Plasma processing apparatus and method for controlling the same
View Patent ↗A method for controlling a plasma processing apparatus which includes a vacuum vessel, a first, second and third RF power supply, a first and second electrode, and a phase control unit for controlling a phase difference between a second RF voltage from the second RF power supply and a third RF voltage from the third RF power supply. The controlling method includes the steps of supplying a predetermined power from the first RF power supply to ignite plasma, after confirming ignition of plasma, supplying a predetermined power respectively from the second RF power supply and the third RF power supply, and when starting power supply from the second RF power supply and the third RF power supply, fixing the phase to a predetermined phase angle using a preset mode without carrying out phase control, and after a matching operation has stabilized, starting the phase control.
1. A method for controlling a plasma processing apparatus that comprises:
a vacuum vessel in which plasma is generated;
a first RF power supply, a second RF power supply and a third RF power supply provided outside the vacuum vessel;
a first electrode disposed either inside or outside the vacuum vessel to which a first RF voltage from the first RF power supply is supplied;
a second electrode disposed inside the vacuum vessel, having an upper surface on which a sample is mounted, and to which a second RF voltage from the second RF power supply is supplied;
an RF radiation unit other than the second electrode that is capacitively coupled with the plasma generated inside the vacuum vessel to which a third RF voltage from the third RF power supply is supplied;
means for detecting a potential of the RF being transmitted through the plasma at an inner wall surface of the vacuum vessel;
means for detecting an emission status of the plasma within the vacuum vessel;
and
a phase control unit for controlling a phase difference between the second RF voltage and the third RF voltage from the third RF power supply;
wherein the controlling method comprises the steps of:
controlling the phase difference between the RF voltage of the second electrode and the third RF voltage having a same frequency using a signal source other than a phase signal, disposed between the second electrode and the RF radiation unit that is capacitively coupled with the plasma;
wherein when removing a deposition film inside the vacuum vessel, controlling the phase difference according to an amount of the deposition film; and
wherein the signal source other than the phase signal includes one of an RF voltage, a plasma emission, and a combination of the RF voltage and the plasma emission.