Design of Gas-Sensing Films for MEMS Sensors

Abstract

Various types of SnO₂-based thin films were fabricated as a gas-sensing film of MEMS sensors by utilizing radio-frequency magnetron sputtering. Pt-sputtering on the SnO₂ film improved responses to both 1000 ppm H₂ and 50 ppm ethanol, while Pd-sputtering on the film showed the reverse tendency, i.e. ineffectiveness in improving the responses. Furthermore, hetero-stacking of a SnO₂ film on the Pt-added SnO₂ film was very effective in enhancing the H₂ response.