A method and structure for single crystal acoustic electronic device. The device includes a substrate having an enhancement layer formed overlying its surface region, a support layer formed overlying the enhancement layer, and an air cavity formed through a portion of the support layer. Single crystal piezoelectric material is formed overlying the air cavity and a portion of the enhancement layer. Also, a first electrode material coupled to the backside surface region of the crystal piezoelectric material and spatially configured within the cavity. A second electrode material is formed overlying the topside of the piezoelectric material, and a dielectric layer formed overlying the second electrode material. Further, one or more shunt layers can be formed around the perimeter of a resonator region of the device to connect the piezoelectric material to the enhancement layer.

A method of forming a piezoelectric thin film includes sputtering a first surface of a substrate to provide a piezoelectric thin film comprising AlN, AlScN, AlCrN, HfMgAlN, or ZrMgAlN thereon, processing a second surface of the substrate that is opposite the first surface of the substrate to provide an exposed surface of the piezoelectric thin film from beneath the second surface of the substrate, wherein the exposed surface of the piezoelectric thin film includes a first crystalline quality portion, removing a portion of the exposed surface of the piezoelectric thin film to access a second crystalline quality portion that is covered by the first crystalline quality portion, wherein the second crystalline quality portion has a higher quality than the first crystalline quality portion and processing the second crystalline quality portion to provide an acoustic resonator device on the second crystalline quality portion.

The present application relates to a resonator and an electronic device. A high and low acoustic impedance alternating layer, a bottom temperature coefficient of frequency compensation layer, a bottom electrode layer, a piezoelectric layer, a top electrode layer and a top temperature coefficient of frequency compensation layer are sequentially stacked on a substrate by using a specific microfabrication process, to form a new resonator. The resonator can simultaneously show excellent characteristics of low loss, wide bandwidth, low temperature sensitivity and a small size through the special stack geometry, thereby having better operation reliability.

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.

An acoustic resonator is fabricated with a substrate having a substrate top surface and a piezoelectric plate having plate front and plate back surfaces. An acoustic Bragg reflector is sandwiched between the substrate top surface and the plate back surface. The reflector has a cavity with a top surface perimeter, and the acoustic Bragg reflector is configured to reflect shear acoustic waves at a resonance frequency of the acoustic resonator. The back surface is mounted on the cavity top surface perimeter except for a portion of the plate forming a diaphragm that spans the cavity. An interdigital transducer (IDT) is formed on the plate front surface such that interleaved fingers of the IDT are disposed on the diaphragm. Two or more layers of the acoustic Bragg reflector form pedestals that support the back surface of the plate opposite some or all interleaved fingers of the IDT.

A 3D integrated circuit (3D IC) chip is described. The 3D IC chip includes a die having a compound semiconductor high electron mobility transistor (HEMT) active device. The compound semiconductor HEMT active device is composed of compound semiconductor layers on a single crystal, compound semiconductor layer. The 3D IC chip also includes an acoustic device integrated in the single crystal, compound semiconductor layer. The 3D IC chip further includes a passive device integrated in back-end-of-line layers of the die on the single crystal, compound semiconductor layer.

An apparatus and method for making an acoustic filter package where the apparatus includes a base layer; a support layer disposed on the base layer; a piezoelectric structure disposed on the support layer; wherein the piezoelectric structure comprises: a piezoelectric layer; a top electrode on a top surface of the piezoelectric layer; a bottom electrode on a bottom surface of the piezoelectric layer; a contact pad coupled to the bottom electrode that extends through an opening in the piezoelectric layer and is coupled to the bottom electrode or the top electrode; and a corrosion resistant pad disposed on the contact pad; and a capping structure disposed on the piezoelectric structure.

An RF circuit device using modified lattice, lattice, and ladder circuit topologies. The devices can include four resonator devices and four shunt resonator devices. In the ladder topology, the resonator devices are connected in series from an input port to an output port while shunt resonator devices are coupled to the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a pair of resonator devices that are coupled to differential input and output ports. A pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. These topologies may be applied using single crystal or polycrystalline bulk acoustic wave (BAW) resonators.

A bulk acoustic wave (BAW) structure includes a single crystal piezoelectric material layer, a first electrode, a second electrode and an acoustic reflector. The first and second electrodes are respectively located on a first surface and a second surface of the single crystal piezoelectric material layer. The area of the second electrode is greater than or equal to that of the second surface of the single crystal piezoelectric material layer, and the contact area of the single crystal piezoelectric material layer with the second electrode is equal to the area of the second surface of the single crystal piezoelectric material layer. The acoustic reflector is disposed on a surface of the first electrode.

An electro-acoustic resonator comprises an acoustic mirror (120) disposed on a carrier substrate (110), a bottom electrode (130) and a piezoelectric layer (140). An aluminum seed layer (180) is disposed on the piezoelectric layer and a structured silicon dioxide flap layer (150) is disposed on the aluminum seed layer. The aluminum seed layer (180) increases the quality factor of the resonator and leads to enhanced RF filter performance.