Stmicroelectronics S.r.l.

Gabriele Gattere

Carlo Valzasina

Alessandro Tocchio

Francesco Rizzini

Luca Giuseppe Falorni

Federico Vercesi

Giacomo Langfelder

Luca Guerinoni

Lorenzo Corso

Manuel Riani

Giorgio Allegato

Enri Duqi

Sarah Zerbini

Dario Paci

Attilio Frangi

Valentina Zega

Andrea Opreni

Giacomo Laghi

Domenico Giusti

Roberto Carminati

Sebastiano Conti

Matteo Perletti

Silvia Adorno

Roberto Campedelli

Igor Varisco

Nicolo' Boni

Francesco Braghin

Cristian Dall'Oglio

Patrick Fedeli

Luca Lamagna

Ferruccio Resta

Damiano Milani

Jean Marie Darmanin

Alessandro Danei

Nicolo′ Manca

Giorgio Mussi

Mohammad Izadi

Micromechanical device comprising: a semiconductor body; a movable structure configured to oscillate relative to the semiconductor body along an oscillation direction; and an elastic assembly with an elastic constant, coupled to the movable structure and to the semiconductor body and configured to deform along the oscillation direction to allow the oscillation of the movable structure as a function of an acceleration applied to the micromechanical device. The movable structure and the semiconductor body comprise a control structure for the capacitive control of the oscillation of the movable structure: when the control structure is electrically controlled in a first state the micromechanical device is in a first operating mode wherein a total elastic constant of the micromechanical device has a first value, and when it is electrically controlled in a second state the micromechanical device is in a second operating mode wherein the total elastic constant has a second value lower than, or equal to, the first value.

Micromechanical device for enhanced acceleration measurement

The detection structure for a MEMS accelerometer is formed by a substrate; a first movable mass and a second movable mass which extend at a distance from each other, suspended on the substrate and which are configured to undergo a movement, with respect to the substrate, in response to an acceleration. The detection structure also has a first movable electrode integral with the first movable mass; a second movable electrode integral with the second movable mass; a first fixed electrode integral with the substrate and configured to form, with the first movable electrode, a first variable capacitor; and a second fixed electrode integral with the substrate and configured to form, with the second movable electrode, a second variable capacitor. The detection structure has an insulation region, of electrically insulating material, which is suspended on the substrate and extends between the first movable mass and the second movable mass.

Detection structure for a MEMS accelerometer having improved performances and manufacturing process thereof

A microelectromechanical sensor device has a detection structure, having: a substrate, with a top surface; an inertial mass, suspended above the top surface of the substrate and elastically coupled to a rotor anchor so as to perform an inertial movement relative to the substrate as a function of a quantity to be detected; and stator electrodes, integrally coupled to the substrate at respective stator anchors and capacitively coupled to the inertial mass so as to generate a differential capacitive variation in response to, and indicative of, the quantity to be detected. In particular, the inertial mass performs, as the inertial movement, a translation movement along a vertical axis orthogonal to the top surface of the substrate; and the stator electrodes are arranged in a suspended manner above the top surface of the substrate.

Z-axis microelectromechanical sensor device with improved stress insensitivity

The present disclosure is directed to a MEMS gyroscope formed by a substrate and a movable mass suspended on the substrate and configured to carry out a movement in a driving direction and in a detection direction perpendicular to each other. The movable mass has a first face and a second face opposite to the first face. The gyroscope also has a first and a second quadrature compensation electrode group, fixed to the substrate and capacitively coupled to the movable mass. The first quadrature compensation electrode group faces the first face of the movable mass, and the second quadrature compensation electrode group faces the second face of the movable mass. The first and the second quadrature compensation electrode groups each have a respective variable facing area on the movable mass as a result of the movement of the movable mass in the driving direction and are configured to exert an electrostatic force on the movable mass during the movement of the movable mass in the driving direction.

MEMS gyroscope having quadrature compensation electrodes and method for compensating a quadrature error

A gyroscopic sensor unit detects a phase drift between a demodulated output signal and demodulation signal during output of a quadrature test signal. A delay calculator detects the phase drift based on changes in the demodulated output signal during application of the quadrature test signal. A delay compensation circuit compensates for the phase drift by delaying the demodulation signal by the phase drift value.

Method for correcting gyroscope demodulation phase drift

MEMS actuator including: a substrate; a first and a second semiconductive layer; a frame including transverse regions formed by the second semiconductive layer, elongated parallel to a first direction and offset along a second direction, the frame being movable parallel to the second direction. The MEMS actuator includes, for each transverse region: corresponding front rotor regions, which are fixed to the transverse region and are suspended above the substrate; a first and a second stator region, which are formed by the first semiconductive layer in such a way that, when the frame is in rest position, the transverse region is laterally offset with respect to the first and the second stator regions and a first front rotor region partially faces the first stator region, and in such a way that, during a translation of the frame along the second direction, the first and/or a second front rotor region at least partially face the second stator region, when the transverse region begins to superimpose on the first stator region.

Long stroke MEMS actuator resilient to the pull-in and electronic system including the same

A MEMS actuator includes a mobile mass suspended over a substrate in a first direction and extending in a plane that defines a second direction and a third direction perpendicular thereto. Elastic elements arranged between the substrate and the mobile mass have a first compliance in a direction parallel to the first direction that is lower than a second compliance in a direction parallel to the second direction. Piezoelectric actuation structures have a portion fixed with respect to the substrate and a portion that deforms in the first direction in response to an actuation voltage. Movement-transformation structures coupled to the piezoelectric actuation structures include an elastic movement-conversion structure arranged between the piezoelectric actuation structures and the mobile mass. The elastic movement-conversion structure is compliant in a plane formed by the first and second directions and has first and second principal axes of inertia transverse to the first and second directions.

