An RF integrated circuit device can includes a substrate and a High Electron Mobility Transistor (HEMT) device on the substrate including a ScAlN layer configured to provide a buffer layer of the HEMT device to confine formation of a 2DEG channel region of the HEMT device. An RF piezoelectric resonator device can be on the substrate including the ScAlN layer sandwiched between a top electrode and a bottom electrode of the RF piezoelectric resonator device to provide a piezoelectric resonator for the RF piezoelectric resonator device.

There are provided a piezoelectric film-attached substrate and piezoelectric element, which include, on a substrate in the following order, a lower electrode layer, a piezoelectric film containing a perovskite-type oxide containing lead as a main component of an A site, and a buffer layer, where the buffer layer contains a metal oxide represented by M.sub.dN.sub.1-dO.sub.e. Here, M consists of one or more metal elements substitutable for the A site of the perovskite-type oxide and has an electronegativity of less than 0.95. In a case of 0<d<1 and in a case where the electronegativity is denoted by X, 1.41X−1.05≤d≤A1.Math.exp(−X/t1)+y0, where A1=1.68×10.sup.12, t1=0.0306, and y0=0.59958.

There is provided a laminated substrate having a piezoelectric film, including: a substrate; and a piezoelectric film provided on the substrate interposing a base film, wherein the piezoelectric film has an alkali niobium oxide based perovskite structure represented by a composition formula of (K.sub.1-xNa.sub.x)NbO.sub.3 (0<x<1) and preferentially oriented in (001) plane direction, and a sound speed of the piezoelectric film is 5100 m/s or more.

A system for a wireless communication infrastructure using single crystal devices. The wireless system can include a controller coupled to a power source, a signal processing module, and a plurality of transceiver modules. Each of the transceiver modules includes a transmit module configured on a transmit path and a receive module configured on a receive path. The transmit modules each include at least a transmit filter having one or more filter devices, while the receive modules each include at least a receive filter. Each of these filter devices includes a single crystal acoustic resonator device formed with a thin film transfer process with at least a first electrode material, a single crystal material, and a second electrode material. Wireless infrastructures using the present single crystal technology perform better in high power density applications, enable higher out of band rejection (OOBR), and achieve higher linearity as well.

A piezoelectric device includes a base and a laminated portion. The laminated portion includes, at least above a recess, a piezoelectric layer, a pair of electrode layers to apply a voltage to the piezoelectric layer, and a membrane covering the recess. The membrane includes a piezoelectric membrane, in the piezoelectric layer, that swells on at least one of a side of the recess and a side opposite to the side of the recess.

A piezoelectric device includes a base and a laminated portion. The laminated portion includes, at least above a recess, a piezoelectric layer, a pair of electrode layers to apply a voltage to the piezoelectric layer, and a membrane covering the recess. The membrane includes a piezoelectric membrane, in the piezoelectric layer, that swells on at least one of a side of the recess and a side opposite to the side of the recess.

A piezoelectric film on a substrate is provided comprising an aluminum nitride (AlN) layer, and a Al.sub.1-x(J).sub.xN compound layer comprising a graded section with a lower (J) composition, x, adjacent to the AlN layer and a higher (J) composition, x, located away from the AlN layer, the said (J) being a singular element or a binary compound. A method for forming such a piezoelectric film is also provided. A surface acoustic wave resonator comprising such a piezoelectric film, a surface acoustic wave filter comprising such a piezoelectric film, a bulk acoustic wave resonator comprising such a piezoelectric film, and a bulk acoustic wave filter comprising such a piezoelectric film are also provided.

An ultrasound generation member according to an aspect of the present invention includes an ultrasound generation element configured to emit ultrasound in a direction of a target object in one specific container of a plurality of containers. An ultrasound emission device according to an aspect of the present invention includes the ultrasound generation member, and a drive power supply configured to apply voltage across the ultrasound generation element of the ultrasound generation member. An ultrasound emission device according to an aspect of the present invention includes the ultrasound generation member that includes, as the ultrasound generation element, a plurality of ultrasound generation elements, and a drive power supply configured to apply voltage across the plurality of ultrasound generation elements of the ultrasound generation member.

Systems and methods for operating a communication device. The methods comprise: immersing an antenna in an electric field of an incident radio wave; producing a net change in electrical charge on a surface of an electrodeformative element that acoustically vibrates when the antenna is immersed in the electric field of the incident radio wave; harvesting the electrical charge produced on the surface of the electrodeformative element to provide an antenna receive function; and providing the harvested electrical charge from the antenna to a receiver circuit of the communication device.

A multilayer structure and a piezoelectric device using the same, which have satisfactory crystal orientation even in the submicron region of the thickness of a piezoelectric layer, are provided. The multilayer structure includes a first wurtzite thin film, a first hexagonal metal layer, a first electrode layer, a second hexagonal metal layer, and a second wurtzite thin film stacked in this order. The first electrode layer is formed of a metallic material having an acoustic impedance higher than that of the second wurtzite thin film.