Transport Phenomena in an Atmospheric‐Pressure Townsend Discharge Fed by N₂/N₂O/HMDSO Mixtures

Abstract

This paper focuses on the understanding of the main mechanisms that participate in the growth process of an SiO2‐like film in an atmospheric pressure Townsend discharge in N2 with small ad‐mixtures of HMDSO and N2O. The approach consists of analyzing the influence of operating parameters on the growth rate profile through a fluid dynamics model. The suggested chemical mechanism is constituted by one volume reaction and one surface reaction. This simple model enables us to assume which phenomena control the film growth process among the following mechanisms: HMDSO dissociation by N2(A3Σ) in Si‐containing radicals, radicals transport to the surface, and surface activation process by plasma.magnified image

Anti-Fog Layer Deposition onto Polymer Materials: A Multi-Step Approach

“…This stoichiometry (O/Si * 2.2) was previously attributed to the presence of silanol groups (Si-OH) which have already been evidenced by FTIR analyses [23,35,36]. Moreover, as expected, the addition of N 2 O during the plasma process led to an inorganic surface with no incorporation of N. Similar observations are reported in other studies [23,[37][38][39].…”

Effect of C2H4/N2 Ratio in an Atmospheric Pressure Dielectric Barrier Discharge on the Plasma Deposition of Hydrogenated Amorphous Carbon-Nitride Films (a-C:N:H)

“…In addition, volatile species desorption is quite low under atmospheric pressure, thus adsorbed species on the surface efficiently contribute to the coating. Furthermore, according to a numerical modeling of the reactive transport in an atmospheric pressure DBD with a longitudinal injection, and under similar discharge conditions [60], diffusion of the reactive species is the limiting factor for the deposition process, whereas gas convection is the dominant force for moving the molecule, which means that radicals leading to the growth must be created in a boundary layer close to the surface. The thickness of this boundary layer is defined by (a) the diffusion coefficient of the radicals and the gas flow which determines their trajectory and (b) the volume reactivity of the radicals which determines their lifespan.…”

Organosilicon Polymers Deposition by PECVD and RPECVD on Micropatterned Substrates

“…[16] The simulation tools were developed for etching purposes through 2D-and 3D-models. [5,17] To the best of our knowledge, however, only a small amount of literature regarding the modeling of the growth of organosilicon polymer films [18][19][20] can be found, due to the lack of experimental data on the chemistry of such complex media. Nevertheless, a number of works deal with trench filling and conformality in the case of plasma polymer deposits.…”