Vera Hrachova

APPLICATION OF CHROMATIC MONITORING AS A PLASMA DIAGNOSTIC TECHNIQUE

This paper describes the application of chromatic monitoring of both laboratory and industrial plasmas. The light emitted from the nitrogen plasma generated in the different plasma sources was measured with an imaging spectrograph. The emission spectra were reduced to data points representing the chromatic coordinates of these spectra. The data compression makes this method attractive for monitoring plasma parameter changes. The aim of this work was to test the possibility of application of chromatic monitoring for plasma processing.

Reduction of reaction mechanisms in plasma chemistry

Summary form only given. When studying the chemically active plasmas by the methods of computational physics, the macroscopic kinetic approach proved to be very convenient. The models are based on the systems of chemical reactions between active species in the discharge, from which the continuity equations for concentrations of individual species are derived. However, in many cases the kinetic scheme of the model is very complicated and the set of input chemical reactions must be reduced first in order to be able to solve the model. Various techniques for model simplification can be found in the literature - e.g. approaches based on the sensitivities of individual reactions, on the corresponding reaction rates, on time-scale separation, etc. The technique used in our contribution is based on the monitoring of the speed of every reaction during the kinetic calculations, resulting in weight factors of reactions describing the relative importance of individual reactions in kinetic scheme1. The main goal is to preserve only the reactions influencing profoundly the resulting concentrations of main products or products important for given application.

Properties of T and H forms of DC glow oxygen discharge sustained at medium pressures up to 1000 Pa

Summary form only given. The DC glow discharge in oxygen and its mixtures can be utilized in many applications (e.g. plasma etching, sterilization, thin layer deposition or treatment). Oxygen plasma is therefore subject of both numerical and experimental studies. One of the important discharge parameters is the kinetic temperature of the neutral particles which often governs rate constants of various processes such as dissociation or diffusion. Considering the case of oxygen, the kinetic temperature can be simply obtained by its comparison with rotational temperature T rot determined from emission spectra of the oxygen molecule1.

Plasma formation of thin alumina films

An oxidation of aluminum films in oxygen plasma of dc glow discharge is studied by computer experiment. The necessary data is derived from direct measurements. The complete model consists of three parts -- the modeled source of the oxygen plasma, the model of the transport of charged particles through the sheath between undisturbed plasma and substrate and, finally, the description of physical processes occurring during oxide formation on the solid surface. The description of volume interactions which takes part in the undisturbed plasma was based on a macroscopic kinetic approach with 12 kinds of charged or excited particles. As a result of the first part of the model the steady-state concentrations of all kinds of particles were derived. These results are used as input data for the second part of the model, which is the main task of the present paper. The physical processes which take part in the interaction of plasma- aluminum substrate were analyzed by the iterative hybrid method -- a combination of molecular dynamics and Monte Carlo approaches. This method was employed to study the transport of charge in the self-consistent electric field under the influence of interactions with neutral species in the sheath. Both the plasma oxidation and plasma anodization were modeled and the effects of varying bulk plasma and sheath parameters on the ion and electron distributions at aluminum surface were examined. These particles can be used in the third part of the complete model to analyze the growth of alumina film.