Thin (NiO)1-x(Al2O3)x, Al doped and Al coated NiO layers for gas detection with HSGFET

Work function changes of (NiO)(1-x)(Al2O3)(x), Al doped and Al coated NiO layers upon NO2, CO2, SO2, Cl-2, CO, NH3 and H-2 at 30 degrees C and 130 degrees C were measured by means of a Kelvin probe. Compared to the 'pure' oxides NiO and Al2O3, a significant impact of the stoichiometry.x, the Al dopant concentration and the Al surface modification not only on the sensitivity, but also on the selectivity and the response behaviour of the samples was found. The material screening was carried out with respect to the incorporation of the most sensitive and selective layers into hybrid suspended gate FET (HSGFET) devices. The sensor measurements were found to be in good agreement with those carried out by the Kelvin probe. (C) 1998 Elsevier Science S.A. All rights reserved.