플라즈마 공정 장비에서의 변압기를 이용한 전력변환 효율 개선 연구

Abstract

A study on the efficient power transfer to plasmas using a transformer was developed to reduce the power loss at the feeding line in a capacitively coupled plasma (CCP). At 20 mTorr ∼ 90 mTorr argon plasma gas presure assuming that the Boltzmann distribution and at the 20 W ∼ 80 W RF input power, the experiment was conducted. When the 2∶ 1 transformer is used, the secondary transformer coil current transferred to the plasma is doubled so the plasma density is increased at the same power range. We can consider the power balance equation that the plasma density is proportional to the input power absorbed to the plasma. The magnitude of a self-bias voltage was decreased and the plasma density was dramatically increased. This increased-ne could be understood by enhanced electron heating and reduced ion acceleration, as well as increased power transfer efficiency. This is synergetic effect on our experimental system with the step-down transformer. In conclusion, the plasma density was increased 5 % to 55 %. This research can be implemented to other plasma sources.