Piezoresistive pressure sensor and preparation method thereof

Abstract

The invention provides a piezoresistive pressure sensor and a preparation method thereof. The piezoresistive pressure sensor comprises a silicon pedestal, a silicon strain film, a glass pedestal, a pressure-sensitive resistor and a heavily-doped contact region. The silicon pedestal is provided with a cantilever type connecting part. The silicon strain film is connected with the silicon pedestal through the cantilever type connecting part. The silicon strain film is located in the surrounding region of the silicon pedestal. A gap is formed between the silicon strain film and the surrounding edge of the silicon pedestal. The pressure-sensitive resistor and the heavily-doped contact region are located on the cantilever type connecting part. A cavity is formed between the glass pedestal and the silicon strain film. The cavity is communicated with the gap. The piezoresistive pressure sensor further comprises a sealing rubber layer. The sealing rubber layer seals and blocks the gap, so that a sealed cavity is formed by the cavity and the gap. According to the above technical scheme of the invention, the problems in the prior art that the size of the piezoresistive pressure sensor is enlarged and the cost of the piezoresistive pressure sensor is increased due to the fact that the sensitivity of the piezoresistive pressure sensor is increased through increasing the transverse dimension of the silicon strain film can be solved.

Description

technical field [0001] The invention relates to the technical field of pressure sensors, and more specifically, to a piezoresistive pressure sensor and a preparation method thereof. Background technique [0002] MEMS (abbreviation for Micro Electro Mechanical System, referring to Micro Electro Mechanical System) is an emerging interdisciplinary high-tech research field. The piezoresistive pressure sensor based on MEMS technology has been widely used in emerging markets due to its excellent sensitivity, reliability and relatively low manufacturing cost. With the increasing demand, various fields put forward new requirements for piezoresistive pressure sensors based on MEMS technology: lower cost, smaller size, lower power consumption and higher sensitivity. [0003] Please refer to the attached figure 1 , figure 1 The structure of a typical piezoresistive pressure sensor is shown. figure 1 The shown piezoresistive pressure sensor includes a silicon base 11 , a silicon str...

AI Technical Summary

Problems solved by technology

[0006] The present invention provides a piezoresistive pressure sensor to solve the problem of increasing the size and cost of the piezoresistive pressure sensor caused by increasing the lateral dimension of the silicon strain film to improve the sensitivity

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