Publications: Articles

Equipe: Département CP2S : Expériences et Simulations des Plasmas Réactifs - Interaction plasma-surface et Traitement des Surfaces ESPRITS

Equipe: Département CP2S : Expériences et Simulations des Plasmas Réactifs - Interaction plasma-surface et Traitement des Surfaces ESPRITS

Resume: The deposition of multiple carbon atoms on a crystalline silicon (Si) surface is modelled at 5 eV energy by using molecular dynamics simulations combined with a third generation force field that includes bond breaking and formation. Force field parameters are taken from a previous work. These simulations allow for atomic scale insights into the deposition mechanisms and an easier comparison with experimental observations. The results, including distributions of implantation depth, carbon concentrations, sticking coefficients, radial distribution function, and angular distributions are compared for different incidence angles. Due to the deposition of carbon atoms inside the silicon structure, silicon carbide starts to form. The crystalline structure has been investigated for different conditions to get a better understanding of the damaging and growth mechanisms. It is found that a lot of deformation is accumulated in the area of deposition near to the surface but underneath the surface the silicon has still a more crystalline structure. The variation of the silicon (carbide) structu re slightly depends on the angle of incidence. For the conditions used for these simulations, the sticking probability is always high and varies between 95% and 100%, which can be attributed to the high affinity of carbon for silicon.

Equipe: Département CP2S : Expériences et Simulations des Plasmas Réactifs - Interaction plasma-surface et Traitement des Surfaces ESPRITS

Equipe: Département CP2S : Expériences et Simulations des Plasmas Réactifs - Interaction plasma-surface et Traitement des Surfaces ESPRITS

Resume: The electron temperature and electron density are measured in a microwave (MW) plasma-assisted chemical vapour diamond deposition reactor for different experimental conditions by varying the substrate temperature, methane content and MW power density. Optical emission spectroscopy (OES) and MW interferometry are used to probe the discharge generated in a stainless steel resonant cavity excited at a frequency of 2.45 GHz. Changing the substrate temperature from 630 to 900 ?C does not show any significant influence on the electron temperature or on the electron density. Increasing the methane content from 0 to 10% does not lead to any modification of the electron temperature or density. However between 10% and 20% CH, a decrease of the electron density is observed which may be attributed to soot particle formation. The electron density increases in the range of (1.2-10) x 1011 cm-3 from moderate power density conditions (50 hPa/1000 W) to high power density conditions (250 hPa/3500 W). OES measurements show that the electron temperature exhibits a flat axial profile in the plasma bulk and ranges from 14 000K at (25 hPa/600 W) to 10 500K at (400 hPa/3000 W).

Equipe: Département CP2S : Expériences et Simulations des Plasmas Réactifs - Interaction plasma-surface et Traitement des Surfaces ESPRITS