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Diamondlike carbon thin films have been deposited by H2–C2F6 fed rf-glow discharges in a triode reactor. Raman spectroscopy and electron spectroscopy for chemical analysis have been utilized as diagnostic tools to investigate structural properties and chemical composition of deposited films. Transitions in film properties have been observed, from those typical of hydrogenated polymers to those of diamondlike and fluorinated polymers, by changing feed composition, substrate bias, and substrate temperature. In particular, it has been shown that the energy of the ions bombarding the growing films, as well as the fluorine contents in the films is the most critical parameter to obtain materials with diamondlike structure.

Modulated NH3-fed rf glow discharges have been investigated; the emissions of the active species NH* and N2* have been collected during the modulation period (time on+time off). In this study, modulated discharges have been characterized by a constant time on of 7 ms and a tunable time off in the range of 0–1000 ms. It has been found that the power modulation represents an effective tool for selecting excited species: this procedure may be exploited in surface grafting treatments of polymers where high selectivity of chemical groups is requested, e.g., for preferentially grafting −NH2 groups onto polyethylene with respect to all other N-containing functionalities.

Thin transparent polymeric films have been deposited from lowpressure argonltetramethylsilane radio-frequency glow discharges at controlled substrate bias and temperature. The effect of positive ion bombardment and substrate temperature on both film growth rate and chemical composition has been studied. An account of the post-discharge fast oxidation of films exposed to oxygen is also given. A general deposition mechanism% proposed.

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