Plasma processing apparatus and method

A plasma processing method in a plasma processing apparatus, wherein the plasma processing apparatus includes

• a process container that forms a process space to accommodate a target substrate,
• a vacuum pump connected to an exhaust port of the process container to vacuum-exhaust gas from inside the process container,
• a first electrode and a second electrode disposed opposite each other within the process container, the first electrode being an upper electrode and the second electrode being a lower electrode and configured to support the target substrate through a mount face,
• a first radio frequency (RF) power supply configured to apply a first RF power to the first electrode or the second electrode,
• a second RF power supply configured to apply a second RF power to the second electrode, the second RF power having a frequency lower than that of the first RF power,
• a direct current (DC) power supply configured to apply a DC voltage to the first electrode,
• a process gas supply source configured to supply a process gas into the process container, and
• a conductive member disposed above the second electrode, as a ring around the first electrode, to be exposed to plasma within the process space, and
• wherein the plasma processing method includes executing an etching process that comprises:
• supplying an etching gas as the process gas into the process container in which the target substrate is supported on the second electrode;
• applying an RE power for plasma generation as the first RE power and applying an RE power for ion attraction as the second RE power to turn the etching gas into plasma and to subject the target substrate to etching;
• applying a negative DC voltage to the first electrode during the etching to increase an absolute value of self-bias on the first electrode;
• and
• releasing DC electron current generated by the negative DC voltage to ground through plasma and the conductive member, by using a first state where the conductive member is connected to a ground potential portion.