A piezoelectric thin film contains a lower layer and a first piezoelectric layer stacked on the lower layer. The first piezoelectric layer contains a tetragonal crystal 1 of a perovskite-type oxide. A (001) plane of the tetragonal crystal 1 is oriented in a normal direction dn of a surface of the first piezoelectric layer. A spacing of (100) planes of the tetragonal crystal 1 is a1. A spacing of (100) planes of a crystal contained in the lower layer is aL. A lattice mismatch rate between the first piezoelectric layer and the lower layer is 100×(aL−a1)/a1. The lattice mismatch rate is 3.0 to 12.1%. A rocking curve of diffracted X-rays of the (001) plane of the tetragonal crystal 1 is measured in an out-of-plane direction of the surface of the first piezoelectric layer. A FWHM of the rocking curve is 1.9 to 5.5°.

Various embodiments may provide an electromechanical responsive film. The electromechanical responsive film may include a composition including sodium (Na), potassium (K), niobium (Nb) and oxygen (O). The composition may have a formula (Na.sub.xK.sub.y)NbO.sub.3-δ, wherein 0≤x<1, wherein 0≤y<1, and wherein 0<x+y<1. The composition may satisfy at least one condition selected from a group consisting of a first condition of (x+y+4)/2≤(3−δ)≤(x+y+5)/2 and a second condition of 0<δ<1.

Disclosed herein are IC structures, packages, and devices that include III-N transistors integrated on the same substrate or die as resonators of RF filters. An example IC structure includes a support structure (e.g., a substrate), a resonator, provided over a first portion of the support structure, and an III-N transistor, provided over a second portion of the support structure. The IC structure includes a piezoelectric material so that first and second electrodes of the resonator enclose a first portion of the piezoelectric material, while a second portion of the piezoelectric material is enclosed between the channel material of the III-N transistor and the support structure. In this manner, one or more resonators of an RF filter may be monolithically integrated with one or more III-N transistors. Such integration may reduce costs and improve performance by reducing RF losses incurred when power is routed off chip.

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.

An object of the present invention is to provide a piezoelectric element capable of improving the sound pressure particularly in a high frequency band by decreasing the impedance in a case of being used as an electroacoustic transducer or the like, and a piezoelectric speaker formed of a piezoelectric film. The object can be achieved by using a piezoelectric film in which a piezoelectric layer containing piezoelectric particles in a polymer matrix is sandwiched between electrode layers, a planar shape is a polygon, the piezoelectric film has a protruding portion protruding from a side of a polygon other that a shortest side, and the protruding portion is provided with connecting portions for connecting an external power supply and an electrode layer or identical connecting portions are provided in the vicinity of end portions on a side other than the shortest side.

An object of the present invention is to provide a piezoelectric element capable of improving the sound pressure particularly in a high frequency band by decreasing the impedance in a case of being used as an electroacoustic transducer or the like, and a piezoelectric speaker formed of a piezoelectric film. The object can be achieved by using a piezoelectric film in which a piezoelectric layer containing piezoelectric particles in a polymer matrix is sandwiched between electrode layers, a planar shape is a polygon, the piezoelectric film has a protruding portion protruding from a side of a polygon other that a shortest side, and the protruding portion is provided with connecting portions for connecting an external power supply and an electrode layer or identical connecting portions are provided in the vicinity of end portions on a side other than the shortest side.

A MEMS structure may include a substrate, a first metal layer arranged over the substrate, an aluminum nitride layer at least partially arranged over the first metal layer and a second metal layer including one or more patterns arranged over the aluminum nitride layer. The first metal layer may include an electrode area configured for external electrical connection and one or more isolated areas configured to be electrically isolated from the electrode area and further configured to be electrically isolated from external electrical connection. Each pattern of the second metal layer may be arranged to at least partially overlap with one of the isolated area(s) of the first metal 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.

A physical vapor deposition system includes a deposition chamber, a support to hold a substrate in the deposition chamber, a target in the chamber, a power supply configured to apply power to the target to generate a plasma in the chamber to sputter material from the target onto the substrate to form a piezoelectric layer on the substrate, and a controller configured to cause the power supply to alternate between deposition phases in which the power supply applies power to the target and cooling phases in which power supply does not apply power to the target. Each deposition phase lasts at least 30 seconds and each cooling phase lasts at least 30 seconds.

An integrated circuit film bulk acoustic resonator (FBAR) device having multiple resonator thicknesses is formed on a common substrate in a stacked configuration. In an embodiment, a seed layer is deposited on a substrate, and one or more multi-layer stacks are deposited on the seed layer, each multi-layer stack having a first metal layer deposited on a first sacrificial layer, and a second metal layer deposited on a second sacrificial layer. The second sacrificial layer can be removed and the resulting space is filled in with a piezoelectric material, and the first sacrificial layer can be removed to release the piezoelectric material from the substrate and suspend the piezoelectric material above the substrate. More than one multi-layer stack can be added, each having a unique resonant frequency. Thus, multiple resonator thicknesses can be achieved on a common substrate, and hence, multiple resonant frequencies on that same substrate.