Influence of oxide film surface morphology and thickness on the properties of gas sensitive nanostructure sensor

743-749In this study, the gas sensitive metal-oxide semiconductor (MOS) nanostructure sensors based on Ni thin film have been fabricated. The influences of SiO2 film surface morphology and thickness on the response (R%) and electrical properties of the sensors have been investigated at 150 °C. The surface morphology of the SiO2 film has been characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The C-V curves of the MOS nanostructure sensors in pure nitrogen and 2 % hydrogen have been reported as well. For the SiO2 film thicknesses of 14, 65 and 74 nm the measured flat-band voltages (VFB) are 0.7, 1.5 and 2 V, respectively. The responses of different sensors in 2% hydrogen for SiO2 film thicknesses of 14 and 74 nm are 84% and 32%, respectively. The MOS nanostructure sensors exhibited good response to the hydrogen gas, with excellent sensitivity. The MOS nanostructure sensor based on Ni thin film and SiO2 film thickness of 14 nm shows high response and sensitivity