Quadrature bias error reduction for vibrating structure gyroscopes

A method of forming a vibrating structure angular rate sensor, comprising:

• modifying a first substrate to define a planar vibrating structure and a plurality of compliant supports, the compliant supports extending between a mount formed from the first substrate and the planar vibrating structure to support the planar vibrating structure, thereby allowing the planar vibrating structure to oscillate relative to the mount in response to an electrical excitation;
• forming a first set of transducers on the planar vibrating structure for applying an electrical excitation to the vibrating structure and for sensing motion resulting from oscillation of the planar vibrating structure, wherein the first set of transducers comprises a first set of piezoelectric electrodes formed on the surface of the planar vibrating structure;
• and
• forming a plurality of capacitive regions, fixed at a distance from the planar vibrating structure in its plane, wherein the capacitive regions form a second set of transducers for applying an electrostatic force to the planar vibrating structure to induce a change in the frequency of oscillation of the planar vibrating structure.