Influence of Sputtering Power, Annealing on the Structural Properties of ITO Films, for Application in Ethanol Gas Sensor

Indium tin oxide films were deposited at different sputtering power on to the glass substrate maintained at a temperature of 648 K by fry magnetron sputtering technique. Influence of fry power and annealing, on the structure and growth of ITO film is investigated. A gas sensing unit is designed and the gas sensing properties of the film towards ethanol gas is studied. The X-ray diffraction (XRD) analysis proves the films have preferred crystal growth towards (2 2 2) direction and average size of grains are 57 nm. The annealing improved the crystallinitiy and texture of the film. The ITO thin film sensor showed a linear response to ethanol gas in the concentration range of 200 to 1400 ppm. Post-deposition annealing of the film at 700 K enhanced the response of the sensor.