An acoustic wave device includes a piezoelectric layer and an interdigital transducer electrode disposed over the piezoelectric layer. The interdigital transducer electrode is thicker in a center region of the interdigital transducer electrode than in a gap region of the interdigital transducer electrode to thereby reduce a mass loading of the interdigital transducer electrode in the gap region. The interdigital transducer electrode has a layer of more dense material disposed of a layer of less dense material.

An acoustic wave device includes a piezoelectric layer and an interdigital transducer electrode disposed over the piezoelectric layer. The interdigital transducer electrode is thicker in a center region of the interdigital transducer electrode than in a gap region of the interdigital transducer electrode to thereby reduce a mass loading of the interdigital transducer electrode in the gap region. The interdigital transducer electrode has a layer of more dense material disposed of a layer of less dense material.

An acoustic wave device is disclosed. The acoustic wave device includes a support layer, a ceramic layer positioned over the support layer, a piezoelectric layer positioned over the ceramic layer, and an interdigital transducer electrode positioned over the piezoelectric layer. The support layer has a higher thermal conductivity than the ceramic layer. The ceramic layer can be a polycrystalline spinel layer. The acoustic wave device can be a surface acoustic wave device configured to generate a surface acoustic wave.

An acoustic wave device is disclosed. The acoustic wave device includes a support layer, a ceramic layer positioned over the support layer, a piezoelectric layer positioned over the ceramic layer, and an interdigital transducer electrode positioned over the piezoelectric layer. The support layer has a higher thermal conductivity than the ceramic layer. The ceramic layer can be a polycrystalline spinel layer. The acoustic wave device can be a surface acoustic wave device configured to generate a surface acoustic wave.

An acoustic wave device is disclosed. The acoustic wave device includes a support layer, a ceramic layer positioned over the support layer, a piezoelectric layer positioned over the ceramic layer, and an interdigital transducer electrode positioned over the piezoelectric layer. The support layer has a higher thermal conductivity than the ceramic layer. The ceramic layer can be a polycrystalline spinel layer. The acoustic wave device can be a surface acoustic wave device configured to generate a surface acoustic wave.

An acoustic wave device is disclosed. The acoustic wave device includes a support layer, a ceramic layer positioned over the support layer, a piezoelectric layer positioned over the ceramic layer, and an interdigital transducer electrode positioned over the piezoelectric layer. The support layer has a higher thermal conductivity than the ceramic layer. The ceramic layer can be a polycrystalline spinel layer. The acoustic wave device can be a surface acoustic wave device configured to generate a surface acoustic wave.

Aspects include devices and methods for frequency tuned piezoelectric devices. In some aspects, a device includes a piezoelectric layer, a metallization layer comprising an interdigital transducer formed on a top surface of the piezoelectric layer, where the interdigital transducer comprises interleaved electrode fingers, a dielectric layer formed over the piezoelectric layer and the metallization layer, and where a first dielectric layer thickness over top surfaces of the interleaved electrode fingers is thinner than a second dielectric layer thickness over the piezoelectric layer between adjacent electrode fingers of the interleaved electrode fingers.

Aspects include devices and methods for frequency tuned piezoelectric devices. In some aspects, a device includes a piezoelectric layer, a metallization layer comprising an interdigital transducer formed on a top surface of the piezoelectric layer, where the interdigital transducer comprises interleaved electrode fingers, a dielectric layer formed over the piezoelectric layer and the metallization layer, and where a first dielectric layer thickness over top surfaces of the interleaved electrode fingers is thinner than a second dielectric layer thickness over the piezoelectric layer between adjacent electrode fingers of the interleaved electrode fingers.

Provided is a method of manufacturing a composite substrate equipped with a piezoelectric single-crystal film having good film-thickness uniformity and not causing deterioration in properties even if ion implantation is performed. The method of manufacturing a composite substrate 10 equipped with a piezoelectric single-crystal film 11 according to the present invention includes the steps of: (a) subjecting a piezoelectric single-crystal substrate 1 made of lithium tantalate or lithium niobate to ion implantation treatment to form an ion implantation layer 11, (c) bonding the surface of the piezoelectric single-crystal substrate 1 having the ion implantation layer 11 thereon to a temporary bonding substrate 2, (d) separating the piezoelectric single-crystal substrate 1 into the ion implantation layer 11 and the remaining portion of the substrate to form a piezoelectric single-crystal film 11 on the temporary bonding substrate 2, (f) bonding a supporting substrate 3 to the surface of the piezoelectric single-crystal film 11 opposite to a bonded surface of the temporary bonding substrate, and (g) separating the temporary bonding substrate from the piezoelectric single-crystal film 11.

Provided is a method of manufacturing a composite substrate equipped with a piezoelectric single-crystal film having good film-thickness uniformity and not causing deterioration in properties even if ion implantation is performed. The method of manufacturing a composite substrate 10 equipped with a piezoelectric single-crystal film 11 according to the present invention includes the steps of: (a) subjecting a piezoelectric single-crystal substrate 1 made of lithium tantalate or lithium niobate to ion implantation treatment to form an ion implantation layer 11, (c) bonding the surface of the piezoelectric single-crystal substrate 1 having the ion implantation layer 11 thereon to a temporary bonding substrate 2, (d) separating the piezoelectric single-crystal substrate 1 into the ion implantation layer 11 and the remaining portion of the substrate to form a piezoelectric single-crystal film 11 on the temporary bonding substrate 2, (f) bonding a supporting substrate 3 to the surface of the piezoelectric single-crystal film 11 opposite to a bonded surface of the temporary bonding substrate, and (g) separating the temporary bonding substrate from the piezoelectric single-crystal film 11.