigital transducer electrode over the multilayer piezoelectric substrate. The interdigital transducer electrode includes a first layer and a second layer over the first layer. The interdigital transducer electrode has a tilt angle of at least 12 degrees. The acoustic wave device being configured to generate a surface acoustic wave having a wavelength L.

Abstract: An acoustic wave device is disclosed. The acoustic wave device can include a multilayer piezoelectric substrate and an interdigital transducer electrode over the multilayer piezoelectric substrate. The interdigital transducer electrode includes a first layer and a second layer over the first layer. The interdigital transducer electrode has a non-zero tilt angle that provides an improved quality factor as compared to a zero tilt angle. The acoustic wave device is configured to generate a surface acoustic wave having a wavelength L. A total number of fingers of the interdigital transducer electrode is between 50 L and 100 L. A width between a finger of the interdigital transducer electrode and an adjacent finger of interdigital transducer electrode is between 20 L and 40 L.