Miniaturization of thermoelectric hydrogen sensor prepared on glass substrate with low-temperature crystallized SiGe film

A miniaturized thermoelectric hydrogen sensor operating with the complex mechanisms of thermoelectric effect of SiGe film and catalytic exothermic reaction of hydrogen oxidation of Pt film was prepared. The active films of SiGe and Pt were deposited by rf-sputtering method. Transparent glass substrate was used for the preparation of the miniaturized hydrogen sensor because of its convenience for aligning different patterns with a simple process. As the as-deposited SiGe film was amorphous, the strategy of Ni-induced crystallization that was commonly used for the preparation of poly-Si film was employed in this work to get the SiGe film crystallized at the glass-endurable temperature. Based on the investigation of Pt catalyst activity for the influence of the film thickness and the area size, miniaturized thermoelectric hydrogen sensor with favorable sensing properties was achieved. Besides this, the influence of the SiGe film crystallinity on the sensitivity and the detectable concentration and the effect of the sensor pattern on the general performance were also examined. (C) 2004 Elsevier B.V. All rights reserved.