Capacitive micromachined accelerometer and manufacturing method thereof

Abstract

The invention discloses a capacitive micro mechanical accelerometer and a manufacturing method thereof, and belongs to the technical field of micro mechanical sensors. The accelerometer comprises a silicon chip base, an insulating layer formed on the silicon chip base, a capacitance detecting layer deposited on the insulating layer and a polycrystalline silicon movable structure shielding layer, wherein the polycrystalline silicon movable structure shielding layer is suspended in the air through the supporting from the capacitance detecting layer; a mass block in the polycrystalline silicon movable structure shielding layer drives a supporting beam to shift under the action of acceleration; an electric field line between capacitance detecting pole plates can be changed, and the capacitance variation value obtained through the variation of the electric field line is the measured acceleration information. The capacitive micro mechanical accelerometer designed by utilizing the fringe field effect has high sensitivity under wide range, and can be used for detecting the capacitance under the action of incentive capacitance and external incentive voltage, so that the accelerometer has the self-detecting function and avoids adsorption failure.

Description

technical field [0001] The invention discloses a capacitive micro-mechanical accelerometer and a manufacturing method thereof, in particular to a capacitive micro-mechanical accelerometer based on fringe electric field effects and a manufacturing method thereof, belonging to the technical field of micro-mechanical sensors. Background technique [0002] Micromachined accelerometers are one of the most successful devices in microelectromechanical systems. They have broad application prospects in the military and civilian fields, and have huge social and economic benefits. Improving performance indicators is currently the research focus in the field of micromachined accelerometers. . [0003] The capacitive micromechanical accelerometer acts on the mass block through acceleration, the mass block drives the movement of the support beam, and the comb or plate on the mass block also moves in position accordingly. When the capacitance pair formed by the comb tooth or plate and the ...

AI Technical Summary

Problems solved by technology

Other types of micro-mechanical accelerometers have complex structures, dependence on process errors, and large shortcomings of output nonlinearity

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