Fluorination by Cold rf Plasmas

Radio frequency plasma fluorination is a low-temperature process where fluorinated gases are excited by an rf source and dissociated into chemically active atoms, radicals and molecules. Several fluorinated gases were used CF4, CsFg and c-C4Fg, which were excited by a rf source at 13.56 MHz. A primary vacumn was obtained by a 40m. h pump equipped with a Uquid nitrogen condenser, which trapped the residual gases. The reactor comprised two cylindrical barrel-type aluminium electrodes which were coated with alumina and which were located within a distance of 2 cm from each other and several gas inlets allowing the use of gas mixtures. The inner electrode was connected to the rf 

The treated substrates were composed of a porous, 5 m-thick, alumina layer elaborated onto an alumina plate of 0.3 mm. These plates, provided by AGFA-Gevaert, were protected with a gum layer. Before using the plate, this layer was removed with rinseage with distilled water and dried by compressed air. In order to characterize the treated plates, two main techniques were used contact angles measurements and X-ray photoelectron spectroscopy (XPS or ESCA). 

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