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 resonator element includes: a substrate; and an electrode that includes a first conductive layer provided on a surface of the substrate, and a second conductive layer, provided on the opposite side to the first conductive layer on the substrate side, which is disposed within an outer edge of the first conductive layer when seen in a plan view from a direction perpendicular to the surface.

A Fin Bulk Acoustic Resonator (FinBAR) includes a fin integrally fabricated on a substrate of a glass or a semiconductor, an inner electrode deposited on the fin, a piezoelectric layer disposed on the inner electrode, an outer electrode deposited on the piezoelectric layer, a first electrode and a second electrode formed on the top surface of the substrate and connected to the inner and outer electrodes respectfully. The fin is characterized with a larger height than its width. A FinBAR array including a number of the FinBARs with different fin widths sequentially located on one chip is capable of continuously filtering frequencies in UHF and SHF bands.

A vibrator device includes a vibration element including a vibration portion and a fixed portion, a supporting member to which the fixed portion is attached to support the vibration element, and a first substrate to which the supporting member is attached, the supporting member includes a attaching portion attached to the first substrate, and A1A2 is satisfied in a case where an area of a rectangular region including the fixed portion is A1 and an area of a rectangular region including the attaching portion is A2 in a plan view seen from a thickness direction of the vibration element.

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.

An AT-cut crystal element includes a vibrator and a supporting portion. The vibrator has a planar shape with an approximately rectangular shape. The supporting portion is connected to one short side of the vibrator and has a thickness thicker than a thickness of the vibrator. The AT-cut crystal element has an oscillation frequency of approximately 76 Mhz. The vibrator has a distal end portion that is an end portion on a side opposite to the supporting portion. The distal end portion is formed to have a protrusion shape toward a distal end side thereof. The vibrator has both ends formed to have a protrusion shape toward an outside direction along the short side. The vibrator has a long side dimension L and a short side dimension W. A W/L is in a range of 0.74 to 0.79 or in a range of 0.81 to 0.93.

A method for manufacturing a piezoelectric vibration element that includes preparing a piezoelectric substrate; providing a first electrode layer on a first main surface of the piezoelectric substrate; arranging a mask on a side of the first main surface of the piezoelectric substrate, the mask including a center region and a peripheral region located along a periphery of the center region; and irradiating a radiation beam through the mask toward the first main surface of the piezoelectric substrate such that a larger amount of the radiation beam passes through the peripheral region than the center region of the mask so as to remove a part of the first electrode layer to form a first excitation electrode that decreases in thickness from the center region to the peripheral region of the mask on the first main surface of the piezoelectric substrate.

A resonator element includes: a substrate; and an electrode that includes a first conductive layer provided on a surface of the substrate, and a second conductive layer, provided on the opposite side to the first conductive layer on the substrate side, which is disposed within an outer edge of the first conductive layer when seen in a plan view from a direction perpendicular to the surface.

An acoustic wave device includes: a piezoelectric substrate; electrodes sandwiching the piezoelectric substrate and exciting a thickness shear vibration in the piezoelectric substrate; and an edge region that is a region surrounding a center region of a resonance region, wherein a first region of the edge region is located on both sides of the center region in a first direction substantially parallel to a displacement direction of a thickness shear vibration, a second region of the edge region is located on both sides of the center region in a second direction substantially perpendicular to the first direction, a width of the second region is different from a width of the first region, and acoustic velocities of acoustic waves in the piezoelectric substrate in the first and second regions are less than that in the piezoelectric substrate in the center region.