Plasma processing apparatus and plasma processing method
The present invention provides a plasma processing apparatus and a plasma processing method which improve the uniformity and accordingly the yield in an etching treatment of a sample. In the plasma processing apparatus or the plasma processing method for treating a wafer placed on an upper surface of a sample table disposed in a treatment chamber in a vacuum container by using plasma generated in the treatment chamber, inductance of the coil is adjusted according to magnitude of an phase difference of the high frequency power flowing through the power supply path such that the voltage of the high frequency power becomes a maximum value or a minimum value, in which the coil is in a connection path that electrically connects, via the coil, positions between each electrode and each matching box on a plurality of power supply paths that electrically connect a plurality of electrodes and a plurality of electrodes high frequency power sources which supply high frequency power to the plurality of electrodes disposed at a center part and an area on an outer peripheral side of the center part in the sample table.
1. A plasma processing method for treating a wafer placed on an upper surface of a sample table by using plasma generated in a treatment chamber of a plasma processing apparatus,
the plasma processing apparatus including
a vacuum container that includes the treatment chamber therein;
the sample table that is disposed in the treatment chamber and having the upper surface upon which a wafer to be treated is placed;
two electrodes that are disposed in a film being made of dielectric material and which form the upper surface of the sample table, and which are disposed at a lower side of a center part and an area on an outer peripheral side of the center part on the upper surface of the sample table, respectively;
two high frequency power sources that supply high frequency power to said two electrodes, respectively;
two matching boxes that are each respectively disposed on two power supply paths that electrically connect said two electrodes and the two high frequency power sources, respectively; and
a connection path that electrically connects positions between each said matching box on each said power supply path and each said electrode via a coil, the method comprising:
adjusting an inductance of the coil according to a magnitude of a phase difference between the high frequency power flowing through each of said two power supply paths which is obtained by using a result of detection of a magnitude of a voltage or a current of the high frequency power flowing through each of said two power supply paths during treating of the wafer, the inductance of the coil being adjusted such that the voltage of the high frequency power flowing through one of said two power supply paths becomes a maximum value or a local minimum value.
2. The plasma processing method according to claim 1 ,
wherein the two electrodes, the two power supply paths, and the connection path configure a resonance circuit by adjusting the inductance of the coil.
3. The plasma processing method according to claim 1 ,
wherein said adjustment is performed such that in a case where the phase difference is within a range from −90 degrees to 90 degrees, the inductance of the coil is adjusted so that the minimum value is detected, and in a case where the phase difference is within a range from 90 degrees to 180 degrees or from −90 degrees to −180 degrees, the inductance of the coil is adjusted so that the maximum value is detected.
4. The plasma processing method according to claim 1 ,
wherein the two electrodes are disposed in the center part and an area surrounding the outer peripheral side of the center part in a ring shape, respectively.