Abstract
In this study, we use fluid model to simulate capacity coupled plasma enhance chemical vapor deposition using in diamond deposition with CFD-ACE+. In order to simplify the simulation, we use sticking coefficient to define the species flux to the boundary and do not consider the surface reaction when growing film. Also, we assume that when ions strike to the wall, they will absorb electrons from the wall and reflect to the chamber as neutral particles. First, we compare our result with data in the literature for reliability confirmation. The reaction mechanism is determined by modifying the reaction mechanisms available in the literature. With the distributions of electron density, electron temperature, species number density in the reactor are analyzed for pure CH4 under a fixed temperature of 300 K and pressure of 300 mtorr, the most influential reactions to the generation and consumption of CH3, CH2 and H, the most influential species in diamond growth, are identified. Subsequently, the effects of different inlet arrangements and inlet CH4/H2 mixtures. When the inlet is located on the outer rim of the upper surface, slightly higher CH3 concentration is obtained above the substrate. This is because the transport process is mainly by diffusion, so that there is longer species residence time above the substrate when the gas flow enters through the outer rim. When the mixture is 20 sccm CH4 with 80 sccm H2, there can be uniform CH3 distribution with high H density above substrate so that uniform and good-quality diamond film deposition may be expected. Furthermore, analyses for different chamber temperatures (300 K, 400 K, and 500 K) reflected different chemical compositions due to the temperature effect.