An acoustic wave component is disclosed. The acoustic wave component can include a bulk acoustic wave resonator and a surface acoustic wave device. The bulk acoustic wave resonator can include a first portion of a glass substrate, a first piezoelectric layer positioned on the glass substrate, and electrodes positioned on opposing sides of the first piezoelectric layer. The surface acoustic wave device can include a second portion of the glass substrate, a second piezoelectric layer positioned on the glass substrate, and an interdigital transducer electrode on the second piezoelectric layer.

There are disclosed acoustic resonators and radio frequency filter devices. A back surface of a single-crystal piezoelectric plate is attached to a surface of a substrate except for portions of the piezoelectric plate forming a plurality of diaphragms, each of which spans a respective cavity in the substrate. A conductor pattern is formed on the front surface, the conductor pattern including interdigital transducers (IDTs) of one or more pairs of sub-resonators, each pair consisting of two sub-resonators. The IDT of each sub-resonator includes interleaved fingers disposed on a respective diaphragm. The piezoelectric plate and the IDTs are configured such that respective radio frequency signals applied to each IDT excite respective shear primary acoustic modes in the respective diaphragms. The two sub-resonators of each pair of sub-resonators are positioned symmetrically about a central axis.

[PROBLEM TO BE SOLVED] To provide a bulk wave resonator having a high frequency passband.

[SOLUTION] A bulk wave resonator using a bulk wave, includes a support substrate, an acoustic multilayer film that includes, stacked on the support substrate, a plurality of types of dielectrics having different acoustic impedances, a piezoelectric layer that is stacked on the acoustic multilayer film, a first electrode, and a second electrode. The first and second electrodes are disposed to face each other with a gap therebetween on a first surface of the piezoelectric layer opposite to the acoustic multilayer film, and are applied with a voltage for allowing the piezoelectric layer to generate the bulk wave. A direction that is parallel to the surface of the piezoelectric layer and in which the first electrode and the second electrode face each other is defined as a first direction. The bulk wave resonator uses, as a main mode, a bulk wave in the first direction that is generated by a thickness shear vibration in the first direction, which is excited by a parallel electric field formed in the piezoelectric layer when a voltage applied to the first electrode and the second electrode.

Provided is a bulk acoustic wave resonator. The bulk acoustic wave resonator includes an upper electrode, a piezoelectric layer and a lower electrode. The piezoelectric layer is disposed between the upper electrode and the lower electrode. At least one boundary of an orthogonal projection of the piezoelectric layer on the lower electrode includes a plurality of sawtooth structures.

An acoustic wave filter includes a first ladder circuit including a first series arm resonator and a first parallel arm resonator, a second ladder circuit including a second series arm resonator and a second parallel arm resonator, and a third ladder circuit including a third series arm resonator and a third parallel arm resonator. The first, second and third ladder circuits are cascade-connected in order. A condition of fas1>fas2>fas3>frp1>frp2>frp3 is satisfied, where fas1 represents an anti-resonant frequency of the first series arm resonator, fas2 represents an anti-resonant frequency of the second series arm resonator, fas3 represents an anti-resonant frequency of the third series arm resonator, frp1 represents a resonant frequency of the first parallel arm resonator, frp2 represents a resonant frequency of the second parallel arm resonator, and frp3 represents a resonant frequency of the third parallel arm resonator.

The present disclosure provides a bulk acoustic wave resonator, a manufacturing method thereof, and a filter, wherein the bulk acoustic wave resonator includes: a substrate; an acoustic reflection unit on the substrate; a piezoelectric stack structure on the acoustic reflection unit; and a pad on the piezoelectric stack structure; wherein the pad has an overlapping region with the acoustic reflection unit. The acoustic wave resonator, the manufacturing method thereof and the filter of the present disclosure can effectively reduce connection resistance of the bulk acoustic wave resonator, thereby reducing insertion loss of the filter.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate and a lithium niobate (LN) plate having front and back surfaces and a thickness ts. The back surface is attached to a surface of the substrate. A portion of the LN plate forms a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the LN plate with interleaved fingers of the IDT disposed on the diaphragm. The LN plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic wave in the diaphragm. Euler angles of the LN plate are [0°, β, 0°], where 0≤β≤60°. A thickness of the interleaved fingers of the IDT is greater than or equal to 0.8 ts and less than or equal to 2.0 ts.

Acoustic resonator devices and methods are disclosed. An acoustic resonator device includes a substrate having a surface and a piezoelectric plate having front and back surfaces. The back surface of the piezoelectric plate 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 piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. One or more diaphragm support pedestals extend between the substrate and the diaphragm within the cavity.

Disclosed is an air-gap type film bulk acoustic resonator (FBAR) including a substrate including an air-gap portion on a top surface, a lower electrode having a polygonal plate shape above the substrate and configured to surround a top of the air-gap portion, a piezoelectric layer formed above the lower electrode, and an upper electrode formed above the piezoelectric layer. Here, the lower electrode includes an electrode non-deposited area formed between one side plate boundary surface of the polygonal plate and one side air-gap boundary surface of the air-gap portion to expose one part of a top of the air-gap portion.