An Integrated Impedance Load Surface Acoustic Wave Gas Sensor

Abstract

The invention discloses an integrated impedance-loaded sound surface wave gas sensor based on a Si (silicon) substrate. The integrated impedance-loaded sound surface wave gas sensor comprises a substrate, a piezoelectric layer, an input / output interdigital transducer, a reflective interdigital transducer, a sensitive interdigital electrode and a gas-sensitive thin film. The integrated impedance-loaded sound surface wave gas sensor has the advantages that by growing one thin SiO2 (silicon dioxide) insulation layer and one piezoelectric layer on the Si substrate, the good temperature characteristic is realized; the material of the Si substrate has the characteristics of low cost, large size and conductivity, and can be combined with the integrated circuit industry; the arrangement structure of the interdigital electrode is optimized, the sound wave reflection caused by the external sensor is reduced, and the parasitic effect caused by connecting wires is reduced; the interdigital transducer and the sensitive interdigital electrode are manufactured by one step, so that the simplicity in the manufacturing process is guaranteed, and the large-scale production is easily realized; the wireless passive measuring of the sensor is realized, the sensing part which is easily influenced by outside is separated from a signal sending part, and the application range of the sensor is widened.

Description

technical field [0001] The invention belongs to the technical field of surface acoustic waves, and more specifically relates to an integrated wireless passive impedance load surface acoustic wave (SAW) gas sensor based on semiconductor material Si. Background technique [0002] Since external factors (such as temperature, humidity, pressure, magnetic field, electric field, etc.) will change the transmission characteristics of SAW, and SAW devices work in the radio frequency band and have strong anti-electromagnetic interference capabilities, the application of SAW sensors is becoming more and more extensive. The existing SAW device is composed of a piezoelectric material substrate and an interdigital transducer (IDT) with different functions deposited on the substrate, while the existing SAW gas sensor is covered with a layer of gas sensor on the basis of this structure. The thin film reacts with the gas to be detected to change the transmission characteristics of the SAW in...

AI Technical Summary

Problems solved by technology

[0008] In view of the above defects or improvement needs of the prior art, the present invention provides an integrated wireless passive impedance load SAW gas sensor, the purpose of which is to integrate the SAW signal transmission chip and the external sensing structure on the Si substrate structure, This solves the technical problems of complex process, high cost, low production efficiency, poor high-frequency and high-temperature characteristics and difficult integration in the existing technology

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