| AVS 64th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Tuesday Sessions |
| Session PS-TuP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | Xiaopu Li, Applied Materials, Inc. |
| Authors: | X. Li, Applied Materials, Inc. K. Bera, Applied Materials, Inc. J.A. Kenney, Applied Materials, Inc. S. Rauf, Applied Materials, Inc. K.S. Collins, Applied Materials, Inc. |
| Correspondent: | Click to Email |
Very high frequency (VHF) capacitively coupled plasmas (CCP) are widely used for materials processing in the semiconductor industry. The spatial distribution of plasma in CCP discharges can be affected by electromagnetic effects. In this study, a VHF linear plasma source is considered, which consists of parallel metal bars enclosed within ceramic insulator tubes. The linear source is immersed inside the discharge volume, which is enclosed by a grounded metal box except for the input and output ports. A full three dimensional electromagnetic plasma model is used to understand the interactions between the external radio-frequency source and the plasma. The fluid plasma model computes species densities and fluxes, as well as the plasma current density. Drift-diffusion approximation is used for species fluxes in the continuity equations for all charged species. Neutral species concentrations are determined by solving the continuity equations with diffusion coefficients computed using the Lennard-Jones potentials. The electromagnetic phenomena are fully described by the Maxwell equations with the plasma current density updated from the fluid model. The RF source in the model excites a transverse electromagnetic (TEM) wave through the input ports. The CPML absorbing boundary condition is applied at the termination port to avoid electromagnetic wave reflections back into the plasma. The finite difference time domain (FDTD) technique is used to discretize the Maxwell equations, which are solved explicitly in time. Ar discharge is studied based on the reaction mechanism similar to the previous study [1]. The plasma density profile is found to be dependent on excitation frequency, pressure and power. The spatial distribution of plasma with in-phase and out-of-phase excitation from the ports is investigated as well.
1. S. Rauf and M. J. Kushner, J. Appl. Phys. 82, 2805 (1997)