High-sensitivity micro-nano giant piezoresistive rain sensor and its preparation method and measurement structure

Abstract

The invention discloses a high-sensitivity micro-nano giant piezoresistive rainfall sensor and a preparation method and a measurement structure thereof. The sensor comprises a sensor array which includes multiple silicon aluminum heterojunction sensing units, power supply electrode pairs, signal detection lead-out electrode pairs and reference lead-out electrode pairs. Each sensing unit includes two silicon aluminum heterojunction pressure sensitive structures, a bottom silicon layer, an insulating silicon dioxide layer and a top silicon layer. The two silicon aluminum heterojunctions which are consistent in structure and property are arranged at the two ends of the sensor in parallel. The side parts of the silicon aluminum heterojunctions are provided with an excitation electrode and a detection electrode. When the sensor is used, mechanical stress of the sensor chip is formed through rainfall pressure and the size of the contact potential barriers of the silicon aluminum heterojunctions is changed so that the giant piezoresistive effect is realized; and the change of the volt-ampere properties of the silicon aluminum heterojunctions acting as a reference part is not caused by stress and the silicon aluminum heterojunctions can act as a differential reference circuit to eliminate the influence of temperature. The sensor is high in measurement sensitivity and accurate and suitable for the occasion of high-precision rainfall measurement.

Description

technical field [0001] The invention relates to the technical field of micro-nano electro-mechanical system (MEMS / NEMS) sensor design, in particular to a high-sensitivity micro-nano giant-pressure rainfall sensor, a preparation method and a measurement structure thereof. Background technique [0002] Meteorology plays an important role in national security, national economy, and the safety of people's lives and properties, and atmospheric pressure is the most basic parameter of meteorological detection. Therefore, the research on air pressure sensors plays an important role in promoting the development of meteorological services. Due to the rapid development of microelectronics and micromachining technology, sensor technology has also been greatly improved. After decades of development, some semiconductor pressure sensors have been successfully used in the field of meteorological measurement, such as air pressure sensors and humidity sensors. However, in terms of rainfall m...

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Problems solved by technology

[0005] However, the current silicon piezoresistive pressure sensor also has the following problems when it is applied to rainfall measurement: (1) The area of ​​a single pressure sensor is limited, and it cannot reliably reflect the change of rainfall

(2) The gauge coefficient of traditional silicon piezoresistors through the doping process is small, about 100, and the piezoresistive pressure sensors of the traditional doping process can no longer meet the sensitivity detection requirements of trace rainfall measurement

(3) The silicon nanowire giant piezoresistive sensor has high sensitivity, but the extremely demanding manufacturing process limits its wide application

(4) The sensor itself cannot distinguish the stress difference between wind force and rainfall, which brings difficulties to the measurement

(5) Meteorological measurements are generally used in places where the temperature changes relatively large, which affects the performance of silicon piezoresistive sensors

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