This paper reports on the preparation, electrical and surface characterization of Cu doped tin dioxide thin-films for highly selective integrated gas sensor devices. The 3000 angstroms thin-film of 0.16 wt.% copper doped tin dioxide was deposited by reactive R.F. sputtering at room temperature and followed by 10 angstroms Pt on top of Cu doped tin dioxide thin-film (SnO2-Cu/Pt). In another batch, the 100 angstroms SiO2thin-film was deposited on top of the SnO2-Cu/Pt thin-film structure (SnO2-Cu/Pt/SiO2). The electrical response of these thin-films was investigated for CO and H2gases at different temperatures and gas concentrations. The device with the SnO2-Cu/Pt thin-film, showed excellent electrical response towards CO gas and device with SnO2-Cu/Pt/SiO2thin-film showed response towards hydrogen only. The SiO2thin-film prevents the diffusion of CO gas and only hydrogen gas diffuse through silicon dioxide layer. Using thin-films structure SnO2-Cu/Pt and SnO2-Cu/Pt/SiO2, a highly selective sensor device for CO and H2gas was fabricated. The surface characterization of these thin-films was performed using scanning electron microscopy (SEM) and X-ray photoemission spectroscopy (XPS) techniques. The SEM picture showed that surface structure of the SnO2thin-film improved by copper doping.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry