Integrated Thin Film Gas Sensors

In the last few years, much attention has been attracted to micro gas sensors in the field of gas sensing technology. The integrated thin-film gas sensor was a new generation of gas sensor with the advantages of low power consumption and ease of integration, in which the heater, temperature detector, electrodes and sensitive thin film were integrated with the combination of microelectronic, micromachining and thin film technology. In the thesis, an integrated thin-film NO₂ gas sensor was realized by technologies of microelectro-mechanical systems (MEMS). The work principle of sensor was presented theoretically. The structure and technological process were designed, simulated and optimized. The resistance-temperature relations of polysilicon were measured. The sensitive film was CuPc and its structure and sensitive mechanism were given. The CuPc was synthesized and its thin film was prepared by vacuum evaporation. The characteristic results of sensitivity, temperature, response time and recovery time of thin film were given.