Large capacitance micro inertial sensor based on slide-film damping and manufacturing method thereof

Abstract

The invention provides a large capacitance micro inertial sensor based on slide-film damping and a manufacturing method thereof. The existing sensors have big noise, poor stability and small range and bandwidth. Silicon strip groups are symmetrically arranged at the two sides of a sensor mass block in the sensor. Sensor anchor points are arranged at the two ends of the sensor mass block. Gate electrodes are arranged in the sensor mass block. Driver mass blocks are arranged corresponding to the silicon strip groups. Fixed counter electrodes are arranged on a first substrate below the sensor mass block. The manufacturing method is characterized by firstly forming the fixed counter electrodes on the first substrate, secondly forming an electric insulation layer on the upper surface of a second substrate and forming a floating zone on the lower surface of the second substrate, thirdly bonding the two substrates and finally etching the second substrate to form the sensor. The micro inertial sensor has novel structure, high resolution and sensitivity and simple manufacturing process and is beneficial to lowering the cost and improving the yield.

Description

technical field [0001] The invention belongs to the field of micro-electromechanical technology, and relates to a micro-inertial sensor, in particular to a large-capacitance micro-inertial sensor based on synovial film damping and a manufacturing method thereof. Background technique [0002] In recent ten years, accelerometers made with micromechanical technology have been developed rapidly. Its main acceleration detection technologies include piezoresistive detection, piezoelectric detection, thermal detection, resonance detection, electromagnetic detection, light detection, tunnel current detection and capacitance detection. In addition, there are accelerometers based on other detection technologies, such as optical accelerometers, electromagnetic accelerometers, and capacitive accelerometers. The development of optical accelerometers is mainly to combine the advantages of light and micromechanics to make sensors with high electromagnetic shielding or good linearity. Amo...

AI Technical Summary

Problems solved by technology

For comb-shaped capacitive sensors processed by bulk silicon technology such as deep reactive particle etching (Deep RIE), the aspect ratio of the plate capacitance is generally less than 30:1, which limits the increase in the mass of the sensor vibrator and the Reduced plate spacing

For small-pitch plate capacitors, the pressure film air damping is relatively large, which increases the mechanical noise of the sensor

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