A new zinc oxide nanowire (NWgas sensor based on the commercially available 0.35mm complementary metal-oxide-semiconductor (CMOSprocess is developed. The smart gas sensor consists of a gas-sensing resistor and an interface circuit for resistance measurement. The single ZnO NW synthesized by the vapor-liquid-solid (VLSprocess is utilized as the gas-sensing resistor. The interface circuit for the resistance measurement of the single ZnO NW is composed of a ring oscillator circuit, in which the oscillation period is optimized with regards to the ZnO NW resistance and external capacitance to accurately detect the resistance of the ZnO NW after exposure to the gas. Because the low-frequency noise contains information about the charge fluctuations which are important for determining the gas-sensing reliability, the low-frequency noise of the single ZnO NW at various gate voltages, source-drain voltages and resistances is systematically characterized and compared with those of CMOS field-effect transistors (FETsand network carbon nanotubes (CNTsresistor.
ASJC Scopus subject areas
- General Engineering
- General Physics and Astronomy