Stmicroelectronics S.r.l.

Stmicroelectron S.r.l.

Nicolo' Boni

Roberto Carminati

Massimiliano Merli

Enri Duqi

Marco Zamprogno

Andrea Barbieri

Luca Molinari

Lorenzo Vinciguerra

A microelectromechanical device includes a fixed structure having a frame defining a cavity, a tiltable structure elastically suspended above the cavity with main extension in a horizontal plane, a piezoelectrically driven actuation structure which can be biased to cause a desired rotation of the tiltable structure about a first and second rotation axes, and a supporting structure integral with the fixed structure and extending in the cavity starting from the frame. Lever elements are elastically coupled to the tiltable structure at a first end by elastic suspension elements and to the supporting structure at a second end by elastic connecting elements which define a lever rotation axis. The lever elements are elastically coupled to the actuation structure so that their biasing causes the desired rotation of the tiltable structure about the first and second rotation axes.

Microelectromechanical device having a structure tiltable by piezoelectric actuation about two rotation axes

A MEMS micromirror device is formed in a package including a containment body and a lid transparent to a light radiation. The package forms a cavity housing a tiltable platform having a reflecting surface. A metastructure is formed on the lid and/or on the reflecting surface and includes a plurality of diffractive optical elements.

MEMS micromirror device enveloped in a package having a transparent surface and having a tiltable platform

A MEMS device is formed by a body of semiconductor material which defines a support structure. A pass-through cavity in the body is surrounded by the support structure. A movable structure is suspended in the pass-through cavity. An elastic structure extends in the pass-through cavity between the support structure and the movable structure. The elastic structure has a first and second portions and is subject, in use, to mechanical stress. The MEMS device is further formed by a metal region, which extends on the first portion of the elastic structure, and by a buried cavity in the elastic structure. The buried cavity extends between the first and the second portions of the elastic structure.

MEMS device having an improved stress distribution and manufacturing process thereof

A MEMS device includes a semiconductor body with a cavity and forming an anchor portion, a tiltable structure elastically suspended over the cavity, first and second support arms to support the tiltable structure, and first and second piezoelectric actuation structures biasable to deform mechanically, generating a rotation of the tiltable structure around a rotation axis. The piezoelectric actuation structures carry first and second piezoelectric displacement sensors. When the tiltable structure rotates around the rotation axis, the displacement sensors are subject to respective mechanical deformations and generate respective sensing signals in phase opposition to each other, indicative of the rotation of the tiltable structure. The sensing signals are configured to be acquired in a differential manner.

MEMS device with tiltable structure and improved control

Disclosed herein is a method of making a microelectromechanical (MEMS) device. The method includes, in a single structural layer, affixing a tiltable structure to an anchorage portion with first and second supporting arms extending between the anchorage portion and opposite sides of the tiltable structure, and forming first and second resonant piezoelectric actuation structures extending between a constraint portion of the first supporting arm and the anchorage portion, on opposite sides of the first supporting arm. The method further includes coupling a handling wafer underneath the structural layer to define a cavity therebetween, and forming a passivation layer over the structural layer, the passivation layer having contact openings defined therein for routing metal regions for electrical coupling to respective electrical contact pads, the electrical contact pads being electrically connected to the first and second resonant piezoelectric actuation structures.

Resonant MEMS device having a tiltable, piezoelectrically controlled micromirror

A micro-electro-mechanical device is formed by a fixed structure having a cavity. A tiltable structure is elastically suspended over the cavity and has a main extension in a tiltable plane and is rotatable about a rotation axis parallel to the tiltable plane. A piezoelectric actuation structure includes first and second driving arms carrying respective piezoelectric material regions and extending on opposite sides of the rotation axis. The first and the second driving arms are rigidly coupled to the fixed structure and are elastically coupled to the tiltable structure. During operation, a stop structure limits movements of the tiltable structure with respect to the actuation structure along a planar direction perpendicular to the rotation axis. The stop structure has a first planar stop element formed between the first driving arm and the tiltable structure and a second planar stop element formed between the second driving arm and the tiltable structure.

Micro-electro-mechanical device with a shock-protected tiltable structure

A microelectromechanical structure includes a body of semiconductor material having a fixed frame internally defining a cavity, a mobile mass elastically suspended in the cavity and movable with a first resonant movement about a first rotation axis and with a second resonant movement about a second rotation axis, orthogonal to the first axis. First and second pairs of supporting elements, extending in cantilever fashion in the cavity, are rigidly coupled to the frame, and are piezoelectrically deformable to cause rotation of the mobile mass about the first and second rotation axes. First and second pairs of elastic-coupling elements are elastically coupled between the mobile mass and the first and the second pairs of supporting elements. The first and second movements of rotation of the mobile mass are decoupled from one another and do not interfere with one another due to the elastic-coupling elements of the first and second pairs.

Biaxial resonant microelectromechanical mirror structure with piezoelectric actuation having improved characteristics

A microelectromechanical mirror device has a fixed structure defining a cavity. A tiltable structure carrying a reflecting surface is elastically suspended above the cavity with a main extension in a horizontal plane. Elastic elements are coupled to the tiltable structure and at least one first pair of driving arms, which carry respective regions of piezoelectric material, are biasable to cause rotation of the tiltable structure about at least one first axis of rotation parallel to a first horizontal axis of the horizontal plane. The driving arms are elastically coupled to the tiltable structure on opposite sides of the first axis of rotation and are interposed between the tiltable structure and the fixed structure. The driving arms have a thickness, along an orthogonal axis transverse to the horizontal plane, smaller than a thickness of at least some of the elastic elements coupled to the tiltable structure.

Microelectromechanical mirror device with piezoelectric actuation, having an improved structure

A MEMS device is formed in a die of semiconductor material having a cavity defined therein and having an anchorage portion. A tiltable structure is elastically suspended over the cavity and has a main extension in a horizontal plane. First and second supporting arms extend between the anchorage portion and opposite sides of the tiltable structure. First and second resonant piezoelectric actuation structures are intended to be biased to thereby cause rotation of the tiltable structure about a rotation axis. The first supporting arm is formed by first and second torsion springs, which are rigid to movements out of the horizontal plane and compliant to torsion about the rotation axis and are coupled together at a constraint region. The first and second resonant piezoelectric actuation structures extend between the anchorage portion and the constraint structure, on first and second sides of the first supporting arm.

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Alzano Lombardo, Italy

Nicolo' Boni