A piezoelectric micromechanical ultrasonic transducer (PMUT) includes a multilayer stack disposed on a substrate. The multilayer stack may include an anchor structure disposed over the substrate, a piezoelectric layer stack disposed over the anchor structure, and a mechanical layer disposed proximate to the piezoelectric layer stack. The piezoelectric layer stack may be disposed over a cavity. The mechanical layer may seal the cavity and, together with the piezoelectric layer stack, is supported by the anchor structure and forms a membrane over the cavity, the membrane being configured to undergo one or both of flexural motion and vibration when the PMUT receives or transmits ultrasonic signals.

A method for producing a plurality of piezoelectric ultrasound transducer elements, the method comprising providing or depositing a piezoelectric material on at least part of a surface of a sheet of substrate to form a layered member; and forming the one or more piezoelectric ultrasound transducer elements from the layered member.

Embodiments described herein include a resonant process monitor and methods of forming such a resonant process monitor. In an embodiment, the resonant process monitor includes a frame that has a first opening and a second opening. In an embodiment, a resonant body seals the first opening of the frame. In an embodiment, a first electrode on a first surface of the resonant body contacts the frame and a second electrode is on a second surface of the resonant body. Embodiments also include a back plate that seals the second opening of the frame. In an embodiment the back plate is mechanically coupled to the frame, and the resonant body, the back plate, and interior surfaces of the frame define a cavity.

Methods of designing a BAW resonator and filter and the resulting devices are provided. Embodiments include patterning a bottom electrode of a resonator; patterning a top electrode of the resonator; and intersecting areas of the top and bottom electrodes to provide an effective area of the resonator, wherein the effective area includes a closed-loop contour line including a pulse function pattern with pre-defined amplitude, period and a number of repetitions of pulses along the closed-loop contour line.

A piezoelectric element, in which a piezoelectric body, and a vibrating plate having [111]-oriented single crystal silicon as a vibrating material are laminated is provided. In addition, a manufacturing method of a piezoelectric element including: cutting out a vibrating material to be used in the vibrating plate from a [111]-oriented single crystal silicon wafer; and laminating a piezoelectric body and the vibrating plate is provided.

The present disclosure provides a method of fabricating an ultrasound transducer. A substrate having a first side and a second side opposite the first side is provided. A bottom electrode is formed over the first side of the substrate. A piezoelectric element is formed over the bottom electrode. The piezoelectric element has a chamfered sidewall. A top electrode is formed over the piezoelectric element. A step metal element is formed over a portion of the top electrode proximate to the chamfered sidewall of the piezoelectric element.

A crystal resonator includes: a crystal resonator plate; a first sealing member that covers a first excitation electrode of the crystal resonator plate; and a second sealing member that covers a second excitation electrode of the crystal resonator plate and includes a first external electrode terminal and a second external electrode terminal to be bonded to a circuit board using a flowable conductive bonding material. The second sealing member includes a second through hole and a third through hole that pass through between a first main surface and a second main surface on which the first external electrode terminal and the second external electrode terminal are formed. The second through hole and the third through hole include: respective through electrodes for conduction between electrodes formed on the first main surface and the second main surface; and respective through parts.

A MEMS device comprising a body, having a first surface and a second surface; a diaphragm cavity in the body extending from the second surface of the body; a deformable portion in the body between the first surface and the diaphragm cavity; and a piezoelectric actuator, extending on the first surface of the body, over the deformable portion. The MEMS device is characterized in that it comprises a recess structure extending in the body and delimiting a stopper portion for the deformable portion.

A piezoelectric actuator includes a substrate, a first electrode arranged on the substrate, a piezoelectric body stacked on the first electrode, a second electrode superimposed on a surface of the piezoelectric body on a side opposite to the first electrode, and a wiring connected to the first electrode. The first electrode has a connecting portion which is arranged to protrude from an end portion of the piezoelectric body and to which the wiring is connected, and a first conductive portion is provided so that the first conductive portion overlaps with the first electrode while extending over from an area overlapped with the end portion of the piezoelectric body up to the connecting portion of the first electrode.

A piezoelectric actuator includes a substrate, a first electrode arranged on the substrate, a piezoelectric body stacked on the first electrode, a second electrode superimposed on a surface of the piezoelectric body on a side opposite to the first electrode, and a wiring connected to the first electrode. The first electrode has a connecting portion which is arranged to protrude from an end portion of the piezoelectric body and to which the wiring is connected, and a first conductive portion is provided so that the first conductive portion overlaps with the first electrode while extending over from an area overlapped with the end portion of the piezoelectric body up to the connecting portion of the first electrode.