Stéphane Lucas

Plasma treatment of cold-rolled steel : actual state, problems to overcome and future

Abstract The corrosion protection of steel substrates is an important industrial process for many industries such as the automotive industry, the packaging industry etc. The most common methods of corrosion protection of steel surfaces are actually hot-dipping and electrodeposition. However, these methods suffer from several drawbacks: weak variety of coatings, multilayer deposition nearly impossible, important disposal and recycling costs. It is known that plasma deposition (including sputtering) of thin films can give a very dense structure with uniform deposition, low number of pinholes and adequate long-term corrosion performances. Most of the work in the plasma deposition has been restricted to small objects. Plasma processing for larger objects has been used preliminarily for plastic and glass substrates, but rarely on metallic substrates. In this paper, we shall discuss some of the literature and personal work related not only to surface cleaning and corrosion protection of steel but also to interface engineering for the improvement of paint adhesion. Type of coating, properties achieved will be discussed bearing in mind the industrial application. In addition, some technological aspects related to a continuous in-vacuum coating line will also be addressed. Finally, a few guidelines will be drawn for the implementation of vacuum technology in industry.

Study of the formation of a carbon layer on a sputtering target during magnetron-enhanced reactive sputtering

Abstract The goal of this work is to estimate and to discuss the optimum conditions for the realization of hydrogenated carbon deposits obtained by magnetron-enhanced reactive sputtering in a C 2 H 2 -Ar gas mixture with a carbon autofeeding target system. Hydrogenated carbon layers can be obtained by reactive sputtering of a copper target poisoned by carbon compounds during the deposition process. It is shown that the target poisoning rate, composition and structure depend on the gas composition (C 2 H 2 -Ar) and on the sputtering conditions (target current). The target poisoning rate is compared with the deposition rate of the hydrogenated carbon deposit on a silicon substrate and related to an analysis of the gas discharge by emission spectroscopy for different experimental conditions. The structure of the carbon-poisoning layer is also compared with the structure of the carbon layer deposited on a substrate. The hydrogen-to-carbon ratio is determined on both the target and the substrate by elastic recoil detection analysis.