An electronic device includes a first substrate and a second substrate. A side wall joins the first substrate to the second substrate. The side wall includes a first alloy layer of a first metal and a second metal bonded directly to an upper surface of the first substrate and a second alloy layer of the first metal and a third metal disposed on top of the first alloy layer and bonded directly to a lower surface of the second substrate, the second metal and the third metal being different from each other and from the first metal. An electronic circuit is disposed on the lower surface of the second substrate within a cavity defined by the lower surface of the first substrate, the upper surface of the second substrate, and the side wall.

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.

The present disclosure provides a packaging module and packaging method of a BAW resonator. The packaging method includes: bonding a BAW resonant device including a first substrate and a resonant structure provided on the first substrate to a second substrate through a bonding layer; forming through holes exposing corresponding electrical connection portions of the resonant structure at a side of the first substrate; and forming a conductive interconnection layer on inner surfaces of the through holes and on a portion of a surface of the first substrate to avoid steps of etching through holes and depositing conductive materials from the bonding layer, so that a material of the bonding layer can be selected to provide good bonding effect, which helps to reduce the process difficulty, and improves the stability of the through holes and the formed packaging module, thereby improving the performance of the BAW resonator packaging structure.

The present disclosure provides a film bulk acoustic resonator and its fabrication method. The fabrication method includes providing a first substrate, and sequentially forming a first electrode layer, a piezoelectric material layer, and a second electrode layer, on the first substrate; forming a support layer on the second electrode layer and forming a cavity with a top opening in the support layer, where the cavity passes through the support layer; providing a second substrate and bonding the second substrate with the support layer; removing the first substrate; and patterning the first electrode layer, the piezoelectric material layer, and the second electrode layer to form a first electrode, a piezoelectric layer, and a second electrode.

Disclosed is an acoustic wave resonator comprising a substrate material formed of aluminum nitride (AlN) doped with one or more of beryllium (Be), strontium (Sr), and sodium (Na) to enhance performance of the acoustic wave resonator.

The present disclosure provides a packaging method and packaging structure of an FBAR. A second cavity in a resonator cover provided includes a groove in a second substrate and a space surrounded by an elastic bonding material layer. The elastic bonding material layer bonds the resonator cover to a resonant cavity main structure, and elasticity of the elastic bonding material layer is removed after the bonding. Through holes and a conductive interconnection layer on inner surfaces of the through holes are formed on the resonator cover. Since the second cavity includes the groove in the second substrate and the space surrounded by the elastic bonding material layer, which can avoid problems that performance of the elastic bonding material layer is unstable with temperature and humidity changes when the second cavity is entirely surrounded by the elastic bonding material layer, that is, the stability of the resonator is improved.

A method of forming a film can include heating a CVD reactor chamber containing a substrate to a temperature range between about 750 degrees Centigrade and about 950 degrees Centigrade, providing a first precursor comprising Al to the CVD reactor chamber in the temperature range, providing a second precursor comprising Sc to the CVD reactor chamber in the temperature range, providing a third precursor comprising nitrogen to the CVD reactor chamber in the temperature range, and forming the film comprising ScAlN on the substrate.

A front-end module (FEM) for a 6.1 GHz Wi-Fi acoustic wave resonator RF filter circuit. The device can include a power amplifier (PA), a 6.1 GHz resonator, and a diversity switch. The device can further include a low noise amplifier (LNA). The PA is electrically coupled to an input node and can be configured to a DC power detector or an RF power detector. The resonator can be configured between the PA and the diversity switch, or between the diversity switch and an antenna. The LNA may be configured to the diversity switch or be electrically isolated from the switch. Another 6.1 GHZ resonator may be configured between the diversity switch and the LNA. In a specific example, this device integrates a 6.1 GHz PA, a 6.1 GHZ bulk acoustic wave (BAW) RF filter, a single pole two throw (SP2T) switch, and a bypassable LNA into a single device.

A method for manufacturing a micromechanical layer structure, including: providing a first protective layer patterned to have at least one opening which is filled with sacrificial layer material; depositing a functional-layer layer structure; producing a first opening in the functional-layer layer structure to at least one opening of the first protective layer, so that in at least one of the layers of the functional-layer layer structure; depositing a second protective layer so that the first opening is filled with material of the second protective layer; patterning the second protective layer and the filled first opening to have a second opening to the first protective layer, the second opening having the same or a lesser width than the first opening; removing sacrificial layer material at least in the opening of the first protective layer; and removing protective layer material at least in the second opening.

Certain aspects provide an integrated circuit (IC) including a resonator. One example IC generally includes a substrate, a first oxide region disposed above the substrate, and a resonator. The resonator may include a piezoelectric layer, a second oxide region disposed below the piezoelectric layer and bonded to the first oxide region, and a cavity in the second oxide region, wherein at least a portion of the second oxide region is below the cavity.