A vibration detection element includes substrates, support members, and an oscillator, and may be used as a biosensor and/or for liquid inspection by analysis of oscillator resonant frequency change. The substrates have a space portion, and the support members protrude from the surfaces of the respective substrates into the space portion. The oscillator is disposed between the support members and is capable of vibrating in the space portion. The support members may each include multiple supports which prevent the oscillator from contacting the substrate surfaces. During manufacturing the oscillator may be transferred from the support member of a glass flow path substrate to a silicon flow path substrate by placement of the silicon substrate support member against the oscillator and subsequent removal of the adhesive from the glass substrate support member.

A method of manufacturing a substrate for an acoustic wave device includes: a substrate joining step of joining a piezoelectric material layer to a surface on one side of a support substrate; a grinding step of grinding the piezoelectric material layer; a removal amount map forming step of measuring in-plane thickness of the piezoelectric material layer by an optical thickness meter, and calculating a removal amount for the piezoelectric material layer for adjusting thickness variability of the piezoelectric material layer to or below a threshold on the basis of each coordinate in the plane, to form a removal amount map; a laser processing step of applying a pulsed laser beam of such a wavelength as to be absorbed in the piezoelectric material layer, to selectively remove the piezoelectric material layer, based on the removal amount map; and a polishing step of polishing the surface of the piezoelectric material layer.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. Patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the electrodes and a planarized support layer is deposited over the sacrificial layer. The device can include temperature compensation layers (TCL) that improve the device TCF. These layers can be thin layers of oxide type materials and can be configured between the top electrode and the piezoelectric layer, between the bottom electrode and the piezoelectric layer, between two or more piezoelectric layers, and any combination thereof. In an example, the TCLs can be configured from thick passivation layers overlying the top electrode and/or underlying the bottom electrode.

A method for fabricating an array of front ends for an array of packaged electronic components that each comprise: an electrical element packaged within a package comprising a front part of a package comprising an inner section with a cavity therein opposite the resonator defined by the raised frame and an outer section sealing said cavity; and a back part of the package comprising a back cavity in an inner back section, and an outer back section sealing the cavity, said back package further comprising a first and a second via through the back end around said at least one back cavity for coupling to front and back electrodes of the electronic component; the vias terminating in external contact pads that are coupleable in a ‘flip chip’ configuration to a circuit board; the method comprising the stages of: i. Obtaining a carrier substrate having an active membrane layer attached thereto by its rear surface, with a front electrode on the front surface of the active membrane layer; ii. Obtaining an inner front end section; iii. Attaching the inner front end section to the exposed front surface of the front electrode; iv. Detaching the carrier substrate from the rear surface of the active membrane layer; v. Optionally thinning the inner front section; vi. Processing the rear surface by removing material to create an array of at least one island of active membrane on at least one island of front electrode; vii. Creating an array of at least one front cavity by selectively removing at least outer layer of the inner front end section, such that there is one cavity opposite each island of membrane on the front side of the front electrode on the opposite side to the island of active membrane; viii. Applying an outer front end section to the inner front end section and bonding the outer front end section to an outer surface of the inner front end section such that the outer front end section spans across and seals the at least one cavity of the array of front cavities.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. One or more patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the one or more electrodes and a planarized support layer is deposited over the sacrificial layer. The support layer is etched to form one or more cavities overlying the electrodes to expose the sacrificial layer. The sacrificial layer is etched to release the cavities around the electrodes. Then, a cap layer is fusion bonded to the support layer to enclose the electrodes in the support layer cavities.

A method for processing a lithium tantalate crystal substrate includes providing a lithium tantalate crystal substrate, roughening the lithium tantalate crystal substrate, providing a catalytic agent, bringing the lithium tantalate crystal substrate and the catalytic agent into contact with each other after the lithium tantalate crystal substrate is roughened, and subjecting the lithium tantalate crystal substrate to a reduction treatment. The reduction treatment is conducted at a temperature not higher than a Curie temperature of the lithium tantalate crystal substrate. The catalytic agent is selected from the group consisting of metal powder, metal gas, and metal carbonate powder.

A bonded body includes a supporting substrate, a silicon oxide layer provided on the supporting substrate, and a piezoelectric material substrate provided on the silicon oxide layer and composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate. The surface resistivity of the piezoelectric material substrate on the side of the silicon oxide layer is 1.7×10.sup.1 5Ω/□ or higher.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. A first patterned electrode is deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the first electrode and a planarized support layer is deposited over the sacrificial layer, which is then bonded to a substrate wafer. The crystalline substrate is removed and a second patterned electrode is deposited over a second surface of the film. The sacrificial layer is etched to release the air reflection cavity. Also, a cavity can instead be etched into the support layer prior to bonding with the substrate wafer. Alternatively, a reflector structure can be deposited on the first electrode, replacing the cavity.

A bonded body includes a supporting substrate; a piezoelectric material substrate composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate; and a bonding layer bonding the supporting substrate and the piezoelectric material substrate and contacting a main surface of the piezoelectric material substrate. The bonding layer includes a void extending from the piezoelectric material substrate toward the supporting substrate. A ratio (t2/t1) of a width t2 at an end of the void on a side of the supporting substrate with respect to a width t1 at an end of the void on a side of the piezoelectric material substrate is 0.8 or lower.

The present disclosure provides a resonator and its fabrication method. The method includes providing a first substrate; forming a piezoelectric stacked layer-structure on the first substrate; forming a sacrificial layer covering the piezoelectric stacked layer-structure on a working region; providing a second substrate; forming an adhesive layer on the second substrate; attaching a second back surface of the adhesive layer to the sacrificial layer and the piezoelectric stacked layer-structure exposed by the sacrificial layer, where the adhesive layer covers sidewalls of the sacrificial layer and is filled between the second substrate and the piezoelectric stacked layer-structure; removing the first substrate to expose a first front surface of the piezoelectric stacked layer-structure; forming release holes passing through the piezoelectric stacked layer-structure, or forming release holes passing through the second substrate; and removing the sacrificial layer through the release holes to form a cavity.