A plasma source for a substrate is provided. The plasma source may include a source electrode and an impedance box. The source electrode receives a source Radio Frequency (RF) from the external and generates plasma based on capacitive coupling within a vacuum chamber. The impedance box connects at one end to an outer circumference surface of the source electrode, and is grounded at the other end to the vacuum chamber, and controls an electric current flowing from the source electrode to the vacuum chamber by the source RF.