Sensing characteristics of SnO2 thin film gas sensor

Abstract

The Pd‐doped SnO₂ thin film detector for gaseous components has been developed, whose detection is based on the fact that the adsorption and desorption of gases cause the remarkable change in electrical resistivity of the semiconductor. This property of SnO₂ film is applicable to the preferential detector for gaseous components, especially ethanol gas. SnO₂ thin film was prepared on the polished ferrite substrate which SiO was precoated. Both the preparation and the precoating were done by vacuum deposition. Subsequently the oxidation for SnO₂ film in air was done at 500–550 °C for 30–60 min. The rise rate and fall rate of temperature were 2.5 and 1.7 °C/min, respectively. The thickness of SnO₂ film was about 0.3–0.35 μm.