It is formed, over a supporting body made of a ceramic, a bonding layer composed of one or more material selected from the group consisting of mullite, alumina, tantalum pentoxide, titanium oxide and niobium pentoxide. Neutralized beam is irradiated onto a surface of the bonding layer to activate the surface of the bonding layer. The surface of the bonding layer and the piezoelectric single crystal substrate are bonded by direct bonding.

A bonded body includes a supporting substrate, 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 tantalite. A nitrogen concentration at an interface between the piezoelectric material substrate and silicon oxide layer is higher than a nitrogen concentration at an interface between the silicon oxide layer and the supporting substrate.

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 system for a wireless communication infrastructure using single crystal devices. The wireless system can include a controller coupled to a power source, a signal processing module, and a plurality of transceiver modules. Each of the transceiver modules includes a transmit module configured on a transmit path and a receive module configured on a receive path. The transmit modules each include at least a transmit filter having one or more filter devices, while the receive modules each include at least a receive filter. Each of these filter devices includes a single crystal acoustic resonator device formed with a thin film transfer process with at least a first electrode material, a single crystal material, and a second electrode material. Wireless infrastructures using the present single crystal technology perform better in high power density applications, enable higher out of band rejection (OOBR), and achieve higher linearity as well.

A piezoelectric resonator includes a piezoelectric thin film including a functional conductor, a fixing layer provided on a principal surface of the piezoelectric thin film to define a void that overlaps a functional portion region, and a support substrate on a principal surface of the fixing layer. A sacrificial layer is provided on a principal surface of a piezoelectric substrate and the fixing layer is provided on the principal surface of the piezoelectric substrate to cover the sacrificial layer. The support substrate is attached to a surface of the fixing layer and the piezoelectric thin film is peeled from the piezoelectric substrate. The functional conductor is provided on the piezoelectric thin film, a through hole is provided in the piezoelectric thin film to straddle a boundary between the fixing layer and the sacrificial layer, and the sacrificial layer is removed by wet etching using the through hole to form the void.

The present invention relates to a method for producing an intravascular ultrasonic transducer and a structure for same, the method for producing a ultrasonic transducer producing a single element by: forming a piezoelectric element lapped according to a previously set thickness; depositing conductive material on the lapped surface of the piezoelectric element; forming a matched layer and a rear surface layer by casting the front and rear surfaces of the piezoelectric element to which conductive material has been deposited; lapping according to a previously set thickness; and dicing the bulk material, which is a stack of a matched layer, a piezoelectric element and a rear surface layer, along the stack direction so that the size of the element is less than the critical size for intravascular ultrasound (IVUS).

A wafer level ultrasonic chip module includes a substrate, a composite layer, a conducting material, and a base material. The substrate has a through slot that passes through an upper surface of the substrate and a lower surface of the substrate. The composite layer includes an ultrasonic body and a protective layer. A lower surface of the ultrasonic body is exposed from the through slot. The protective layer covers the ultrasonic body and a partial upper surface of the substrate. The protective layer has an opening, from which a partial upper surface of the ultrasonic body is exposed. The conducting material is in contact with the upper surface of the ultrasonic body. The base material covers the through slot, such that a space is formed among the through slot, the lower surface of the ultrasonic body and an upper surface of the base material.

The invention relates to a piezoelectric device comprising flexible single crystalline piezoelectric LiNbO3 and/or LiTaO3 films integrated on flexible substrate and methods for producing the same. More specifically, the invention relates to a flexible piezoelectric device for energy harvesting. The a Flexible piezoelectric device comprises a flexible substrate layer which comprises an upper face and a lower face, and at least one LiNbO.sub.3 and/or LiTaO.sub.3 film, called LNT film bonded to one of the faces of the flexible substrate layer, wherein thickness t.sub.f of said at least one LNT film is chosen between a use range of 5 to 50 micrometers (m).

The invention relates to a piezoelectric device comprising flexible single crystalline piezoelectric LiNbO3 and/or LiTaO3 films integrated on flexible substrate and methods for producing the same. More specifically, the invention relates to a flexible piezoelectric device for energy harvesting. The a Flexible piezoelectric device comprises a flexible substrate layer which comprises an upper face and a lower face, and at least one LiNbO.sub.3 and/or LiTaO.sub.3 film, called LNT film bonded to one of the faces of the flexible substrate layer, wherein thickness t.sub.f of said at least one LNT film is chosen between a use range of 5 to 50 micrometers (m).

A manufacturing method for an ultrasonic fingerprint sensor is provided. The method may include: preparing a sintered ceramic element under incomplete sintering conditions; forming a processed ceramic element by cutting a first surface of the sintered ceramic element along a first direction in pre-designated intervals up to such a depth that leaves a remainder region at a second surface and cutting the second surface of the sintered ceramic element along a second direction perpendicular to the first direction in pre-designated intervals up to such a depth that leaves a remainder region at the first surface; sintering the processed ceramic element under complete sintering conditions; filling an insulation material into troughs formed in the processed ceramic element by the cutting processes; and polishing the first surface and second surface to remove the remainder regions such that piezoelectric rods are exposed while arranged in an array form.