Method of making a micromechanical silicon-on-glass tuning fork gyroscope

Abstract

A micromechanical tuning fork gyroscope fabricated by a dissolved silicon wafer process whereby electrostatic bonding forms a hermetic seal between an etched glass substrate, metal electrodes deposited thereon, and a silicon comb-drive tuning fork gyroscope. The dissolved silicon wafer process involves single sided processing of a silicon substrate, including the steps of etching recesses, diffusing an etch resistant dopant into the silicon substrate, and releasing various components of the silicon gyroscope by etching through the diffusion layer in desired locations. The glass substrate also undergoes single sided processing, including the steps of etching recesses, depositing a multi-metal system in the recesses, and selectively etching portions of the multi-metal system. One substrate is inverted over the other and aligned before anodic bonding of the two substrates is performed.