A substrate that includes a film-shaped member that has a first main surface and a second main surface; a first electrode that has a third main surface and a fourth main surface, the third main surface facing the second main surface of the film-shaped member, the first electrode having a first patterning region with a first part where the film-shaped member is exposed from the first electrode and a second part where the film-shaped member is not exposed from the first electrode; and an adhesive tape facing the fourth main surface of the first electrode and the second main surface of the film-shaped member such that the adhesive tape is disposed across the first part and the second part in the first patterning region.

An acoustic generator including a piezoelectric crystal, an impedance matching layer directly bonded to the crystal with Van der Waals forces.

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 method for manufacturing a film, notably monocrystalline, on a flexible sheet, comprises the following steps: providing a donor substrate, forming an embrittlement zone in the donor substrate so as to delimit the film, forming the flexible sheet by deposition over the surface of the film, and detaching the donor substrate along the embrittlement zone so as to transfer the film onto the flexible sheet.

The present invention relates to a heterostructure, in particular, a piezoelectric structure, comprising a cover layer, in particular, a layer of piezoelectric material, the material of the cover layer having a first coefficient of thermal expansion, assembled to a support substrate, the support substrate having a second coefficient of thermal expansion substantially different from the first coefficient of thermal expansion, at an interface wherein the cover layer comprises at least a recess extending from the interface into the cover layer, and its method of fabrication.

A piezoelectric device includes a piezoelectric single crystal body with a homogeneous polarization state and of which at least a portion flexurally vibrates, an upper electrode on an upper surface of the piezoelectric single crystal body, a lower electrode on a lower surface of the piezoelectric single crystal body, and a supporting substrate below the piezoelectric single crystal body. A recess extends from a lower surface of the supporting substrate toward the lower surface of the piezoelectric single crystal body.

A piezoelectric device includes a piezoelectric single crystal body with a homogeneous polarization state and of which at least a portion flexurally vibrates, an upper electrode on an upper surface of the piezoelectric single crystal body, a lower electrode on a lower surface of the piezoelectric single crystal body, and a supporting substrate below the piezoelectric single crystal body. A recess extends from a lower surface of the supporting substrate toward the lower surface of the piezoelectric single crystal body.

A process for fabricating a micro-electro-mechanical system, includes the following steps: production of a stack on the surface of a temporary substrate so as to produce a first assembly, comprising: at least depositing a piezoelectric material or a ferroelectric material to produce a layer of piezoelectric material or of ferroelectric material; producing a first bonding layer; production of a second assembly comprising at least producing a second bonding layer on the surface of a host substrate; production of at least one acoustic isolation structure in at least one of the two assemblies; production of at least one electrode level containing one or more electrodes in at least one of the two assemblies; bonding the two assemblies via the two bonding layers, before or after the production of the at least one electrode level in at least one of the two assemblies; removing the temporary substrate.

A semiconductor device may include: a substrate wafer, a bonding layer at least partially covering a front surface of the substrate wafer, a plurality of silicon pillars bonded to the front surface of the substrate wafer by the bonding layer, a single-crystal piezoelectric film having a first surface and an opposing second surface, a top electrode arranged adjacent to the first surface of the single-crystal piezoelectric film, and a bottom electrode arranged adjacent to the second surface of the single-crystal piezoelectric film. The single-crystal piezoelectric film may be supported by the plurality of silicon pillars such that the second surface of the piezoelectric film and the front surface of the substrate wafer enclose a cavity therebetween.

A semiconductor substrate with oxide single crystal heterostructures, to which a sacrificial layer, an epitaxy functional oxide thin film having a perovskite structure and a metal layer are grown on an oxide single crystal substrate, prepared another metal layer on a semiconductor substrate, and bonded the metal layer of the oxide single crystal substrate to the metal layer of the semiconductor substrate to be face each other, and separated the oxide single crystal substrate by selectively etching and removing only the sacrificial layer after the bonding.