THREE-DIMENSIONAL FLUID SIMULATION OF LARGE-AREA RECTANGULAR INDUCTIVELY COUPLED PLASMA SOURCES

In this paper, a three-dimensional fluid model has been developed to investigate the properties of large-area rectangular inductively coupled plasma (ICP) sources for flat panel display processes and photovoltaic processes. The model self-consistently solves the fluid equations for charged particles as well as neutral particles and the wave equations for the inductive electric field. Using this model, the effects of gas pressure, discharge power, and coil structure on the three-dimensional spatial distribution and uniformity of various plasma parameters are investigated. The results indicate that when the gas pressure is low (4 mTorr), the electron density is uniformly distributed and is the highest at the center of the chamber. The maxima of the inductive deposition power density, excited state argon atom density, and electron temperature are below the coil. With the increase of the power, i.e., from 1000 W to 4000 W, the electron density becomes higher and the spatial uniformity is nearly unchanged. However, as the gas pressure increases, the plasma uniformity becomes worse, and the maximum of the electron density appears below the coil. This is due to the fact that at higher gas pressure, the collisions of charged particles with the background gas are enhanced, making the density distribution more localized. Besides, the effect of the coil structure on the plasma uniformity is investigated. At 20 mTorr, the plasma generated by the 3 \times 3 array coil is more uniform than that generated by the rectangular single-planar coil. The results obtained in this work could help us to gain deep insight into the large area rectangular ICPs, which is of significant importance to improve the flat panel display and photovoltaic processes.