Provided is a piezoelectric ceramics having a gradual change in piezoelectric constant depending on an ambient temperature. Specifically, provided is a single-piece piezoelectric ceramics including as a main component a perovskite-type metal oxide represented by a compositional formula of ABO.sub.3, wherein an A site element in the compositional formula contains Ba and M.sub.1, the M.sub.1 being formed of at least one kind selected from the group consisting of Ca and Bi, wherein a B site element in the compositional formula contains T1 and M.sub.2, the M.sub.2 being formed of at least one kind selected from the group consisting of Zr, Sn, and Hf, wherein concentrations of the M.sub.1 and the M.sub.2 change in at least one direction of the piezoelectric ceramics, and wherein increase and decrease directions of concentration changes of the M.sub.1 and the M.sub.2 are directions opposite to each other.

An elastic wave device includes a supporting substrate, a high-acoustic-velocity film stacked on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a low-acoustic-velocity film stacked on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, the piezoelectric film is stacked on the low-acoustic-velocity film, and an IDT electrode stacked on a surface of the piezoelectric film.

Various embodiments of the present disclosure are directed towards an integrated chip including a piezoelectric membrane overlying a substrate. A plurality of conductive layers is disposed within the piezoelectric membrane. The plurality of conductive layers comprises a first conductive layer over a second conductive layer. The first conductive layer comprises a first electrode and the second conductive layer comprises a second electrode. A first conductive via is disposed in the piezoelectric membrane and contacts the first electrode. A second conductive via is disposed in the piezoelectric membrane and contacts the second electrode. A sidewall of the second conductive via comprises a vertical sidewall segment overlying a slanted sidewall segment.

A method of fabricating a configurable single crystal acoustic resonator (SCAR) device integrated circuit. The method includes providing a bulk substrate structure having first and second recessed regions with a support member disposed in between. A thickness of single crystal piezo material is formed overlying the bulk substrate with an exposed backside region configured with the first recessed region and a contact region configured with the second recessed region. A first electrode with a first terminal is formed overlying an upper portion of the piezo material, while a second electrode with a second terminal is formed overlying a lower portion of the piezo material. An acoustic reflector structure and a dielectric layer are formed overlying the resulting bulk structure. The resulting device includes a plurality of single crystal acoustic resonator devices, numbered from (R1) to (RN), where N is an integer greater than 1.

A method of manufacturing an integrated circuit. This method includes forming an epitaxial material comprising single crystal piezo material overlying a surface region of a substrate to a desired thickness and forming a trench region to form an exposed portion of the surface region through a pattern provided in the epitaxial material. Also, the method includes forming a topside landing pad metal and a first electrode member overlying a portion of the epitaxial material and a second electrode member overlying the topside landing pad metal. Furthermore, the method can include processing the backside of the substrate to form a backside trench region exposing a backside of the epitaxial material and the landing pad metal and forming a backside resonator metal material overlying the backside of the epitaxial material to couple to the second electrode member overlying the topside landing pad metal.

Highly deformable heterostructures utilizing liquid metals and nanostructures that are suitable for various applications, including but not limited to stretchable electronic devices that can be worn, for example, by a human being. Such a deformable heterostructure includes a stretchable substrate, a conductive liquid metal on the substrate, and nanostructures forming a solid-liquid heterojunction with the conductive liquid metal.

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.

A relaxor-PT based piezoelectric crystal is disclosed, comprising the general formula of (Pb.sub.1-1.5xM.sub.x){[(M.sub.I,M.sub.II).sub.1-z(M.sub.I′,M.sub.II′).sub.z].sub.1-yTi.sub.y}O.sub.3, wherein: M is a rare earth cation; M.sub.I is selected from the group consisting of Mg.sup.2+, Zn.sup.2+, Yb.sup.3+, Sc.sup.3+, and In.sup.3+; M.sub.II is Nb.sup.5+; M.sub.I′ is selected from the group consisting of Mg.sup.2+, Zn.sup.2+, Yb.sup.3+, Sc.sup.3+, In.sup.3+, and Zr.sup.4; M.sub.II′ is Nb.sup.5+ or Zr.sup.4+; 0<x≤0.05; 0.02<y<0.7; and 0≤z≤1, provided that if either M.sub.I′ or M.sub.II′ is Zr.sup.4+, both M.sub.I′ and M.sub.II′ are Zr.sup.4+. A method for forming the relaxor-PT based piezoelectric crystal is disclosed, comprising pre-synthesizing precursor materials by calcining mixed oxides, mixing the precursor materials with single oxides and calcining to form a feeding material, and growing the relaxor-PT based piezoelectric crystal having the general formula of (Pb.sub.1-1.5xM.sub.x){[(M.sub.I,M.sub.II).sub.1-z(M.sub.I′,M.sub.II′).sub.z].sub.1-yTi.sub.y}O.sub.3 from the feeding material by a Bridgman method.

Provided is a polymer-based piezoelectric composite material film which has high conversion efficiency and is capable of reproducing a sound with a sufficient volume. The polymer-based piezoelectric composite material film is a film including a polymer-based piezoelectric composite material which contains piezoelectric particles in a matrix containing a polymer material, and two electrode layers which are laminated on both surfaces of the polymer-based piezoelectric composite material, in which a coefficient of variation of intensity ratio α.sub.1 of (002) plane peak intensity and (200) plane peak intensity derived from the piezoelectric particles=(002) plane peak intensity/((002) plane peak intensity+(200) plane peak intensity) in a case where the polymer-based piezoelectric composite material is evaluated by an X-ray diffraction method is less than 0.3.

Provided is an aluminum nitride film in which, aluminum nitride crystal grains containing a metal element differing from aluminum and substituting for aluminum are main crystal grains of a polycrystalline film formed of crystal grains, and a concentration of the metal element in a grain boundary between the aluminum nitride crystal grains in at least one region of first and second regions corresponding to both end portions of the polycrystalline film in a film thickness direction of the polycrystalline film is higher than a concentration of the metal element in a center region of the aluminum nitride crystal grain in the at least one region, and is higher than a concentration of the metal element in a grain boundary between the aluminum nitride crystal grains in a third region located between the first region and the second region in the film thickness direction of the polycrystalline film.