Capacitive MEMS gyroscope and method of making the same

Abstract

A capacitive MEMS gyroscope and a method of making the same are disclosed. The capacitive MEMS gyroscope comprises a semiconductor substrate and a suspended composite wheel. The semiconductor substrate comprises: a read-out circuitry; at least one bottom electrode disposed on top of the semiconductor substrate, centered to a rotation axis and electrically connected to the read-out circuitry; at least one contact pad disposed on the top of the semiconductor substrate, electrically to the read-out circuitry; the composite wheel, partially made of dielectric film and configured in suspension above and in parallel to the semiconductor substrate and centered to the rotation axis, comprises: at least one top electrode disposed on the composite wheel, aligned vertically with one of the bottom electrode, electrically to the read-out circuitry; at least one circumferential spring centered to the rotation axis, bridging the composite wheel and the semiconductor substrate and consisting of at least one top electrode which electrically connects the top electrode to the contact pad on the semiconductor substrate. The gyroscope of the present invention formed by depositing and photolithographically patterning has miniaturized size, low tolerance scope and high sensing accuracy, as well as low fabrication costs owing to special bulk MEMS fabrication device unnecessary.

Description

technical field [0001] Embodiments of the present invention relate to a gyroscope, in particular to a capacitive micro-electro-mechanical systems (Micro-Electro-Mechanical Systems, MEMS for short) gyroscope and a manufacturing method thereof. Background technique [0002] Typically, a MEMS gyroscope includes pairs of circumferential comb-like microstructures that include a plurality of mutually spaced but interacting fingers that form one or more capacitors that sense rotation or rotation of a carrier substrate. angular acceleration. Multiple pairs of circumferential comb-shaped microstructures are suspended on the carrier substrate. [0003] This kind of gyroscope is usually manufactured through a batch MEMS manufacturing process, which uses a deep reactive ion etching (Deep Reactive Ion Etch, DRIE) process to etch a silicon wafer (wafer), and can usually reach hundreds of microns. etch. The batch MEMS manufacturing process limits the error range of the lateral dimension...

AI Technical Summary

Problems solved by technology

[0004] The invention provides a capacitive MEMS gyroscope and a manufacturing method thereof, which solve the problems of low sensitivity, difficulty in miniaturization and high production cost of the MEMS gyroscope manufactured by a batch MEMS manufacturing process, and provide a capacitive MEMS gyroscope and its manufacturing method. manufacturing method, high sensitivity, small size, and low production cost

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