Hexagonal silicon membrane piezoresistive pressure sensor for embedded monocrystal silicon cavity and method

Abstract

The invention relates to a hexagonal silicon membrane piezoresistive pressure sensor for an embedded monocrystal silicon cavity and a method. The piezoresistive pressure sensor is characterized in that a micro-machine pressure sensor is obtained by carrying out micro-machine processing on a (111) monocrystalline silicon piece monolithic monohedron silicon; a monocrystal silicon membrane is taken as the pressure sensing membrane of the pressure sensor, the membrane is designed to be a regular hexagon, the angle between each two adjacent sides of the hexagon is 120 degrees; a pressure chamber is positioned under the membrane and is directly embedded to the inner of the silicon piece; the chamber processing respectively utilizes a strip structure way and a grid structure way, and the chamber is formed by transverse etching empty and seaming. According to stress distribution of the membrane area, the longitudinal effect and the transverse effect of piezo-resistance are utilized to respectively design two different types of piezo-resistance configuration ways. A monolithic monohedron silicon micro-machine processing technology is utilized to realize the structure processing of the sensor, and a piezoresistive element integration method is disclosed. The method can be used for manufacturing pressure sensors with the characteristics of large measuring range from 1KPa to 50MPa, high sensitivity, small size and the like, and has broad application prospects.

Description

technical field [0001] The invention relates to a hexagonal silicon diaphragm piezoresistive pressure sensor embedded in a single crystal silicon cavity and a manufacturing method thereof, belonging to the field of silicon micromechanical sensors. Background technique [0002] The piezoresistive pressure sensor appeared in the 1960s. With the continuous development of MEMS technology and the maturity of silicon micromachining technology, the sensitive components have been miniaturized, and the mass production and low cost of sensor production have been realized. The dominant position in the field of pressure measurement is much more advanced than the traditional membrane potentiometer, variable inductance, force balance, metal strain gauge, variable capacitance and semiconductor strain gauge sensors. It has a series of advantages such as high sensitivity, fast response speed, good reliability, high precision, low power consumption, and easy miniaturization and integration. ...

AI Technical Summary

Problems solved by technology

Since these thin film materials are inferior to single crystal silicon thin film materials in terms of mechanical properties, and the pressure diaphragm processed by surface micromachining cannot be too thick, it is impossible to process a large range of pressure sensors, and the internal stress of the deposited film also affects Sensor output characteristics and other issues, moreover, the surface micromachined pressure sensor is not easy to integrate piezoresistive devices on the diaphragm

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