A resonance device that includes a MEMS substrate that includes a resonator, a top cover having a silicon oxide film on a surface thereof that faces the MEMS substrate, and a bonding part that bonds the MEMS substrate and the top cover to each other so as to seal a vibration space of the resonator. The silicon oxide film includes a through hole that is formed along at least part of the periphery of the vibration space when the top cover is viewed in a plan view and that penetrates to a surface of the top cover. The through hole includes a first metal layer.

An elastic wave device includes a piezoelectric substrate, an IDT electrode including a first electrode layer located on the piezoelectric substrate and including one of Mo and W as a main component and a second electrode layer laminated on the first electrode layer and including Cu as a main component, and a dielectric film located on the piezoelectric substrate and covering the IDT electrode. The piezoelectric substrate is made of lithium niobate. The dielectric film is made of silicon oxide. The elastic wave device utilizes Rayleigh waves propagating along the piezoelectric substrate.

There is provided a piezoelectric laminate, including: a substrate; and a piezoelectric film formed on the substrate, wherein the piezoelectric film is a film containing an alkali niobium oxide of a perovskite structure represented by a composition formula of (K.sub.1-xNa.sub.x)NbO.sub.3 (0<x<1), and having Young's modulus of less than 100 GPa.

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. Patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the electrodes and a planarized support layer is deposited over the sacrificial layer. The device can include temperature compensation layers (TCL) that improve the device TCF. These layers can be thin layers of oxide type materials and can be configured between the top electrode and the piezoelectric layer, between the bottom electrode and the piezoelectric layer, between two or more piezoelectric layers, and any combination thereof. In an example, the TCLs can be configured from thick passivation layers overlying the top electrode and/or underlying the bottom electrode.

A thin-film piezoelectric actuator includes: a substrate; a lower electrode laminated on the substrate; a laminated structure configured to be laminated on the lower electrode and including a plurality of thin-film piezoelectric films alternately laminated with an intermediate electrode between; an upper electrode laminated on the laminated structure; a first protective layer configured to be provided on an upper surface of the upper electrode and made of an alloy material containing iron, cobalt, and molybdenum; and a second protective layer configured to be provided at least on an upper surface of an end portion of the intermediate electrode that is not between the thin-film piezoelectric films, and made of an alloy material containing iron, cobalt, and molybdenum. The present invention provides a thin-film piezoelectric actuator that can achieve high performance and can effectively suppress the occurrence of cracks at the end portion of the piezoelectric film in the lower layer.

A method for manufacturing a hybrid structure comprising an effective layer of piezoelectric material having an effective thickness and disposed on a supporting substrate having a substrate thickness and a thermal expansion coefficient lower than that of the effective layer includes: a) a step of providing a bonded structure comprising a piezoelectric material donor substrate and the supporting substrate, b) a first step of thinning the donor substrate to form a thinned layer having an intermediate thickness and disposed on the supporting substrate, the assembly forming a thinned structure; c) a step of heat treating the thinned structure at an annealing temperature; and d) a second step, after step c), of thinning the thinned layer to form the effective layer. The method also comprises, prior to step b), a step a′) of determining a range of intermediate thicknesses that prevent the thinned structure from being damaged during step c).

A piezo electric device having a configuration that can suppress the formation of a leakage path between electrodes that sandwich a piezoelectric layer and also reduce deterioration in the piezoelectric characteristics, is provided. The piezoelectric device has a first electrode, a piezoelectric layer, and a second electrode stacked in this order on a substrate. The first electrode and the second electrode are arranged so as not to overlap each other in the stacking direction.

An acoustic wave transmitting structure and a display device are provided. The acoustic wave transmitting structure includes a first layer, a second layer, and an intermediate layer. The first layer has a first acoustic impedance Z1. The second layer has a second acoustic impedance Z2. The intermediate layer is disposed between the first layer and the second layer, and has a third acoustic impedance Z3. Z1, Z2, and Z3 satisfy a relation: (Z1+Z2)/6.8≤Z3≤(Z1+Z2)/0.6. The display device includes a display panel and an acoustic wave generator. The display panel has a substrate. A plurality of display elements are disposed on one side of the substrate. The acoustic wave generator is disposed on the other side of the substrate of the display panel through the acoustic wave transmitting structure. The other side of the substrate is opposite to the one side of the substrate.

There is provided a piezoelectric laminate including, in the following order, a lower electrode layer and a piezoelectric film containing a Pb-containing perovskite-type oxide, in which the piezoelectric film contains an oxygen atom .sup.18O having a mass number of 18 in oxygen as a constituent element in excess of a natural abundance ratio. There are also provided a piezoelectric laminate, a piezoelectric element, and a manufacturing method for a piezoelectric laminate.

A composite substrate 10 includes a first substrate 10 comprised of a piezoelectric single crystal and a second substrate 20 comprised of a silicon single crystal bonded to the first substrate 10. In the second substrate, a planar orientation is (111), and ψ of Euler angles (φ, θ, ψ) is offset from 0°. Due to this, a bulk wave spurious is reduced in a specific frequency band.