An acoustic wave device includes a support substrate, a multilayer body, and an IDT electrode. The multilayer body includes a lithium tantalate piezoelectric layer and a lithium niobate piezoelectric layer that are laminated, and is on the support substrate. The IDT electrode is on the multilayer body, and includes electrode fingers. When a wavelength of an acoustic wave determined by a pitch of the electrode fingers is denoted as λ, a thickness of the multilayer body is about 0.66λ or less.

A bulk-acoustic wave (BAVV) resonator is provided. The BAW includes a substrate, a first electrode disposed on the substrate, a piezoelectric layer disposed to cover at least a portion of the first electrode, and a second electrode disposed to cover at least a portion of the piezoelectric layer, wherein the piezoelectric layer includes an intermediate layer, a first layer disposed above the intermediate layer and a second layer disposed below the intermediate layer, the first layer and the second layer are symmetrical in relation to a plane through which a central line of the intermediate layer passes in a thickness direction, and a thickness of the intermediate layer is greater than a thickness of each of the first and second layers.

An acoustic wave resonator package is provided. The acoustic wave resonator package includes an acoustic wave resonator including an acoustic wave generator on a first surface of a substrate; a cover disposed to face the first surface of the substrate; a bonding member disposed between the substrate and the cover, and configured to bond a bonding surface of the acoustic wave generator and the cover to each other, wherein the bonding member includes glass frit, and the bonding surface of the acoustic wave resonator which is bonded to the bonding member may be formed of a dielectric material.

A BAW resonance device comprises a first layer including a cavity located on a first side, a first electrode having a first end located in the cavity and a second end contacting with the first layer, a second layer located on the first side, and a second electrode located on the second layer above the cavity, wherein the first electrode and the second electrode are located on two sides of the second layer. The first electrode comprises a first electrode layer and a second electrode layer, and the second electrode layer and the second layer are located on two sides of the first electrode layer. The second electrode comprises a third electrode layer and a fourth electrode layer, and the second layer and the fourth electrode layer are located on two sides of the third electrode layer. Thus, the electrical resistance is lowered and the electrical losses are reduced.

A bulk acoustic wave resonator comprises a piezoelectric material layer, a first metal layer disposed on the upper surface of the piezoelectric material layer, a second metal layer disposed on the lower surface of the piezoelectric material layer, and a laterally distributed raised frame including a first raised frame disposed on the upper surface of the first metal layer and having an inner raised frame section with a tapered portion and a non-tapered portion and an outer raised frame section, and a second raised frame disposed beneath the first metal layer and the outer raised frame section, but not beneath the inner raised frame section, the inner raised frame section being laterally disposed from a central active region of the bulk acoustic wave resonator by a first distance, the outer raised frame section being laterally disposed from the central active region by a second distance greater than the first distance.

Disclosed is a film bulk acoustic resonator (FBAR) including a substrate, a lower electrode formed above the substrate, a piezoelectric layer formed above the lower electrode, an upper electrode formed above the piezoelectric layer, and a first protection layer formed above the upper electrode. Here, the first protection layer covers the upper electrode while extending downward along a side surface of one end of the upper electrode to cover a certain area of the piezoelectric layer.

A third through hole is formed in a crystal resonator plate of a crystal resonator to penetrate between a first main surface and a second main surface. A through electrode of the third through hole is conducted to a first excitation electrode. A seventh through hole is formed in a first sealing member of the crystal resonator to penetrate between a first main surface and a second main surface. The through electrode of the third through hole is conducted to the through electrode of the seventh through hole. The third through hole is not superimposed to the seventh through hole in plan view.

A method of manufacturing a bulk acoustic wave filter is provided, including: forming an acoustic reflection air cavity, a sacrificial layer, a seed layer, a lower electrode layer and a piezoelectric layer of n resonators on a substrate in sequence, wherein n is greater than or equal to 2; taking N from 1 to n for respectively repeating following steps: forming an N-th metal hard mask layer, defining an effective area of a first resonator to an N-th resonator by using a photolithography process, removing the N-th metal hard mask layer outside the effective area of the first resonator to the N-th resonator, oxidizing the piezoelectric layer outside the effective area of the first resonator to the N-th resonator to form an N-th oxidized part of the piezoelectric layer, and etching the N-th oxidized part of the piezoelectric layer; removing the metal hard mask layer of the effective area of the first resonator to the N-th resonator, so as to form the piezoelectric layer having different thicknesses of the first resonator to the N-th resonator; and forming an upper electrode layer on the piezoelectric layer having different thicknesses of the first resonator to the N-th resonator.

A BAW resonator comprises a center area (CA), an underlap region (UL) surrounding the center area having a thickness smaller than the thickness d.sub.C of the center region and a frame region (FR), surrounding the underlap region having thickness d.sub.F greater than d.sub.C.

An acoustic wave device includes first and second IDT electrodes electrically connected in series with each other by a common busbar common to the first and second IDT electrodes. In each of a first acoustic impedance layer and a second acoustic impedance layer, at least one of at least one high acoustic impedance layer and at least one low acoustic impedance layer is a conductive layer. At least a portion of the conductive layer in the first acoustic impedance layer and at least a portion of the conductive layer in the second acoustic impedance layer do not overlap with the common busbar when viewed in plan from a thickness direction of a piezoelectric layer. The conductive layer in the first acoustic impedance layer and the conductive layer in the second acoustic impedance layer are electrically insulated from each other.