High-sensitivity pendulous micromachined silicon accelerometer and preparation method thereof

Abstract

The invention discloses a high-sensitivity pendulous micromachined silicon accelerometer and a preparation method thereof. The micromachined silicon accelerometer comprises a silicon substrate and a silicon sensitive structure which are connected into a whole; the silicon sensitive structure comprises a stress release structure, two pairs of support beams, a pair of coupling sensitive mass blocksand a pair of anchor points, the coupling sensitive mass blocks are symmetrically arranged, each coupling sensitive mass block is connected with the corresponding anchor point through one independentsupport beam and is in coupling connection with the stress release structure through the other independent support beam, and the mass center of each coupling sensitive mass block is located in the middle point of the support beam connected with the anchor point; and in the preparation method, dry etching preparation is adopted. The micromachined silicon accelerometer has the advantages that the device space utilization rate is high, the effective detection area of the sensitive mass blocks is large, the flexibility and the finished product rate are high, the cost is low, the processing qualityis high, the processing robustness is good, and the application range is wide.

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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