An actuation structure of a MEMS electroacoustic transducer is formed in a die of semiconductor material having a monolithic body with a front surface and a rear surface extending in a horizontal plane x-y plane and defined in which are: a frame; an actuator element arranged in a central opening defined by the frame; cantilever elements, coupled at the front surface between the actuator element and the frame; and piezoelectric regions arranged on the cantilever elements and configured to be biased to cause a deformation of the cantilever elements by the piezoelectric effect. A first stopper arrangement is integrated in the die and configured to interact with the cantilever elements to limit a movement thereof in a first direction of a vertical axis orthogonal to the horizontal plane, x-y plane towards the underlying central opening.

A MEMS micromirror device includes a monolithic body of semiconductor material having a first main surface and a second main surface, with the monolithic body having an opening extending from the second main surface and including a suspended membrane of monocrystalline semiconductor material extending between the opening and the first main surface of the monolithic body. The suspended membrane includes a supporting frame and a mobile mass carried by the supporting frame and rotatable about an axis parallel to the first main surface, with the mobile mass having a width less than a width of the opening. A reflecting region extends over the mobile mass.

A MEMS device manufacturing method and a MEMS device are provided which can enhance a degree of vacuum inside an operation space and reduce the installation cost and maintenance cost of a manufacturing apparatus as well as manufacturing cost. A MEMS device includes a MEMS device wafer having an operation element formed on a Si substrate, and a CAP wafer provided to cover the MEMS device wafer to form an operation space for operably accommodating the operation element. The CAP wafer is made of silicon and includes vent holes formed to communicate with the operation space. The operation space is sealed by performing a heat treatment in a hydrogen gas atmosphere to close the vent holes by silicon surface migration of the CAP wafer with the CAP wafer and the MEMS device wafer bonded.

An annealing device may include an array of thermal heaters, each thermal heater comprising a resistive element formed into a cavity and wherein each of the thermal heaters within the array of thermal heaters are selectively activated to anneal an annealable material deposited into the cavities.

An integrated device includes: a first die; a second die coupled in a stacked way on the first die along a vertical axis; a coupling region arranged between facing surfaces of the first die and of the second die, which face one another along the vertical axis and lie in a horizontal plane orthogonal to the vertical axis, for mechanical coupling of the first and second dies; electrical-contact elements carried by the facing surfaces of the first and second dies, aligned in pairs along the vertical axis; and conductive regions arranged between the pairs of electrical-contact elements carried by the facing surfaces of the first and second dies, for their electrical coupling. Supporting elements are arranged at the facing surface of at least one of the first and second dies and elastically support respective electrical-contact elements.

A pressure sensor designed to detect a value of ambient pressure of the environment external to the pressure sensor includes: a first substrate having a buried cavity and a membrane suspended over the buried cavity; a second substrate having a recess, hermetically coupled to the first substrate so that the recess defines a sealed cavity the internal pressure value of which provides a pressure-reference value; and a channel formed at least in part in the first substrate and configured to arrange the buried cavity in communication with the environment external to the pressure sensor. The membrane undergoes deflection as a function of a difference of pressure between the pressure-reference value in the sealed cavity and the ambient-pressure value in the buried cavity.

A process for manufacturing a microelectromechanical device envisages: providing a wafer of semiconductor material; forming a buried cavity, completely contained within the wafer, and a structural layer formed by a surface portion of the wafer and suspended over the buried cavity; forming first trenches through the structural layer as far as the buried cavity, which define the suspended structure in the structural layer; filling the first trenches and the buried cavity with sacrificial material; forming a closing structure above the structural layer; removing the sacrificial material from the first trenches and from the buried cavity to release the suspended structure, the suspended structure being isolated and buried within the wafer in a buried environment formed by the first trenches and by the buried cavity.

The structure of a micro-electro-mechanical system (MEMS) thermal sensor and a method of fabricating the MEMS thermal sensor are disclosed. A method of fabricating a MEMS thermal sensor includes forming first and second sensing electrodes with first and second electrode fingers, respectively, on a substrate and forming a patterned layer with a rectangular cross-section between a pair of the first electrode fingers. The first and second electrode fingers are formed in an interdigitated configuration and suspended above the substrate. The method further includes modifying the patterned layer to have a curved cross-section between the pair of the first electrode fingers, forming a curved sensing element on the modified patterned layer to couple to the pair of the first electrode fingers, and removing the modified patterned layer.

An integrated device includes: a first die; a second die coupled in a stacked way on the first die along a vertical axis; a coupling region arranged between facing surfaces of the first die and of the second die, which face one another along the vertical axis and lie in a horizontal plane orthogonal to the vertical axis, for mechanical coupling of the first and second dies; electrical-contact elements carried by the facing surfaces of the first and second dies, aligned in pairs along the vertical axis; and conductive regions arranged between the pairs of electrical-contact elements carried by the facing surfaces of the first and second dies, for their electrical coupling. Supporting elements are arranged at the facing surface of at least one of the first and second dies and elastically support respective electrical-contact elements.

The structure of a micro-electro-mechanical system (MEMS) thermal sensor and a method of fabricating the MEMS thermal sensor are disclosed. A method of fabricating a MEMS thermal sensor includes forming first and second sensing electrodes with first and second electrode fingers, respectively, on a substrate and forming a patterned layer with a rectangular cross-section between a pair of the first electrode fingers. The first and second electrode fingers are formed in an interdigitated configuration and suspended above the substrate. The method further includes modifying the patterned layer to have a curved cross-section between the pair of the first electrode fingers, forming a curved sensing element on the modified patterned layer to couple to the pair of the first electrodes, and removing the modified patterned layer.