Stmicroelectronics S.r.l.

Stmicroelectronics Gmbh

Francesco Rizzini

Gabriele Gattere

Alessandro Tocchio

Carlo Valzasina

Giacomo Langfelder

Cristian Dall'Oglio

Sarah Zerbini

Luca Guerinoni

Domenico Giusti

Federico Vercesi

Lorenzo Corso

Yamu Hu

Marco Garbarino

Davy Choi

Nicolo' Manca

Jean Marie Darmanin

Cristiano Rocco Marra

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 micro-electromechanical system (MEMS) accelerometers that are configured for a user interface mode and a true wireless stereo (TWS) mode of an audio device. The accelerometers are fabricated with specific electromechanical parameters, such as mass, stiffness, active capacitance, and bonding pressure. As a result of the specific electromechanical parameters, the accelerometers have a resonance frequency, quality factor, sensitivity, and Brownian noise density that are suitable for both the user interface mode and the TWS mode.

Dual-operating accelerometer

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 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 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

A MEMS tri-axial accelerometer is provided with a sensing structure having: a single inertial mass, with a main extension in a horizontal plane defined by a first horizontal axis and a second horizontal axis and internally defining a first window that traverses it throughout a thickness thereof along a vertical axis orthogonal to the horizontal plane; and a suspension structure, arranged within the window for elastically coupling the inertial mass to a single anchorage element, which is fixed with respect to a substrate and arranged within the window, so that the inertial mass is suspended above the substrate and is able to carry out, by the inertial effect, a first sensing movement, a second sensing movement, and a third sensing movement in respective sensing directions parallel to the first, second, and third horizontal axes following upon detection of a respective acceleration component. In particular, the suspension structure has at least one first decoupling element for decoupling at least one of the first, second, and third sensing movements from the remaining sensing movements.

MEMS tri-axial accelerometer with one or more decoupling elements

A MEMS device with teeter-totter structure includes a mobile mass having an area in a plane and a thickness in a direction perpendicular to the plane. The mobile mass is tiltable about a rotation axis extending parallel to the plane and formed by a first and by a second half-masses arranged on opposite sides of the rotation axis. The first and the second masses have a first and a second centroid, respectively, arranged at a first and a second distance b1, b2, respectively, from the rotation axis. First through openings are formed in the first half-mass and, together with the first half-mass, have a first total perimeter p1 in the plane. Second through openings are formed in the second half-mass and, together with the second half-mass, have a second total perimeter p2 in the plane, where the first and the second perimeters p1, p2 satisfy the equation: p1&#xd7;b1=p2&#xd7;b2.

MEMS device with optimized geometry for reducing the offset due to the radiometric effect

MEMs inertial sensor with high resistance to stiction

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 along 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 and one secondary stopper elements. 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.

The accelerometric sensor has a suspended region, mobile with respect to a supporting structure, and a sensing assembly coupled to the suspended region and configured to detect a movement of the suspended region with respect to the supporting structure. The suspended region has a geometry variable between at least two configurations associated with respective centroids, different from each other. The suspended region is formed by a first region rotatably anchored to the supporting structure and by a second region coupled to the first region through elastic connection elements configured to allow a relative movement of the second region with respect to the first region. A driving assembly is coupled to the second region so as to control the relative movement of the latter with respect to the first region.

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Cornaredo, Italy

Francesco Rizzini