Surface acoustic wave gas sensor and manufacturing method thereof

Abstract

The embodiment discloses a surface acoustic wave gas sensor and a manufacturing method thereof. The surface acoustic wave gas sensor is used for detecting concentration of NO2, and the method comprises: providing a substrate which comprises a main body layer, an input interdigital energy transducer and an output interdigital energy transducer, wherein the input interdigital energy transducer and the output interdigital energy transducer are arranged on the surface of the main body layer; forming a photosensitive layer on the substrate surface, and forming sensitive membrane region pattern on the photosensitive layer surface; forming a composite membrane with In2O3Ag on the substrate surface by using the photosensitive layer with the sensitive membrane region pattern as a mask layer; and then removing the photosensitive layer material to obtain a sensitive membrane which is arranged on the surface of the main body layer between the input interdigital energy transducer and the output interdigital energy transducer. The sensor in the embodiment of the invention has high sensitivity and rapid response speed under normal temperature, and can precisely measure the concentration of NO2.

Description

technical field [0001] The invention relates to the technical field of surface acoustic wave gas sensor manufacturing, and more specifically relates to a surface acoustic wave gas sensor and a manufacturing method thereof. Background technique [0002] With the rapid development of socio-economic technology and industry, the volume fraction of air pollutants monitored in real time on site is often as low as 10 -6 even 10 -9 level, which requires the sensor to monitor the pollution gas to have sufficient sensitivity and selectivity. Compared with other types of sensors, surface acoustic wave (SAW) gas sensors have many excellent characteristics, such as small size, light weight, high precision, high resolution, strong anti-interference ability, high sensitivity, and good linearity in the effective detection range. features. [0003] The basic structure of SAW gas sensor is as follows: figure 1 As shown, on the surface of the piezoelectric material as the substrate, one en...

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Problems solved by technology

[0006] to NO 2 Gas monitoring as an example, the sensitive film in the prior art has TiO 2 Film, V 2 o 5 Composite film doped with Ag, SnO 2 thin film, ZnO thin film, MWCNTs thin film and indium tin oxide thin film, etc., but most of the sensors prepared with these sensitive films have good sensitivity and selectivity only when they are detected at high temperature, and the high temperature environment not only affects the sensor measurement Therefore, it is urgent to manufacture a sensor with high sensitivity at room temperature, fast response, and accurate measurement of the concentration of the gas to be measured.

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