Chemically reactive discharges are widely used to modify surface properties of materials as well as to perform gas treatment for environmental purpose. A good understanding of plasma processing (etching, thin film deposition or gas treatment) requires basic knowledge about elementary steps of plasma generation.
The course will focus on the fundamental principles of low temperature plasmas, namely on: i) the ignition and the sustaining of the discharge, ii) the charged particle balance, and the ion flux to the surface, iii) RF reactors, iv) the particularities of atmospheric pressure plasmas.

In this lecture, it is described several results of emission and absorption spectroscopy of plasmas for surface processes, including PVD magnetron sputtering and plasma reactors for bacteria inactivation and medical instrument sterilization.
First, it is shown how to determine, by emission spectroscopy, the electron vibrational and rotational temperatures from N₂ spectra.
Then, the method of absorption spectroscopy is described. It is applied to PVD magnetron reactors to determine the absolute densities of neutrals and metal ions, at the example of Ti and Ti⁺ vapour.
In a third part, it is discussed the optical actinometry method to determine the relative densities of active species, such the N, H and O-atoms in N₂-H₂ and N₂-O₂ reactive plasmas. The main kinetic reactions in flowing discharges and post-discharges of these reactive gases are discussed.
It is shown how to determine the absolute densities of N, O and H-atoms by NO titration and by TALIF (Two Photons Laser Induced Fluorescence).
Finally, results are given where the absolute densities of N and O atoms and the UV emission from NO bands are connected to the plasma bacteria inactivation and spore sterilization in plasma post-discharge reactors with N₂ and N₂-O₂ reactive gases at low and at atmospheric pressures.

Magnetron sputtering is a powerful process for deposition of thin films for various applications. Beside metallic coatings obtained by sputtering a metallic target in a neutral argon atmosphere, ceramic coatings can also be synthesised by simultaneously introducing a reactive gas into the reactor.
In this course, we first present the main trends of deposition of pure metal or alloyed coatings obtained by sputtering of pure metal, alloyed or composite targets in the presence of argon. The main features of alloyed coatings deposition is then discussed in relation with the target geometry and the dispersion of the metallic vapour.
The second part is ascribed to the deposition of ceramic compound by reactive sputtering of a metallic target. The main problems related to this technique are presented and the solutions to overcome the drawbacks of arcing and low deposition rate of stoichiometric ceramic films are then discussed. Optical methods allowing the control of the process or that of the growing film are also overviewed.
Finally, we present some examples of applications of (reactive) magnetron sputtering for deposition of coatings dedicated to mechanical applications and we show that magnetron sputtering is also a very pertinent method to produce functional coatings in the fields of optics, ionics and catalysis due to the possible control of the coatings organisation at a nanometric scale.

Plasma Enhanced Chemical Vapour Deposition (PECVD) is a widely used plasma process to deposit various thin films on almost any kind of substrates (silicon, glass, polymers, steel…). Since PECVD allows deposition at low substrate temperatures and leads to films with unique properties which can not been obtained by conventional deposition techniques, it finds applications in many fields such as microelectronic, automobile, aeronautic, food packaging or biomaterial industries. This lecture is devoted to the different steps and mechanisms involved in PECVD : the fragmentation of the gaseous precursor in the plasma, the interactions between neutral active species and positive ions with the surface of the growing film (sticking, etching, recombination reactions…) and the growth of the thin film. The influence of the substrate temperature and the applied bias voltage on the growth kinetics and film microstructure will be presented and discussed. On the basis of examples, it will be shown that PECVD can lead to a wide variety of thin films, from inorganic films (such as silicon oxide or nitride films) up to organic plasma polymer films, from amorphous to polycrystalline films (such as diamond or silicon films) and even to films of oriented carbon nanotubes.

Plasma etching is one of the basic steps used in semiconductor processing for the fabrication of electronic devices. The development of microtechnology has brought implementation of this technique to design central parts of MEMS and MOEMS e.g. for the fabrication of sensors, actuators, photonics and microfluidics devices.
Plasma etching processes are thus asked to produce patterns from the nanometer to the micrometer range and meet in each case various technological requirements, which can prove to be severe.
The lecture will recall the basic aspects of plasma physics and chemistry that characterises plasma etching: etch rate, selectivity, profile control, surface damage… Focus will be set on the complexity of the plasma phase, how the plasma interacts with the surface and how patterning is obtained. Connection will be made with the general characteristics of the various etching equipment used today: conventional systems as planar RF diode, triode or magnetron, high density systems as ECR, TCP or HDP.
The lecture will be illustrated through examples taken from the literature. In particular problems specifically related to the processing of features in Si and SiO² with a small opening and of high aspect ration will be addressed.

After a short review of the definition, characterization of polymer surface and its properties and bio-properties, illustrations of the applications of surface treatments are given. The different surface treatments, i.e. cold plasma and the more classical treatments as chemical, abrasive ones are compared.
The discussion is mainly focused on the plasma treatment and the interactions between the different reactive species of the plasma and the polymer surface. These interactions induce four types of reactions onto the polymer surface: first of all activation, i.e. surface radicals formation, then cross-linking, degradation and functionalization. All these reactions take place, but their rates depend on the nature of polymer surface and plasma. An attention is also pointed out on the ageing properties of the modified surface.
Bioapplications of plasma treated surface or plasma deposited layers will be also described. The 3 types of plasma techniques, i.e. plasma modification, plasma deposition and plasma followed by grafting reaction are used for the fabrication of tools, medical devices and biomaterials. Depending on the application, bioadhesion of cells and biomolecules is either looked for or avoided. Since the mechanisms of bioadhesion depend on the characteristics of the surface: hydrophilic or hydrophobic; modifying the surface by a treatment will alter the bioadhesion. These treatments are developed for the anti-fouling process, the sterilization and the improvement of the formation of biofilms. They have also proved useful for the synthesis of biomimicking devices and sensors.