Plasma processing apparatus
The disclosed plasma processing apparatus includes a chamber, a substrate support, a radio frequency power source, and a bias power source. The radio frequency power source generates radio frequency power to generate plasma. The bias power source is connected to a bias electrode of the substrate support, and generates an electric bias. An edge ring mounted on the substrate support receives a part of the electric bias through an impedance adjuster or receives another electric bias. An outer ring extends outside the edge ring in a radial direction, and receives a part of the radio frequency power or other radio frequency power.
1. A plasma processing apparatus comprising:
a chamber;
a substrate support having a conductive base and an electrostatic chuck on the conductive base, the conductive base configuring a bias electrode, and the electrostatic chuck including a substrate placing region to support a substrate placed thereon and an edge ring placing region to support an edge ring placed thereon, the edge ring placing region surrounding the substrate placing region;
an insulating member surrounding the substrate support;
a radio frequency power source configured to generate radio frequency power that is supplied to the conductive base to generate plasma above a substrate supported by the substrate support in the chamber, the radio frequency power source being connected to the conductive base through an electrical path;
a bias power source connected to the conductive base through the electrical path;
a first electrode disposed in the edge ring placing region of the electrostatic chuck and capacitively coupled with the edge ring placed on the edge ring placing region;
a second electrode disposed in the insulating member and capacitively coupled with an outer ring placed on the insulating member, the outer ring extending outside the edge ring in a radial direction;
a first impedance adjuster electrically connected between the conductive base and the first electrode or between the electrical path and the first electrode, and providing variable impedance between the conductive base and the edge ring or between the electrical path and the edge ring; and
a second impedance adjuster electrically connected between the electrical path and the second electrode and providing variable impedance between the electrical path and the outer ring.
2. The plasma processing apparatus according to claim 1 , further comprising:
a filter connected between the second impedance adjuster and the second electrode,
wherein the filter has a frequency characteristic that selectively passes the radio frequency power with respect to an electric bias that is supplied from the bias power source to a lower electrode.