Abstract: A device for coupling microwave energy with at least one exciter, and for distributing it therealong for the purpose of producing a plasma, includes a first enclosure whose inside is bathed in microwave energy, a second enclosure containing a gaseous medium to be ionized, and a first series of at least one communication passage between the two enclosures. An exciter is mounted to pass through each communication passage at a distance from the inside surfaces and to extend into the first and second enclosures in order to couple with a portion of the microwave energy and convey the coupled microwave energy locally into association with the gaseous medium. The exciter constitutes, together with the passage and portions of the sidewalls of the enclosures facing the exciter, a coaxial-type structure.

Abstract: This invention relates to a process for surface treatment of a substrate carried by an electrode and immersed in a sealed engraving or deposition chamber equipped with plasma generating means, of the type involving the application to the electrodes, of a variable voltage, produced by a generator that is independent of the plasma generating means, wherein said process comprises the steps of:maintaining within said chamber a continuous plasma that is free of electromagnetic fields;supplying said electrode via a low impedance capacitor using a signal comprised of rectangular voltage pulses having:a variable pulse repetition rate to control the energy distribution function of the positive ionic charges bombarding the substrate,a variable mark-to-space ratio for each pulse to control the time distribution of the negative electron charges and the positive ionic charges bombarding the substrate, anda variable pulse amplitude to control the energy of the positive ionic charges bombarding the substrate.