MEMS actuator for in-plane movement of a mobile mass and optical module comprising the MEMS actuator

A microelectromechanical sensor device has a detection structure including: a substrate having a first surface; a mobile structure having an inertial mass suspended above the substrate at a first area of the first surface so as to perform at least one inertial movement with respect to the substrate; and a fixed structure having fixed electrodes suspended above the substrate at the first area and defining with the mobile structure a capacitive coupling to form at least one sensing capacitor. The device further includes a single monolithic mechanical-anchorage structure positioned at a second area of the first surface separate from the first area and coupled to the mobile structure, the fixed structure, and the substrate and connection elements that couple the mobile structure and the fixed structure mechanically to the single mechanical-anchorage structure.

Microelectromechanical sensor device with improved stability to stress

An inertial structure is elastically coupled through a first elastic structure to a supporting structure so as to move along a sensing axis as a function of a quantity to be detected. The inertial structure includes first and second inertial masses which are elastically coupled together by a second elastic structure to enable movement of the second inertial mass along the sensing axis. The first elastic structure has a lower elastic constant than the second elastic structure so that, in presence of the quantity to be detected, the inertial structure moves in a sensing direction until the first inertial mass stops against a stop structure and the second elastic mass can move further in the sensing direction. Once the quantity to be detected ends, the second inertial mass moves in a direction opposite to the sensing direction and detaches the first inertial mass from the stop structure.

Mems inertial sensor with high resistance to stiction

A button device includes a MEMS sensor having a MEMS strain detection structure and a deformable substrate configured to undergo deformation under the action of an external force. The MEMS strain detection structure includes a mobile element carried by the deformable substrate via at least a first and a second anchorage, the latter fixed with respect to the deformable substrate and configured to displace and generate a deformation force on the mobile element in the presence of the external force; and stator elements capacitively coupled to the mobile element. The deformation of the mobile element causes a capacitance variation between the mobile element and the stator elements. Furthermore, the MEMS sensor is configured to generate detection signals correlated to the capacitance variation.

Waterproof MEMS button device, input device comprising the MEMS button device and electronic apparatus

A MEMS inertial sensor includes a supporting structure and an inertial structure. The inertial structure includes at least one inertial mass, an elastic structure, and a stopper structure. The elastic structure is mechanically coupled to the inertial mass and to the supporting structure so as to enable a movement of the inertial mass in a direction parallel to a first direction, when the supporting structure is subjected to an acceleration parallel to the first direction. The stopper structure is fixed with respect to the supporting structure and includes at least one primary stopper element and one secondary stopper element. If the acceleration exceeds a first threshold value, the inertial mass abuts against the primary stopper element and subsequently rotates about an axis of rotation defined by the primary stopper element. If the acceleration exceeds a second threshold value, rotation of the inertial mass terminates when the inertial mass abuts against the secondary stopper element.

MEMS inertial sensor with high resilience to the phenomenon of stiction

A MEMS inclinometer includes a substrate, a first mobile mass and a sensing unit. The sensing unit includes a second mobile mass, a number of elastic elements, which are interposed between the second mobile mass and the substrate and are compliant in a direction parallel to a first axis, and a number of elastic structures, each of which is interposed between the first and second mobile masses and is compliant in a direction parallel to the first axis and to a second axis. The sensing unit further includes a fixed electrode that is fixed with respect to the substrate and a mobile electrode fixed with respect to the second mobile mass, which form a variable capacitor.

MEMS inclinometer having a reduced vibration rectification error

Embodiments of a Coriolis-force-based flow sensing device and embodiments of methods for manufacturing embodiments of the Coriolis-force-based flow sensing device, comprising the steps of: forming a driving electrode; forming, on the driving electrode, a first sacrificial region; forming, on the first sacrificial region, a first structural portion with a second sacrificial region buried therein; forming openings for selectively etching the second sacrificial region; forming, within the openings, a porous layer having pores; removing the second sacrificial region through the pores of the porous layer, forming a buried channel; growing, on the porous layer and not within the buried channel, a second structural portion that forms, with the first structural region, a structural body; selectively removing the first sacrificial region thus suspending the structural body on the driving electrode.

Method for manufacturing a silicon-based coriolis-force-based flow sensing device, coriolis-force-based flow sensing device, and system for measuring a property of a fluid

A method for manufacturing a PMUT device including a piezoelectric element located at a membrane element is provided. The method includes receiving a silicon on insulator substrate having a first silicon layer, an oxide layer, and a second silicon layer. Portions of a first surface of the second silicon layer are exposed by removing exposed side portions of the first silicon layer and corresponding portions of the oxide layer, and a central portion including the remaining portions of the first silicon layer and of the oxide layer is defined. Anchor portions for the membrane element are formed at the exposed portions of the first surface of the second silicon layer. The piezoelectric element is formed above the central portion, and the membrane element is defined by selectively removing the second layer and removing the remaining portion of the oxide from under the remaining portion of the first silicon layer.

Piezoelectric micromachined ultrasonic transducer

A closed-loop microelectromechanical accelerometer includes a substrate of semiconductor material, an out-of-plane sensing mass and feedback electrodes. The out-of-plane sensing mass, of semiconductor material, has a first side facing the supporting body and a second side opposite to the first side. The out-of-plane sensing mass is also connected to the supporting body to oscillate around a non-barycentric fulcrum axis parallel to the first side and to the second side and perpendicular to an out-of-plane sensing axis. The feedback electrodes are capacitively coupled to the sensing mass and are configured to apply opposite electrostatic forces to the sensing mass.

Closed-loop microelectromechanical accelerometer with compensation of spurious vibration modes and process for manufacturing a microelectromechanical accelerometer

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Castronno, Italy

Gabriele Gattere