Gas phase and surface kinetics of diamond-like carbon films growth in pecvd reactors

摘要

The surface and gas-phase kinetic of deposition of diamon-like carbon films (DLC) obtained in plasm reactors using methoane a s precursor was here investigated. Kinetic constants of electronic reactions were evaluated using experimental ionization and neutral dissociation cross sections and the Druyvestein elecgtron distribution function. Kinetic constants for ionic and neutral reactons were found in the literature. Surface reactions were divided into processes involving the impingment of gas-phase readicals or ions from the plasma and desorption or recombination reactions of adsorbed surface species. The kinetic constants of the former processes were evaluated. from the ambipolar theory or from the kinetic theory of gases while the other kintetic constants were determined from analogy with hydrocarbon chemistry. The exeption is the desorption of adsorbed methyl radicals, whose kinetic constant was fitted over experimental data. Thepredictivity of the model was tested through the simulation of three reactors described in the literature widely differing for operating conditions.