Nano-Wire Grown Micro Thin Film Sensors and Their Gas Sensing Properties

SnO2 nanowires were grown on the surface of SnO2 thin film by heat treatment of metal Sn film under Ar gas flow at atmospheric pressure. Generally, the nanowires of metal oxide semiconductors are known to be grown at low pressure (below 0.02 Torr) and at high temperature (over 1,000 ℃). The deposited Sn metal films were annealed at temperatures of 700 ~ 900 ℃ for 3 hours. The sensitivity of the thin film device on which nanowires were grown to CO gas (1,000 ppm) was 60 % at the operating temperature of 250 ℃. And it was found that the sensitivity to CO and C4H10 gases for the device annealed under Ar gas flow was much higher than those for device annealed under O2 gas flow