A high-sensitivity torsional pendulum silicon micro-accelerometer and its preparation method

Abstract

The invention discloses a high-sensitivity torsion-type silicon micro-accelerometer and a preparation method thereof. The silicon micro-accelerometer includes a silicon substrate and a silicon sensitive structure connected as one. The silicon sensitive structure includes a stress release structure, two pairs of support beams, a pair of Coupling sensitive masses and a pair of anchor points, a pair of coupled sensitive masses are symmetrically arranged, and each coupled sensitive mass is connected to the anchor point through a separate support beam, and connected through another separate support beam It is connected and coupled with the stress release structure, and the centroid of each coupled sensitive mass is located at the midpoint of the support beam connected with the anchor point; the preparation method is prepared by dry etching. The invention has the advantages of high device space utilization rate, large effective detection area of ​​sensitive mass blocks, high sensitivity, high yield, low cost, high processing quality, good processing robustness and wide application range.

Description

technical field [0001] The invention relates to silicon microsensor technology, in particular to a high-sensitivity torsion-type silicon micro-accelerometer and a preparation method thereof. Background technique [0002] Accelerometers are mainly used to measure the motion parameters of moving objects relative to inertial space, and are indispensable sensor devices for modern life. Compared with traditional accelerometers, MEMS micro-accelerometers have the characteristics of small size, low power consumption, and easy batch processing, so they quickly become a research hotspot at home and abroad, and their performance is constantly improving, and they are widely used in military and civilian fields. [0003] At present, foreign uniaxial micro-accelerometer products have matured and been widely used. Domestic research and development of uniaxial micro-accelerometers are also increasing, and some laboratories have developed high-performance engineering. However, how to manuf...

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Problems solved by technology

However, low sensitivity, high noise, temperature characteristics and robustness are limited by its own structure

[0004] Chinese patent documents with patent application numbers 201410825011.3 and 201410606833.2 disclose two types of torsion micro-mechanical accelerometers, but the sensitive masses for micro-acceleration in the above two prior art are connected to the support beam through the cantilever beam, and the anchor points are placed outside The fixing method of the silicon sensitive structure has the problems of low device space utilization, small effective detection area of ​​the sensitive mass block, and low sensitivity; and both solutions are prepared by wet etching process, which has the problems of large device area, low yield and processing cost advanced questions

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