A kind of preparation method of resonant pressure sensor

Abstract

The invention provides a resonant pressure sensor and a manufacturing method thereof. A resonator uses a resonator structure based on an SOI silicon-based silicon comb double-ended fixed tuning fork structure. A Wheatstone bridge is formed inside the resonator by two piezoresistive materials (silicon after process doping) and two equivalent resistors (undoped silicon). The resistance change of thepiezoresistive materials is changed by a pressure change to detect the change in resonant frequency. Based on the silicon island structure, the pressure sensor structure is designed to transform thedeformation on a pressure-sensitive film into the plane vibration in the direction of the resonator through the silicon island structure, which not only reduces the mechanical coupling of the sensor,but also improves a quality factor and achieves a wide measurement range and high reliability.

Description

technical field [0001] The invention belongs to the field of micro-electromechanical technology, relates to a micro-inertial sensor, in particular to a resonant pressure sensor based on electrostatic excitation / resistance detection and a preparation method thereof. Background technique [0002] Today's silicon micro pressure sensors based on MEMS technology are widely used in military fields such as fighter jets, including flight data systems, environment and cabin pressure, hydraulic systems in the fuselage, engines and auxiliary power equipment, and various other applications, such as Doors, oxygen masks, flight testing and structural monitoring. The number of pressure sensors used in aircraft, jets, propeller planes and helicopters is also enormous. Therefore, the requirements for the performance index of the sensor (including high precision, sensitivity, etc.) and reliability in complex environments are becoming more and more stringent. Aiming at the modern military's ...

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Problems solved by technology

[0004] For the existing silicon micro-resonant pressure sensor, when the pressure-sensitive diaphragm is deformed under pressure, the height of the resonator will change, but the position of the excitation and detection comb teeth will not change, so the excitation force and detection signal will both decrease, so that not only It increases the difficulty of closed-loop control and also affects the accuracy of the sensor, so there are problems with unstable excitation and detection; and the vibration direction of the resonator of the sensor is perpendicular to the pressure-sensitive diaphragm, so the accuracy is affected by the vibration quality.

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