Hybrid simulation of RF CCPs and their interaction with surface

Radio frequency capacitively coupled plasmas (RF CCPs) are widely used in plasma processes, especially in plasma etching and plasma enhanced chemical vapor deposition (PECVD), on nanometer scales in semiconductor, display and photovoltaic manufacturing. Usually, in RF CCPs for plasma applications, reactive and electronegative mixture gases are adopted in which ions, neutrals and radicals are generated by electron impacted ionization, excitation and dissociation of gas phase molecules, and play a synergistic effect in the surface processing. Understanding plasma physics and chemistry, as well as synergies among species impinging on the surface will be helpful to the optimization of manufacturing processes in plasma reactors. In this simulation work, a fluid model coupled with electron and ion Monte Carlo model is developed to investigate capacitive fluorocarbon or silane containing mixture gas discharges. From the simulation, the energy and angular distributions of the ions, as well as fluxes of positive ions and radicals, are determined and input to the Monte Carlo based profile evolution model to simulate plasma enhanced etching and deposition processes. Ratios of the fluxes of neutrals and ions are concerned as the synergistic effect for different chamber structure and discharge parameters, in order to understand and better control etching and deposition processes. Meanwhile, the increase in the driving frequency and the electrode size would lead to nonuniformity problems that need to be addressed in plasma technologies. However, with the existence of negative ions in electronegative discharges, densities of electrons, positive and negative ions may show different radial distribution profiles, which definitely result in a reduction in the uniformity of the generation rates of the main radicals or precursors. This would lead to a significant decrease in the uniformity of the etching/deposition rate. Data in the surface profile evolution model still need more experimental validation.