Modelling the pulsed glow discharge of a nitriding reactor

Through a detailed study, involving a close coupling between numerical modelling and experimental investigations, a better understanding of the underlying physical mechanisms in the low-frequency DC pulsed regime of a nitriding plasma reactor has been obtained. The modelling, based on a one-dimensional electric model with two populations of electrons (beam and bulk), leads to an accurate description of the different regions of the discharge, including the negative glow. Current-voltage characteristics of the discharge as well as the evolution of line emission intensities measured by space-and time-resolved optical emission spectroscopy, have been obtained for various operation regimes. In analysing the experimental results obtained, together with relevant simulations, clear evidence has been obtained that a heating process of the neutral gas occurs and plays an important role in usual operation regimes. An actual self-consistent modelling including this effect is under way. (C) 1997 Elsevier Science S.A.