A method includes depositing a silicon layer over a first oxide layer that overlays a first silicon substrate. The method further includes depositing a second oxide layer over the silicon layer to form a composite substrate. The composite substrate is bonded to a second silicon substrate to form a micro-electro-mechanical system (MEMS) substrate. Holes within the second silicon substrate are formed by reaching the second oxide layer of the composite substrate. The method further includes removing a portion of the second oxide layer through the holes to release MEMS features. The MEMS substrate may be bonded to a CMOS substrate.

A system is disclosed for suspension of a mobile mass, such as an inertial angular sensor, including a connection device including first and second connection elements connected to each other through a connection block and deformable in bending in a mobility plane so as to enable displacements relative to the connection block, of the mobile mass connected to the first connection element, and of another element of the system connected to the second connection element such as a support or another mobile mass respectively, along two distinct directions respectively. At least one of the connection elements is formed from two springs, connecting the connection block to the mobile mass or the other element of the system respectively. The connection element thus has improved linearity properties.

The invention relates to a detection circuit for reading out at least one position signal of a micromechanical capacitive sensor having at least one oscillating element that can be excited so as to move in an oscillating manner. In particular, the invention relates to a sensor that is operated in a closed control loop by using the detection circuit according to the invention. The invention further relates to a method for operating such a sensor. During operation, a first input connection of the detection circuit (100) is connected to an output connection of the capacitive sensor (106) and an output connection of the detection circuit (100) is connected to a loop filter of a control loop (102), wherein the control loop feeds back a feedback voltage for providing a restoring force in dependence on an output voltage of the control loop (102) to a second input connection of the detection circuit (100). The detection circuit (100) comprises at least one further feedback branch (R.sub.fb, C.sub.fb), and the output voltage of the control loop (102) is modulated onto an in-phase input voltage of the detection circuit.

The invention relates to a detection circuit for reading out at least one position signal of a micromechanical capacitive sensor having at least one oscillating element that can be excited so as to move in an oscillating manner. In particular, the invention relates to a sensor that is operated in a closed control loop by using the detection circuit according to the invention. The invention further relates to a method for operating such a sensor. During operation, a first input connection of the detection circuit (100) is connected to an output connection of the capacitive sensor (106) and an output connection of the detection circuit (100) is connected to a loop filter of a control loop (102), wherein the control loop feeds back a feedback voltage for providing a restoring force in dependence on an output voltage of the control loop (102) to a second input connection of the detection circuit (100). The detection circuit (100) comprises at least one further feedback branch (R.sub.fb, C.sub.fb), and the output voltage of the control loop (102) is modulated onto an in-phase input voltage of the detection circuit.

A gyroscope includes drive electrodes that drive a drive mass at a drive frequency. A sense mass is responsive to a Coriolis force caused by rotation of the gyroscope and oscillates based on the drive frequency. Electrodes adjacent to the sense mass drive the sense mass at test frequencies. The response to the driving at the test frequencies is measured and a gyroscope failure is identified based on this response.

A gyroscope includes drive electrodes that drive a drive mass at a drive frequency. A sense mass is responsive to a Coriolis force caused by rotation of the gyroscope and oscillates based on the drive frequency. Electrodes adjacent to the sense mass drive the sense mass at test frequencies. The response to the driving at the test frequencies is measured and a gyroscope failure is identified based on this response.

According to one embodiment, a method of acquiring rotational information of a gyro sensor includes sensing a predetermined physical quantity which depends upon an amplitude of a vibration in a second direction, the vibration in the second direction being based on Coriolis force that is applied to a movable body which is vibrating in a first direction, calculating rotational information of the movable body based on the sensed predetermined physical quantity, and stopping a vibration in the first direction of the movable body after the predetermined physical quantity is sensed.

According to one embodiment, a method of acquiring rotational information of a gyro sensor includes sensing a predetermined physical quantity which depends upon an amplitude of a vibration in a second direction, the vibration in the second direction being based on Coriolis force that is applied to a movable body which is vibrating in a first direction, calculating rotational information of the movable body based on the sensed predetermined physical quantity, and stopping a vibration in the first direction of the movable body after the predetermined physical quantity is sensed.

Systems and methods are disclosed herein for multi-axis single-drive inertial devices. A multi-axis single drive inertial device can include a rotational drive configured to oscillate a plurality of accelerometer proof masses and a plurality of gyroscope proof masses about a z axis and signal processing circuitry configured for determining inertial parameters based on motion of the plurality of accelerometer proof masses and the plurality of gyroscope proof masses. The inertial parameters can include acceleration of the inertial device along an x axis perpendicular to the z axis and along a y axis perpendicular to each of the x and z axes, and rotation of the inertial device about each of the x, y, and z axes.

Systems and methods are disclosed herein for multi-axis single-drive inertial devices. A multi-axis single drive inertial device can include a rotational drive configured to oscillate a plurality of accelerometer proof masses and a plurality of gyroscope proof masses about a z axis and signal processing circuitry configured for determining inertial parameters based on motion of the plurality of accelerometer proof masses and the plurality of gyroscope proof masses. The inertial parameters can include acceleration of the inertial device along an x axis perpendicular to the z axis and along a y axis perpendicular to each of the x and z axes, and rotation of the inertial device about each of the x, y, and z axes.