High efficient plasma generation in an inductively coupled plasma using a passive resonant antenna

We developed a high efficiency plasma source in an inductively coupled discharge using a passive resonant antenna, which has the advantage that it could be retro-fitted to existing reactors with minimal change to the reactor. At the resonance, the source has a larger total equivalent resistance that is 3-18 times larger than that at the non-resonance. As the resistance increases at the fixed RF power, the RF current decreases accordingly, which indicates that the power loss in the powered antenna including the impedance matching circuits is significantly reduced. The experimental result shows that the power transfer efficiency is improved by about 30%-70% and the plasma density at the resonance increases 2-8 times higher than that at the non-resonance. For analysis, three-winding transformer model is developed. The experimental results are consistent with the model.