CVD Deposited Titania Thin Films for Gas Sensors with Improved Operating Characteristics

This paper describes the results of experimental evaluation of titanium dioxide thin films formed by CVD as active layers in semiconductor, resistive sensors for detection of ethanol vapors. TiO 2 layers with a thickness of 90 nm are formed by CVD in the TTIP‐O 2 ‐O 3 ‐Ar reaction system. Sensors manufactured with titania films formed under all the deposition conditions studied exhibit good electrical response to the ethanol vapors, with quick response‐recovery characteristics in the temperature range 170–300 °C. Sensor performance is determined by the relative amount of anatase phase and grain size in the films. The response value ( R air / R ethanol ) of the sample with the highest degree of crystallinity reached 37 at an operating temperature of 200 °C.