A packaged resonator includes a substrate, an acoustic stack, a first polymer layer and a second polymer layer. The acoustic stack is disposed over the substrate. The first polymer layer is disposed over the substrate surrounding the acoustic stack. The first polymer layer also provides a first air gap above the acoustic stack. The second polymer layer is disposed over the acoustic stack and above the first air gap.

A bulk acoustic wave resonator includes a substrate; and a resonator including a first electrode, a piezoelectric layer, and a second electrode sequentially disposed on the substrate. Either one or both of the first electrode and the second electrode includes an alloy of molybdenum (Mo) and tantalum (Ta).

A bulk acoustic wave (BAW) resonator is disclosed. The BAW resonator includes an electrically insulating substrate, and a first electrode disposed on and in direct contact with an upper surface of the electrically insulating substrate. A second electrode is disposed over a piezoelectric layer, which is disposed over the first electrode.

A method of manufacturing an electronic device formed in a cavity may include, on a first substrate having a bottom surface and a top surface, forming a first side wall of a certain height along a periphery on the bottom surface to surround an electronic circuit disposed on the bottom surface; forming a via communicating between the bottom surface and the top surface, forming of the via including stacking a first stop layer and a second stop layer sequentially on a portion of the bottom surface of the first substrate corresponding to the via and etching the first substrate to form a through-hole corresponding to the via, a rate of etching the first substrate being greater than that of the first stop layer and a rate of etching the first stop layer being greater than that of the second stop layer; forming a second side wall of a certain height along a periphery on a top surface of the second substrate; and aligning and bonding the first side wall and the second side wall.

Methods of manufacturing an electronic device formed in a cavity may include providing a first substrate having a first side wall including a first metal formed along a periphery on a bottom surface thereof and surrounding an electronic circuit disposed on the bottom surface, providing a second substrate having a second side wall including a second metal and a third metal formed along a periphery on a top surface thereof, aligning the first substrate with the second substrate with the first side wall opposing and contacting the second side wall to internally define a cavity between the bottom surface of the first substrate, the top surface of the second substrate, the first side wall ,and the second side wall, and heating and bonding the first substrate and the second substrate by transient liquid phase bonding.

Methods of preventing water from penetrating inside a pair of bonded wafers that are bonded to one another during manufacture of an electronic device. A method is provided for manufacturing an electronic device including a first substrate having a first side wall of a certain height formed along a periphery to surround an electronic circuit disposed on a bottom surface and a second substrate having a second side wall of a certain height formed along a periphery on a top surface, the second side wall being aligned and bonded with the first side wall. The method includes forming the first side wall on a bottom surface of a first wafer as the bottom surface of the first substrate and forming a first sealing portion of a certain height along a periphery; forming the second side wall on a top surface of a second wafer as the top surface of the second substrate and forming a second sealing portion of a certain height along a periphery; and aligning and bonding the first wafer and the second wafer with each other, the first sealing portion and the first side wall being bonded with the second sealing portion and the second side wall respectively by transient liquid phase bonding.

An electronic device, such as a filter, includes a first substrate having a bottom surface and a top surface, a first side wall of a certain height being formed along a periphery of the bottom surface to surround an electronic circuit disposed on the bottom surface, an external electrode formed on the top surface, the external electrode being connected to the electronic circuit by a via communicating with the bottom surface and a second substrate. The second substrate has a second side wall of a certain height formed along a periphery of a top surface, the second side wall being aligned and bonded with the first side wall to internally form a cavity defined between the bottom surface of the first substrate, the top surface of the second substrate, the first side wall, and the second side wall.

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate and including a penetration hole penetrating therethrough; a lower electrode and an upper electrode facing each other across at least a part of the piezoelectric film; and a protective film covering an upper surface of the piezoelectric film, a side surface of the piezoelectric film, and an inner surface of the penetration hole.

A bulk acoustic wave resonator includes a substrate on which a substrate protective layer is disposed, a membrane layer forming a cavity together with the substrate, and a resonant portion disposed on the membrane layer. The cavity is formed by removing a sacrificial layer using a mixed gas obtained by mixing a halide-based gas and an oxygen gas, and at least one of the membrane layer and the substrate protective layer has a thickness difference of 170 ? or less, after the cavity is formed.

A bulk acoustic wave resonator includes a substrate protective layer disposed on a top surface of a substrate, a cavity defined by a membrane layer and the substrate, and a resonating part disposed on the membrane layer. The membrane layer includes a first layer and a second layer, the second layer having the same material as the first layer and having a density greater than that of the first layer.