Plasma Density Distribution in Asymmetric Geometry Capacitive Coupled Plasma Discharge System

In this work, we used the single Langmuir probe to measure the plasma density distribution in an geometrically asymmetric capacitive coupled plasma discharge system. Because of the frame structure of powered electrode, the plasma density was not homogeneous in the discharge volume. It was higher under the frame, but lower in the centre. Finite element simulation results showed a good agreement with the experiment results. To increase the electron density in the central volume and improve the homogeneity of the plasma, we added an auxiliary electrode, powered by DC voltage, in the simulation geometry. The simulation results showed that the auxiliary electrode could alter the potential distribution and improve the density homogeneity effectively.

Authors:

• Yinchang Du
• Yangfang Li

Keywords:

• Capacitive coupled discharge
• asymmetric discharge
• homogeneous plasma.

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