A highly-sensitive ultrasonic transducer with good yield is provided. The ultrasonic transducer includes a cavity layer, a pair of electrodes positioned above and below the cavity layer, insulating layers disposed above and below each of the pair of electrodes, and a filled hole that penetrates, in a vertical direction, at least a portion of the insulating layers positioned above the cavity layer. When the ultrasonic transducer is viewed from above, each electrode of the pair of electrodes includes, at a position that overlaps the embedded hole, a non-electrode region where the electrodes are not formed.

A method for manufacturing a MEMS device and the MEMS device are provided. The method includes: depositing a film on at least a part of a surface of a sacrificial layer, defining at least one through hole in the thin film by machining, removing at least a part of a material covered by the thin film in the sacrificial layer, discharging the part of the material removed from the sacrificial layer from the at least one through hole to define a cavity in the sacrificial layer, and depositing a sealing layer on a surface of the thin film facing away from the sacrificial layer to seal the at least one through hole. Compared with the manufacturing method in the related art, the manufacturing method of the disclosure only requires to deposit one layer of thin film, shorten the production period, and has reliable on-site sealing capability.

A micro-device comprising: a substrate, a stationary element rigidly connected to the substrate, a first mobile element suspended from the stationary element by first retention elements and configured to move with respect to the stationary element, a second mobile element suspended from the first mobile element by second retention elements and configured to move with respect to the first mobile element and the stationary element, a first cavity, at least some of the walls of which are formed by the stationary element and in which the first mobile element is encapsulated, a second cavity positioned in the first cavity, at least some of the walls of which are formed by the first mobile element, in which the second mobile element is encapsulated and which is insulated from the first cavity.

A micro-device structure comprises a source substrate having a sacrificial layer comprising a sacrificial portion adjacent to an anchor portion, a micro-device disposed completely over the sacrificial portion, the micro-device having a top side opposite the sacrificial portion and a bottom side adjacent to the sacrificial portion and comprising an etch hole that extends through the micro-device from the top side to the bottom side, and a tether that physically connects the micro-device to the anchor portion. A micro-device structure comprises a micro-device disposed on a target substrate. Micro-devices can be any one or more of an antenna, a micro-heater, a power device, a MEMs device, and a micro-fluidic reservoir.

A piezoelectric MEMS transducer formed in a body of semiconductor material, which has a central axis and a peripheral area and comprises a plurality of beams, transverse to the central axis and having a first end, coupled to the peripheral area of the body, and a second end, facing the central axis; a membrane, transverse to the central axis and arranged underneath the plurality of beams; and a pillar, parallel to the central axis and rigid with the second end of the beams and to the membrane. The MEMS transducer further comprises a plurality of piezoelectric sensing elements arranged on the plurality of beams.

A microelectromechanical resonator device has: a main body, with a first surface and a second surface, opposite to one another along a vertical axis, and made of a first layer and a second layer, arranged on the first layer; a cap, having a respective first surface and a respective second surface, opposite to one another along the vertical axis, and coupled to the main body by bonding elements; and a piezoelectric resonator structure formed by: a mobile element, constituted by a resonator portion of the first layer, suspended in cantilever fashion with respect to an internal cavity provided in the second layer and moreover, on the opposite side, with respect to a housing cavity provided in the cap; a region of piezoelectric material, arranged on the mobile element on the first surface of the main body; and a top electrode, arranged on the region of piezoelectric material, the mobile element constituting a bottom electrode of the piezoelectric resonator structure.

A sensor includes a sensor substrate, and an upper lid substrate joined to an upper surface of the sensor substrate. The sensor substrate includes a fixed part, a deformable beam connected to the fixed part, and a weight connected to the beam. The weight is movable relative to the fixed part. The upper lid substrate includes a first part containing silicon and a second part joined to the first part and containing glass. The first part includes a projection protruding toward the sensor substrate relative to the second part. The sensor has high accuracy or high reliability.

A method of forming a monolithic integrated PMUT and CMOS with a coplanar elastic, sealing, and passivation layer in a single step without bonding and the resulting device are provided. Embodiments include providing a CMOS wafer with a metal layer; forming a dielectric over the CMOS; forming a sacrificial structure in a portion of the dielectric; forming a bottom electrode; forming a piezoelectric layer over the CMOS; forming a top electrode over portions of the bottom electrode and piezoelectric layer; forming a via through the top electrode down to the bottom electrode and a second via down to the metal layer through the top electrode; forming a second metal layer over and along sidewalls of the first and second via; removing the sacrificial structure, an open cavity formed; and forming a dielectric layer over a portion of the CMOS, the open cavity sealed and an elastic layer and passivation formed.

A preparation method for a micro-electromechanical systems (MEMS) microphone includes the steps of: providing a silicon substrate having a silicon surface; forming an enclosed cavity in the silicon substrate; forming a plurality of spaced apart acoustic holes in the silicon substrate, each acoustic hole having two openings, one of which communicating with the cavity and the other one located on the silicon surface; forming a sacrificial layer on the silicon substrate, which includes a first filling portion, a second filling portion and a shielding portion; forming a polysilicon layer on the shielding portion; forming a recess in the silicon substrate on the side away from the silicon surface; and removing the first filling portion, the second filling portion and part of the shielding portion so that the recess is brought into communication with the cavity to form a back chamber, and that the polysilicon layer, the remainder of the shielding portion and the silicon substrate together delimit a hollow chamber, the hollow chamber communicating with the opening of the plurality of acoustic holes away from the cavity, completing the MEMS microphone.

A micro-device structure comprises a source substrate having a sacrificial layer comprising a sacrificial portion adjacent to an anchor portion, a micro-device disposed completely over the sacrificial portion, the micro-device having a top side opposite the sacrificial portion and a bottom side adjacent to the sacrificial portion and comprising an etch hole that extends through the micro-device from the top side to the bottom side, and a tether that physically connects the micro-device to the anchor portion. A micro-device structure comprises a micro-device disposed on a target substrate. Micro-devices can be 10 any one or more of an antenna, a micro-heater, a power device, a MEMs device, and a micro-fluidic reservoir.