Highly efficient plasma generation in inductively coupled plasmas using a parallel capacitor

A highly efficient plasma source is developed in inductively coupled plasmas (ICPs) using a parallel capacitor, which is connected to an antenna in parallel. The power absorbed by the ICP is proportional to the equivalent resistance of the ICP. In order to improve the plasma generation, a parallel resonance is used between the parallel capacitor and the equivalent inductance by the plasma and the antenna. In all experiments conducted under an H-mode regime where the inductive heating is dominant, the resistance of a load involving the plasma increases about ten times near the resonance, and the power consumed by the plasma is greatly increased. Consequently, the electron density is greatly increased up to about 350% in the argon plasma and is significantly increased up to about 1000% in the oxygen plasma. For analysis, the transformer model of the ICP and the power balance equation of the global model are introduced, and they show good agreement with the experimental results.