A micromechanical sensor device and a corresponding production method. The micromechanical sensor device has a substrate which has a front side and a rear side. Formed on the front side, at a lateral distance, are an inertial sensor region having an inertial structure for acquiring external accelerations and/or rotations, and a pressure sensor region having a diaphragm region for acquiring an external pressure. A micromechanical function layer by which the diaphragm region is formed in the pressure sensor region. A micromechanical function layer is applied on the micromechanical function layer, the inertial structure being formed out of the second and third micromechanical function layer. A cap device encloses a first predefined reference pressure in a first cavity in the inertial sensor region, and a second cavity is formed underneath the diaphragm region.

In a non-limiting embodiment, a MEMS device may include a substrate having a device stopper. The device stopper may be integral to the substrate and formed of the substrate material. A thermal dielectric isolation layer may be arranged over the device stopper and the substrate. A device cavity may extend through the substrate and the thermal dielectric isolation layer. The thermal dielectric isolation layer and the device stopper at least partially surround the device cavity. An active device layer may be arranged over the thermal dielectric isolation layer and the device cavity.

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 includes obtaining an active device layer. The active device layer has a first surface with one or more active feature areas. First portions of the active feature areas are exposed, and second portions of the active feature areas are covered by an insulating layer. A conformal overcoat layer is formed on the first surface. A base of a microelectromechanical systems (MEMS) device layer is formed on the conformal overcoat layer. The MEMS device layer is spatially segregated from the active feature areas by removing portions of the base of the MEMS device layer in one or more antiparasitic regions (APRs) that correspond to the active feature areas. Metal MEMS features are formed on the base of the MEMS device layer. Selected portions of the active feature areas are exposed removing portions of the conformal overcoat layer that overlay the active feature areas.

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.

According to at least one embodiment, a method of fabricating a micro electro-mechanical systems (MEMS) structure is disclosed. The method involves causing an etchant to remove a portion of a sacrificial layer of the MEMS structure, the sacrificial layer between a structural layer of the MEMS structure and a substrate of the MEMS structure. In this embodiment, causing the etchant to remove the portion of the sacrificial layer involves causing a target portion of the substrate to be released from the MEMS structure. According to another embodiment, another method of fabricating a MEMS structure is disclosed. The method involves causing an etchant including water to remove a portion of a sacrificial layer of the MEMS structure, the sacrificial layer between a structural layer of the MEMS structure and a substrate of the MEMS structure. In this embodiment, the sacrificial layer and the substrate are hydrophobic.

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 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.

Microelectromechanical (MEMS) devices and associated methods are disclosed. Piezoelectric MEMS transducers (PMUTs) suitable for integration with complementary metal oxide semiconductor (CMOS) integrated circuit (IC), as well as PMUT arrays having high fill factor for fingerprint sensing, are described.

In a non-limiting embodiment, a MEMS device may include a substrate having a device stopper. The device stopper may be integral to the substrate and formed of the substrate material. A thermal dielectric isolation layer may be arranged over the device stopper and the substrate. A device cavity may extend through the substrate and the thermal dielectric isolation layer. The thermal dielectric isolation layer and the device stopper at least partially surround the device cavity. An active device layer may be arranged over the thermal dielectric isolation layer and the device cavity.