An acoustic resonator and a manufacture method thereof. The acoustic resonator includes: a substrate having cavities; piezoelectric units one by one corresponding to the cavities, the piezoelectric units cover the cavities, and each piezoelectric unit includes a first electrode layer, a piezoelectric layer and a second electrode layer sequentially stacked from bottom to top; a protective layer stacked on the piezoelectric unit; a series unit having one end electrically connected to the first electrode layer of one of the piezoelectric units, and the other end electrically connected to the second electrode layer of another one of the piezoelectric units, so as to connect the two piezoelectric units in series. Compared with the 10 related art, the piezoelectric unit is protected from further risk of damages in subsequent manufacturing processes by providing a protective layer on the piezoelectric unit, so that the acoustic resonator has better Q value and coupling coefficient.

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.

There are provided an acoustic resonator and a method of manufacturing the same. The acoustic resonator includes a resonance part including a first electrode, a second electrode, and a piezoelectric layer disposed between the first and second electrodes. The acoustic resonator also includes a substrate disposed below the resonance part and including a via hole penetrating through the substrate and a connection conductor disposed in the via hole and connected to at least one of the first and second electrodes.

The present disclosure relates to an electronic element package and a method of manufacturing the same. The electronic element package includes a substrate, an element disposed on the substrate, and a cap enclosing the element. One of the substrate and the cap includes a groove, the other of the substrate and the cap includes a protrusion engaging with the groove. A first metal layer and a second metal layer form a metallic bond with each other in a space between the groove and the protrusion.

A single-die multi-FBAR (film bulk acoustic resonator) device includes multiple FBARs having different resonant frequencies formed over a single substrate. The FBARs include piezoelectric layers having different thicknesses but with upper electrodes formed at a same height over the substrate, lower electrodes at different heights over the substrate, and different sized air gaps separating the lower electrodes from the substrate.

A bulk acoustic filter device includes: a substrate including a through hole formed by a first recess and a second recess adjacent to the first recess; a membrane layer forming a cavity with the substrate; a filter including a lower electrode disposed on the membrane layer, a piezoelectric layer disposed to cover a portion of the lower electrode, and an upper electrode formed to cover a portion of the piezoelectric layer; and an electrode connecting member disposed in the substrate, and connected to either one of the lower electrode and the upper electrode, wherein the electrode connecting member includes an insertion electrode disposed in the first recess, and a via electrode connected to the insertion electrode, and disposed on an inner peripheral surface of the second recess and a surface of the substrate.

A bulk acoustic resonator includes: a substrate including an upper surface on which a substrate protection layer is disposed; and a membrane layer forming a cavity together with the substrate, wherein a thickness deviation of either one or both of the substrate protection layer and the membrane layer is 170 or less.

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 method of fabricating an acoustic wave device includes: forming a piezoelectric thin film resonator and a second lower electrode on a substrate, the piezoelectric thin film resonator having a resonance region in which a first lower electrode and a first upper electrode face each other across a piezoelectric film, the piezoelectric film and the first upper electrode are not formed on the second lower electrode outside the resonance region; forming a first dielectric film in the resonance region and a second dielectric film on the second lower electrode outside the resonance region at a same time, the first dielectric film and the second dielectric film being made of a material different from a material of the piezoelectric film; and forming a second upper electrode on the second dielectric film, the second upper electrode facing the second lower electrode.

A bulk-acoustic wave filter device includes: a first substrate; a first filter disposed on the first substrate, within a cavity of the bulk-acoustic wave filter device; a second substrate coupled to the first substrate; a second filter disposed on the second substrate, within the cavity and facing the first filter; a first inductor layer disposed on the first substrate and around the first filter; a second inductor layer disposed on the second substrate and around the second filter, and bonded to the first inductor layer; and a sealing member sealing the cavity, together with the first and second inductor layers.