Remote nitrogen microwave plasma chemical vapor deposition from a tetramethyldisilazane precursor. 1. Growth mechanism, structure, and surface morphology of silicon carbonitride films

Silicon carbonitride (Si:C:N) films were produced by remote microwave nitrogen plasma chemical vapor deposition (RP-CVD) using a 1,1,3,3-tetramethyldisilazane precursor. The reactivity the precursor with atomic nitrogen was characterized using hexamethyldisilazane as a model compound. The effect of the substrate temperature (TS) on the kinetics of the RP-CVD process, chemical composition, structure, and surface morphology of resulting film has been investigated. The temperature dependencies of the mass- and thickness-based film growth rate imply that for low substrate temperature range (TS = 30–200 °C) film growth is limited by desorption of film-forming precursors, whereas in high substrate temperature range (TS = 200–400 °C) film growth is independent of the temperature and the rate of RP-CVD is mass-transport limited. The increase of the substrate temperature from 30 to 400 °C causes the elimination of organic moieties from the film and the formation of Si–N and Si–C network structure. The hypothetical chemical reactions contributing to film formation are discussed. The films were found to be morphologically homogeneous materials exhibiting very small surface roughness for higher substrate temperatures (TS = 200–400 °C).