Fluorocarbon films are deposited by rf sputtering of poly(tetrafluoroethylene) targets under conditions of various power and pressure levels in pure argon in order to examine the effect of discharge conditions on the deposition rate and molecular structure of the deposited films. The molecular structures of the films are investigated by means of X-ray photoelectron spectroscopy. The films deposited under conditions favoring high deposition rate, such as higher power at a constant pressure or lower pressure at a constant power, contain higher concentrations of cross-links. Heating the deposited films results in an increase in the component of the C1s spectrum assigned to the cross-linked structure.

Thick film gas sensor of tin oxide based materials has been developed by screen printing method, and its sensing characteristics have been examined for some gases. To perform the method, tin oxide fine power with the size about 0.5 μm in diameter was prepared through the fine crystallization in liquid phase, and was mixed with glass frits as a binder and palladium or platinum as a catalyst. This mixed material is used as the paste. With the screen printing method using the paste, the mass production and the sufficient mechanical strength of the sensor can be achieved. The gas sensor of tin oxide incorporated with palladium black as the catalyst shows an excellent selective detection for ethanol and hydrogen gases at the specimen temperature of 250 °C. And the platinum black-doped tin oxide sensor has also a high sensitivity to both gases at the temperature over 350 °C.

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