A micromechanical rotation rate sensor system and a corresponding manufacturing method are described. The micromechanical rotation rate sensor system includes a first rotation rate sensor unit drivable rotatorily about a first axis in an oscillating manner for detecting a first outside rotation rate about a second axis and a second outside rotation rate about a third axis, the first, second and third axes being situated perpendicularly to one another, and a second rotation rate sensor unit linearly drivable by a drive unit along the second axis in an oscillating manner for detecting a third outside rotation rate about the first axis. The second rotation rate sensor unit is connected to the first rotation rate sensor unit via a first coupling unit for driving the first rotation rate sensor unit by the drive unit.

A micromechanical rotation rate sensor system and a corresponding manufacturing method are described. The micromechanical rotation rate sensor system includes a first rotation rate sensor unit drivable rotatorily about a first axis in an oscillating manner for detecting a first outside rotation rate about a second axis and a second outside rotation rate about a third axis, the first, second and third axes being situated perpendicularly to one another, and a second rotation rate sensor unit linearly drivable by a drive unit along the second axis in an oscillating manner for detecting a third outside rotation rate about the first axis. The second rotation rate sensor unit is connected to the first rotation rate sensor unit via a first coupling unit for driving the first rotation rate sensor unit by the drive unit.

A sensing device includes an anchor having a central axis that defines a first radial direction and a second radial direction, and a resonant member flexibly supported by the anchor that includes a main body made of a single-crystal solid. The main body has a first material stiffness in the first radial direction and a second material stiffness in the second radial direction that is less than the first material stiffness. Moreover, the main body has a first component stiffness in the first radial direction and a second component stiffness in the second radial direction that is substantially similar to the first component stiffness. Another sensing device includes a resonant member having a main body that defines an aperture extending through the main body, and an electrode located in the aperture such that a capacitive channel is defined between the electrode and the main body that circumscribes the electrode.

Microelectromechanical system (MEMS) inertial sensors exhibiting reduced parasitic capacitance are described. The reduction in the parasitic capacitance may be achieved by forming localized regions of thick dielectric material. These localized regions may be formed inside trenches. Formation of trenches enables an increase in the vertical separation between a sense capacitor and the substrate, thereby reducing the parasitic capacitance in this region. The stationary electrode of the sense capacitor may be placed between the proof mass and the trench. The trench may be filled with a dielectric material. Part of the trench may be filled with air, in some circumstances, thereby further reducing the parasitic capacitance. These MEMS inertial sensors may serve, among other types of inertial sensors, as accelerometers and/or gyroscopes. Fabrication of these trenches may involve lateral oxidation, whereby columns of semiconductor material are oxidized.

Microelectromechanical system (MEMS) inertial sensors exhibiting reduced parasitic capacitance are described. The reduction in the parasitic capacitance may be achieved by forming localized regions of thick dielectric material. These localized regions may be formed inside trenches. Formation of trenches enables an increase in the vertical separation between a sense capacitor and the substrate, thereby reducing the parasitic capacitance in this region. The stationary electrode of the sense capacitor may be placed between the proof mass and the trench. The trench may be filled with a dielectric material. Part of the trench may be filled with air, in some circumstances, thereby further reducing the parasitic capacitance. These MEMS inertial sensors may serve, among other types of inertial sensors, as accelerometers and/or gyroscopes. Fabrication of these trenches may involve lateral oxidation, whereby columns of semiconductor material are oxidized.

The MEMS gyroscope has a mobile mass carried by a supporting structure to move in a driving direction and in a first sensing direction, perpendicular to each other. A driving structure governs movement of the mobile mass in the driving direction at a driving frequency. A movement sensing structure is coupled to the mobile mass and detects the movement of the mobile mass in the sensing direction. A quadrature-injection structure is coupled to the mobile mass and causes a first and a second movement of the mobile mass in the sensing direction in a first calibration half-period and, respectively, a second calibration half-period. The movement-sensing structure supplies a sensing signal having an amplitude switching between a first and a second value that depend upon the movement of the mobile mass as a result of an external angular velocity and of the first and second quadrature movements. The first and second values of the sensing signal are subtracted from each other and compared with a stored difference value to supply information of variation of the scale factor.

The MEMS gyroscope has a mobile mass carried by a supporting structure to move in a driving direction and in a first sensing direction, perpendicular to each other. A driving structure governs movement of the mobile mass in the driving direction at a driving frequency. A movement sensing structure is coupled to the mobile mass and detects the movement of the mobile mass in the sensing direction. A quadrature-injection structure is coupled to the mobile mass and causes a first and a second movement of the mobile mass in the sensing direction in a first calibration half-period and, respectively, a second calibration half-period. The movement-sensing structure supplies a sensing signal having an amplitude switching between a first and a second value that depend upon the movement of the mobile mass as a result of an external angular velocity and of the first and second quadrature movements. The first and second values of the sensing signal are subtracted from each other and compared with a stored difference value to supply information of variation of the scale factor.

A method of tuning a vibratory gyroscope, the method comprising the steps of: a) applying an AC drive signal to the drive electrode, the drive signal comprising a plurality of frequencies; b) sensing the response of the resonator to the drive signal at the first and second sense electrodes; c) determining a frequency of maximum response for the first mode of vibration, and determining a frequency of maximum response for the second mode of vibration; d) deriving a comparison result from a comparison of the frequency of maximum response for the first mode of vibration with the frequency of maximum response for the second mode of vibration; and e) applying a biasing voltage to one or more of the tuning electrodes dependent on the comparison result.

A method of tuning a vibratory gyroscope, the method comprising the steps of: a) applying an AC drive signal to the drive electrode, the drive signal comprising a plurality of frequencies; b) sensing the response of the resonator to the drive signal at the first and second sense electrodes; c) determining a frequency of maximum response for the first mode of vibration, and determining a frequency of maximum response for the second mode of vibration; d) deriving a comparison result from a comparison of the frequency of maximum response for the first mode of vibration with the frequency of maximum response for the second mode of vibration; and e) applying a biasing voltage to one or more of the tuning electrodes dependent on the comparison result.

A sensing device includes a resonant member that is movable in a first mode and a second mode, and an electrode. The resonant member has a capacitive surface portion that faces and is capacitively coupled to a capacitive surface portion of the electrode. Displacement for each point along the capacitive surface portion of the resonant member in the first mode is substantially tangent to the point.