Microelectromechanical gyroscope with detection of angular velocity along a vertical axis

1 . A microelectromechanical gyroscope, comprising:

a detection structure having a substrate with a top surface parallel to a horizontal plane; and

a movable structure, suspended above the substrate and configured to perform, as a function of an angular velocity around a vertical axis, orthogonal to the horizontal plane, a sense movement along a first horizontal axis of the horizontal plane, in the presence of a drive movement along a second horizontal axis of the horizontal plane, orthogonal to the first horizontal axis the movable structure includes:

at least one drive mass internally defining a window and elastically coupled to a rotor anchor, integral with the substrate at an anchoring area, through elastic anchoring elements;

at least one bridge element, rigid and of a conductive material, cantilevered suspended with respect to the substrate and extending within the window, elastically coupled to the drive mass; and

movable electrodes, integrally carried by the bridge element within the window;

wherein the detection structure further comprises stator electrodes, arranged in the window in an interdigitated configuration with the movable electrodes, the stator electrodes being arranged below the bridge element, at a certain separation distance from the bridge element, which extends longitudinally above the stator electrodes;

wherein the detection structure further comprises a first and a second stator elements, arranged within the window, on opposite sides with respect to the bridge element, in suspended configuration above the substrate and integrally coupled to the substrate through a respective first and second stator anchors arranged at the anchoring area, in proximity of the rotor anchor; the first and second stator elements carrying first, respectively second, electrodes of the stator electrodes.

2 . The gyroscope according to claim 1 , wherein each of the first and second stator elements comprises a first portion that carries the first, respectively, second stator electrodes; and a second portion, arranged at the anchoring area, which couples the first portion to the respective first, respectively second, stator anchors.

3 . The gyroscope according to claim 1 , wherein the stator anchors are arranged at a recess formed laterally in a rotor anchoring structure, so as to be in proximity to each other and to the rotor anchor.

4 . The gyroscope according to claim 1 , wherein the first stator electrode is arranged facing the respective movable electrodes on a first side with respect to the first horizontal axis; and the second stator electrode is arranged facing the movable electrodes on a second side with respect to the first horizontal axis, at a same relative separation distance at rest, in the absence of the angular velocity.

5 . The gyroscope according to claim 1 , wherein the anchoring area is arranged centrally with respect to the window in the direction of the second horizontal axis.

6 . The gyroscope according to claim 5 , wherein the bridge element is arranged centrally to the window with respect to the second horizontal axis and is elastically coupled to the drive mass at a first longitudinal end portion thereof along the first horizontal axis; and wherein the rotor anchor is arranged at a certain separation distance from a second longitudinal end portion of the bridge element along the first horizontal axis, opposite to the first end portion.

7 . The gyroscope according to claim 1 , comprising a first and a second structural layers, superimposed on each other and arranged above the substrate; wherein the bridge element is formed in the second structural layer, arranged at a greater distance with respect to the front surface of the substrate; and the stator electrodes are formed in the first structural layer, arranged at a smaller distance with respect to the front surface of the substrate.

8 . The gyroscope according to claim 7 , wherein the drive mass and the movable electrodes are formed in both the first and second structural layers.

9 . The gyroscope according to claim 7 , wherein the first and second structural layers are epitaxial silicon layers arranged above the top surface of the substrate.

10 . A device, comprising:

a microelectromechanical gyroscope that includes:

a substrate;

a movable structure, suspended above the substrate, the movable structure includes:

a rotor anchor, integral with the substrate at an anchoring area;

at least one drive mass having a window and coupled to the rotor anchor;

at least one bridge element, cantilevered suspended with respect to the substrate and extending within the window; and

movable electrodes carried by the bridge element within the window; and

a detection structure on the substrate with a top surface, the detection structure includes:

stator electrodes, in the window in an interdigitated configuration with the movable electrodes, the stator electrodes being below the bridge element, at a certain separation distance from the bridge element, which extends longitudinally above the stator electrodes;

wherein the detection structure comprises a first and a second stator elements, arranged within the window, on opposite sides with respect to the bridge element, in suspended configuration above the substrate and integrally coupled to the substrate through a respective first and second stator anchors arranged at the anchoring area, in proximity of the rotor anchor; the first and second stator elements carrying first, respectively second, electrodes of the stator electrodes.

11 . The device of claim 10 , wherein the bridge element is elastically coupled to the drive mass through an elastic coupling element.

12 . The gyroscope according to claim 11 , wherein the bridge element is configured so as to make the bridge element integral with the drive mass during a corresponding drive movement along a second horizontal axis and also so as to allow a sense movement of the same bridge element along a first horizontal axis, in the presence of an angular velocity around a vertical axis, the sense movement of the bridge element is decoupled and independent with respect to the drive movement of the drive mass.

13 . The gyroscope according to claim 10 , wherein the stator electrodes are coupled to the movable electrodes in a fully double-differential configuration.

14 . The gyroscope according to claim 10 , wherein the detection structure has a centrally symmetrical configuration with respect to a first and second horizontal axes, with two halves specular with respect to a median axis parallel to the second horizontal axis and centrally traversing the rotor anchor, each of the two halves having a respective drive mass and a respective bridge element; wherein the respective drive masses of the two halves are configured so as to be actuated in opposite directions in a direction parallel to the second horizontal axis to cause a corresponding sense movement of the respective bridge elements.

15 . An electronic device, comprising:

a microelectromechanical gyroscope that includes:

a detection structure having a substrate with a top surface parallel to a horizontal plane; and

a movable structure, suspended above the substrate and configured to perform, as a function of an angular velocity around a vertical axis, orthogonal to the horizontal plane, a sense movement along a first horizontal axis of the horizontal plane, in the presence of a drive movement along a second horizontal axis of the horizontal plane, orthogonal to the first horizontal axis the movable structure includes:

at least one drive mass internally defining a window and elastically coupled to a rotor anchor, integral with the substrate at an anchoring area, through elastic anchoring elements;

at least one bridge element, rigid and of a conductive material, cantilevered suspended with respect to the substrate and extending within the window, elastically coupled to the drive mass; and

movable electrodes, integrally carried by the bridge element within the window; and

wherein the detection structure further comprises stator electrodes, arranged in the window in an interdigitated configuration with the movable electrodes, the stator electrodes being arranged below the bridge element, at a certain separation distance from the bridge element, which extends longitudinally above the stator electrodes;

wherein the detection structure further comprises a first and a second stator elements, arranged within the window, on opposite sides with respect to the bridge element, in suspended configuration above the substrate and integrally coupled to the substrate through a respective first and second stator anchors arranged at the anchoring area, in proximity of the rotor anchor; the first and second stator elements carrying first, respectively second, electrodes of the stator electrodes.

16 . The electronic device of claim 15 , wherein each of the first and second stator elements comprises a first portion that carries the first, respectively, second stator electrodes; and a second portion, arranged at the anchoring area, which couples the first portion to the respective first, respectively second, stator anchors.