A piezoelectric device includes a piezoelectric body at least a portion of which can bend and vibrate, an upper electrode on an upper surface of the piezoelectric body and in which distortion of a crystal lattice is reduced as a distance from the upper surface of the piezoelectric body increases, a lower electrode on a lower surface of the piezoelectric body and in which distortion of a crystal lattice is reduced as a distance from the upper surface of the piezoelectric body increases, and a support substrate below the piezoelectric body, in which a recess extending from a lower surface of the support substrate toward the lower surface of the piezoelectric device is provided.

A vibration generating device includes: a vibrator; and a piezoelectric actuator. The vibrator has a first main surface and a second main surface on a side opposite to the first main surface. The piezoelectric actuator is joined to the second main surface. A plurality of recessions and projections is formed at equal intervals on the first main surface. The vibration generating device is configured to be capable of presenting a haptic sensation while preventing a contact sound from being generated.

A transduction unit of a non-contact human sleep physiological parameter detection sensor includes a circuit board, a piezoelectric film and conductive adhesives, wherein the piezoelectric film includes a film sheet and two electrodes, which are respectively arranged on two side faces of the film sheet; the piezoelectric film is attached to the circuit board; and the two electrodes of the piezoelectric film are respectively electrically connected to two exposed pad electrodes on the circuit board by means of the conductive adhesives.

Provided is a composite substrate for surface acoustic wave device which does not cause peeling of an entire surface of a piezoelectric single crystal film even when heating the film to 400° C. or higher in a step after bonding. The composite substrate is formed by providing a piezoelectric single crystal substrate and a support substrate, forming a film made of an inorganic material on at least one of the piezoelectric single crystal substrate and the support substrate, and joining the piezoelectric single crystal substrate with the support substrate so as to sandwich the film made of the inorganic material.

A bonded body has a supporting substrate composed of silicon, a piezoelectric material substrate, and a bonding layer provided on a surface of the supporting substrate and composed of silicon oxide. The bonding layer has a refractive index of 1.468 or higher and 1.474 or lower.

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.

In a chip-on-array approach, acoustic and electronic modules are separately formed. The acoustic stack is connected to one interposer, and the electronics are connected to another interposer. Different connection processes (e.g., using low temperature bonding for the acoustic stack and higher temperature-based interconnect for the electronics) may be used. This arrangement may allow for different pitches of the transducer elements and the I/O of the electronics by staggering vias in the interposers. The two interposers are then connected to form the chip-on-array.

The present disclosure relates to a piezoelectric single-crystal element, a MEMS device using same, and a method for manufacturing same, wherein the piezoelectric single-crystal element includes a wafer, a lower electrode stacked on the wafer, a piezoelectric single-crystal thin film stacked on the lower electrode, and an upper electrode stacked on the piezoelectric single-crystal thin film, wherein the piezoelectric single-crystal thin film is composed of PMN-PT, PIN-PMN-PT or Mn:PIN-PMN-PT, and the piezoelectric single-crystal thin film has a polarization direction set to a <001> axis, a <011> axis or a <111> axis, and a MEMS device using same.

A piezoelectric vibrating device includes a piezoelectric layer composed of a bulk piezoelectric material, a lower electrode on a first surface of the piezoelectric layer and a supporting substrate bonded with the lower electrode.

Techniques for joining dissimilar materials in microelectronics are provided. Example techniques direct-bond dissimilar materials at an ambient room temperature, using a thin oxide, carbide, nitride, carbonitride, or oxynitride intermediary with a thickness between 100-1000 nanometers. The intermediary may comprise silicon. The dissimilar materials may have significantly different coefficients of thermal expansion (CTEs) and/or significantly different crystal-lattice unit cell geometries or dimensions, conventionally resulting in too much strain to make direct-bonding feasible. A curing period at ambient room temperature after the direct bonding of dissimilar materials allows direct bonds to strengthen by over 200%. A relatively low temperature anneal applied slowly at a rate of 1° C. temperature increase per minute, or less, further strengthens and consolidates the direct bonds. The example techniques can direct-bond lithium tantalate LiTaO.sub.3 to various conventional substrates in a process for making various novel optical and acoustic devices.