| 摘要 |
PROBLEM TO BE SOLVED: To minimize an RF power loss and its machine difference (variation among devices) in a filter circuit for attenuating undesired high-frequency noise, and to improve reproducibility and reliability for process performance.SOLUTION: In this plasma etching device, first stage air-core coil units A(1) and A(2) of two systems provided on first and second power feeding lines are concentrically attached to a bobbin 114A. That is, coil lead wires respectively configuring both air-core coil units A(1) and A(2) are wound in spiral at an equal coil length while overlapping with each other and being translated in an axial direction. Similarly, respective coil lead wires of second stage air-core coil units B(1) and B(2) are wound in spiral at an equal coil length while overlapping with each other and being translated in the axial direction. |
