The present disclosure provides a method for manufacturing a semiconductor device. The method for manufacturing a semiconductor device includes the following operations. An intermediate layer is formed in the semiconductor device. A voltage is applied to the intermediate layer. A unit cell of the intermediate layer is stretched or compressed by the voltage. The polarity of the intermediate layer is changed by the voltage.

Disclosed is a method of manufacturing a piezoelectric substrate, the method including: forming an intermediate layer of Ti and a lower electrode of Pt oriented in a (111) axis direction on a substrate without heating the substrate; applying a coating liquid for forming an orientation control layer made of lead titanate onto the lower electrode; drying the coating liquid at a predetermined temperature to form an orientation control layer precursor made of lead titanate; applying a coating liquid for forming a piezoelectric thin film made of lead zirconate titanate; drying the coating liquid at a predetermined temperature to form a piezoelectric precursor made of a lead zirconate titanate precursor; and collectively firing the orientation control layer precursor and the piezoelectric precursor to crystallize both the precursors, to thereby form a piezoelectric thin film made of lead zirconate titanate preferentially oriented in a (110) plane.

There are provided a method for manufacturing a substrate excellent in heat dissipation with a small loss in radio frequencies with no need of a high temperature process in which a metal impurity is diffused, and a substrate of high thermal conductivity. A composite substrate according to the present invention is a composite substrate having a piezoelectric single crystal substrate, a support substrate, and an intermediate layer provided between the piezoelectric single crystal substrate and the support substrate. The intermediate layer is a film formed of an inorganic material, and at least a part of the film is thermally synthesized silica. The intermediate layer may be separated into at least two layers along the bonding surface of the composite substrate. The first intermediate layer in contact with the support substrate may be a layer including thermally synthesized silica.

Layer structures for RF filters can be fabricated using rare earth oxides and epitaxial aluminum nitride, and methods for growing the layer structures. A layer structure can include an epitaxial crystalline rare earth oxide (REO) layer over a substrate, a first epitaxial electrode layer over the crystalline REO layer, and an epitaxial piezoelectric layer over the first epitaxial electrode layer. The layer structure can further include a second electrode layer over the epitaxial piezoelectric layer. The first electrode layer can include an epitaxial metal. The epitaxial metal can be single-crystal. The first electrode layer can include one or more of a rare earth pnictide, and a rare earth silicide (RESi).

A method for adjusting the stress state of a piezoelectric film having a first stress state at room temperature includes a step of forming an assembly including a carrier having a thermal expansion coefficient, a compliant layer placed on the carrier, and the piezoelectric film placed on the compliant layer, the piezoelectric film having a thermal expansion coefficient different from that of the carrier. The method also includes a step of heat treating the assembly, in which the assembly is heated to a treatment temperature above the glass transition temperature of the compliant layer. The present disclosure also relates to a process for fabricating an acoustic wave device comprising the piezoelectric layer the stress state of which was adjusted as described herein.

A piezoelectric device includes at least one upper layer of piezoelectric material based on alkali metal niobate and one lower layer of metal located above a substrate, wherein it comprises a barrier layer of material that is a barrier to the diffusion of alkali metals into the metal and that is inert to the alkali metals of the niobite, the barrier material layer being located between the lower layer of metal and the upper layer of piezoelectric material. A process for producing the device is also provided.

An electronic device includes a piezoelectric module, a sensing module and a buffer element. The piezoelectric module includes a substrate and a piezoelectric element. The substrate defines an opening penetrating the substrate. The piezoelectric element is disposed on the substrate and across the opening of the substrate. The sensing module is disposed over the piezoelectric module. The buffer element is disposed between the piezoelectric module and the sensing module.

A thin-film piezoelectric material substrate includes an insulator on Si substrate and a thin-film laminated part. The insulator on Si substrate has a substrate for deposition made of silicon and an insulating layer formed on a surface of the substrate for deposition. The thin-film laminated part is formed on a top surface of the insulating layer. The thin-film laminated part has a YZ seed layer including yttrium and zirconium, and formed on the top surface; a lower electrode film laminated on the YZ seed layer; a piezoelectric material film made of lead zirconate titanate, shown by general formula Pb (Zr.sub.xTi.sub.(1-x)) O.sub.3, and formed on the lower electrode film; and an upper electrode film laminated on the piezoelectric material film.

A method of manufacture and resulting structure for a single crystal electronic device with an enhanced strain interface region. The method of manufacture can include forming a nucleation layer overlying a substrate and forming a first and second single crystal layer overlying the nucleation layer. This first and second layers can be doped by introducing one or more impurity species to form a strained single crystal layers. The first and second strained layers can be aligned along the same crystallographic direction to form a strained single crystal bi-layer having an enhanced strain interface region. Using this enhanced single crystal bi-layer to form active or passive devices results in improved physical characteristics, such as enhanced photon velocity or improved density charges.

A piezoelectric thin film is formed by adding a donor element to lead zirconate titanate. In the piezoelectric thin film, a molar ratio of lead to a total sum of zirconium and titanium is 105% or higher, and, when positive and negative coercive electric fields in polarization and electric field hysteresis are referred to as Ec (+) and Ec (?), respectively, a value of |Ec (+) |/|Ec (?) | is 0.5 or more and 1.5 or less.