A method for manufacturing a bonded substrate, the method includes: bonding a first mother substrate including a first substrate and a second mother substrate including a second substrate to form a bonded mother substrate; cutting off a part of the first mother substrate along a dividing line of the bonded mother substrate to form a cutoff portion; dividing the bonded mother substrate along the dividing line; separating a bonded substrate from the bonded mother substrate, the bonded substrate including the first substrate and the second substrate bonded to the first substrate; forming a contact terminal on an end portion of the first mother substrate, the contact terminal contactable with an external terminal; forming a communication path between the first mother substrate and the second mother substrate along the dividing line.

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.

A piezoelectric micromachined ultrasonic transducer (PMUT) device includes a layer of piezoelectric material that is activated and sensed by an electrode and a conductive plane layer. The conductive plane layer may be electrically connected to processing circuitry by a via that extends through the piezoelectric layer. One or more isolation trenches extend through the conductive plane layer to isolate the conductive plane layer from other conductive plane layers of adjacent PMUT devices of a PMUT array.

A mounting structure includes: a first substrate that has a first surface on which a functional element is provided; a wiring portion that is provided at a position, which is different from a position of the functional element on the first surface, and is conductively connected to the functional element; a second substrate that has a second surface that is opposite to the first surface; and a conduction portion that is provided on the second surface, is connected to the wiring portion, and is conductively connected the functional element. The shortest distance between the functional element and the second substrate is longer than the longest distance between the second substrate and a position where the wiring portion is connected to the conduction portion.

A method of manufacture and structure for a monolithic single chip single crystal device. The method can include forming a first single crystal epitaxial layer overlying the substrate and forming one or more second single crystal epitaxial layers overlying the first single crystal epitaxial layer. The first single crystal epitaxial layer and the one or more second single crystal epitaxial layers can be processed to form one or more active or passive device components. Through this process, the resulting device includes a monolithic epitaxial stack integrating multiple circuit functions.

A pressure sensor element and a receiving circuit are formed on an IC chip. A transmitting circuit and a piezoelectric element of an actuator are respectively formed on a transmitting chip and a piezoelectric chip. The piezoelectric chip and the pressure sensor face each other separated by a distance in an airtight first space surrounded by a package main body and a base substrate. Dielectric breakdown voltage of signal transmission from the primary side to the secondary side is set by the distance. The first space is a pressure propagation region including an insulating medium capable of transmitting vibrations of the piezoelectric element as pressure. The signal transmission is performed with high insulation by the pressure generated in the pressure propagation region between components integrated in a single module by insulating the primary side and the secondary side from each other by the insulating medium of the pressure propagation region.

Provided are an MEMS device, a head, and a liquid jet device in which substrates are inhibited from warping, so that a primary electrode and a secondary electrode can be reliably connected to each other. Included are a primary substrate 30 provided with a bump 32 including a primary electrode 34, and a secondary substrate 10 provided with a secondary electrode 91 on a bottom surface of a recessed portion 36 formed by an adhesive layer 35. The primary substrate 10 and the secondary substrate 30 are joined together with the adhesive layer 35, the primary electrode 34 is electrically connected to the secondary electrode 91 with the bump 32 inserted into the recessed portion 36, and part of the bump 32 and the adhesive layer 35 forming the recessed portion 36 overlap each other in a direction in which the bump 32 is inserted into the recessed portion 36.

A substrate for a surface acoustic wave device or bulk acoustic wave device, comprising a support substrate and an piezoelectric layer on the support substrate, wherein the support substrate comprises a semiconductor layer on a stiffening substrate having a coefficient of thermal expansion that is closer to the coefficient of thermal expansion of the material of the piezoelectric layer than that of silicon, the semiconductor layer being arranged between the piezoelectric layer and the stiffening substrate.

A substrate for a surface acoustic wave device or bulk acoustic wave device, comprising a support substrate and an piezoelectric layer on the support substrate, wherein the support substrate comprises a semiconductor layer on a stiffening substrate having a coefficient of thermal expansion that is closer to the coefficient of thermal expansion of the material of the piezoelectric layer than that of silicon, the semiconductor layer being arranged between the piezoelectric layer and the stiffening substrate.

A display device includes a touch panel; a display panel under the touch panel and displaying an image; a piezoelectric element under the touch panel and including an upper electrode, a lower electrode and a piezoelectric layer; and a rectifying circuit connected to the piezoelectric element.