Synthesis of metal-oxide nanoparticles and utilization of these particles as gate materials for field-effect sensor devices is reported. Improved
selectivity to specific gases is expected by modulating the size of the oxide nanoparticles or impregnating them with catalytic metals. Another
objective is to improve the long-term thermal stability of the sensors, since the metal loaded nanoparticles may prevent thermally induced
restructuring of the gate layer, which is often a problematic issue for the catalytic metal layers. Because of its reasonably high electrical
conductivity, which is especially important for the capacitive gas sensors, ruthenium dioxide has been identified to be one of the potential
candidates as gate material for the field-effect sensor devices. Interestingly, this material has been found to change its resistivity in different
gaseous ambients. When used as a gate material, sensitivity to reducing gases has been observed for the RuO2/SiO2/4H-SiC capacitors.
Changes in the resistivity of the films due to various gas exposures have also been recorded. Morphological studies of nanoparticles (SiO2
and Al2O3), loaded or impregnated with catalytic metals (e.g. Pt), have been performed.
Elsevier , 2005. Vol. 107, no 2, p. 831-838