A method for fabricating a surface acoustic wave (SAW) device includes forming an interdigital transducer (IDT) having lead-out portions and arrays of interdigital electrodes on a substrate, wherein the interdigital electrodes include central portions, end portions, and intermediate portions between the end portions and the lead-out portions; forming a protective layer on the IDT; forming a first temperature compensation layer on the protective layer; forming openings in the first temperature compensation layer to expose portions of the protective layer on the central portions and the intermediate portions of the interdigital electrodes; and etching the exposed portions of the protective layer, and etching the central portions and the intermediate portions of the interdigital electrodes to a preset thickness, to form protruding structures at the end portions of the interdigital electrodes.

A surface acoustic wave (SAW) filter package structure includes a dielectric substrate having a dielectric layer, a first patterned conductive layer, a second patterned conductive layer, and a conductive connection layer. The conductive connection layer is electrically connected between the first patterned conductive layer and the second patterned conductive layer, which are disposed at opposite sides of the dielectric layer. The second patterned conductive layer has a finger electrode portion. An active surface of a chip is faced toward the finger electrode portion. A polymer sealing frame is disposed between the chip and the dielectric substrate and surrounds the periphery of the chip to form a chamber together with the chip and the dielectric substrate. The mold sealing layer is disposed on the dielectric substrate and covers the chip and the polymer sealing frame. A manufacturing method of the SAW filter package structure is also disclosed.

A hybrid structure for a surface acoustic wave device comprises a useful layer of piezoelectric material having a first free surface and a second surface disposed on a support substrate that has a lower coefficient of thermal expansion than that of the useful layer, wherein the useful layer comprises an area of nanocavities.

A hybrid structure for a surface acoustic wave device comprises a useful layer of piezoelectric material having a first free surface and a second surface disposed on a support substrate that has a lower coefficient of thermal expansion than that of the useful layer, wherein the useful layer comprises an area of nanocavities.

A process for transferring a thin layer consisting of a first material to a support substrate consisting of a second material having a different thermal expansion coefficient, comprises providing a donor substrate composed of an assembly of a thick layer formed of the first material and of a handle substrate having a thermal expansion coefficient similar to that of the support substrate, and the donor substrate having a main face on the side of the thick laver; introducing light species into the thick layer to generate a plane of weakness therein and to define the thin layer between the plane of weakness and the main face of the donor substrate; assembling the main face of the donor substrate with a face of the support substrate; and detachment of the thin layer at the plane of weakness, the detachment comprising application of a heat treatment.

A process for transferring a thin layer consisting of a first material to a support substrate consisting of a second material having a different thermal expansion coefficient, comprises providing a donor substrate composed of an assembly of a thick layer formed of the first material and of a handle substrate having a thermal expansion coefficient similar to that of the support substrate, and the donor substrate having a main face on the side of the thick laver; introducing light species into the thick layer to generate a plane of weakness therein and to define the thin layer between the plane of weakness and the main face of the donor substrate; assembling the main face of the donor substrate with a face of the support substrate; and detachment of the thin layer at the plane of weakness, the detachment comprising application of a heat treatment.

A method of manufacturing a composite substrate that includes bonding a silicon (Si) wafer having an interstitial oxygen concentration of 2 to 10 ppma to a piezoelectric material substrate as a support substrate, and thinning the piezoelectric material substrate after the bonding. The piezoelectric material substrate is particularly preferably a lithium tantalate wafer (LT) substrate or a lithium niobate (LN) substrate.

A method of manufacturing a composite substrate that includes bonding a silicon (Si) wafer having an interstitial oxygen concentration of 2 to 10 ppma to a piezoelectric material substrate as a support substrate, and thinning the piezoelectric material substrate after the bonding. The piezoelectric material substrate is particularly preferably a lithium tantalate wafer (LT) substrate or a lithium niobate (LN) substrate.

A multilayer piezoelectric substrate acoustic wave device is disclosed. The multilayer piezoelectric substrate acoustic wave device can include a multilayer piezoelectric substrate, an interdigital transducer electrode over the multilayer piezoelectric substrate, and a multilayer passivation structure over the interdigital transducer electrode. The multilayer passivation structure includes a first layer that has a first passivation material and a second layer that has a second passivation material different from the first passivation material.

An acoustic wave device is disclosed. The acoustic wave device can include a piezoelectric layer, an interdigital transducer electrode formed with the piezoelectric layer, a temperature compensation layer over the interdigital transducer electrode. The interdigital transducer electrode includes a bus bar and fingers that extend from the bus bar. The fingers each includes an edge portion and a body portion. The acoustic wave device can include a mass loading strip overlaps the edge portions of the fingers. The acoustic wave device can include a portion of the temperature compensation layer is positioned between the mass loading strip and the piezoelectric layer. The acoustic wave device can include a buffer layer that is disposed at least partially between the mass loading strip and the temperature compensation layer. The buffer layer can have a coefficient of thermal expansion greater than a coefficient of thermal expansion of the temperature compensation layer and less than a coefficient of thermal expansion of the mass loading strip.