APPARATUS FOR PLASMA PROCESSING AND METHOD OF ETCHING

In an apparatus for plasma processing according to an exemplary embodiment, a radio frequency power source generates radio frequency power which is supplied for generation of a plasma. A bias power source supplies bias power to a lower electrode of a substrate support. The bias power varies a potential of a substrate within a cycle thereof. The radio frequency power is supplied in at least a part of a first period in the cycle, in which the potential of the substrate is relatively high. A power level of the radio frequency power is lowered in a second period in the cycle, in which the potential of the substrate is relatively low. In the first period and the second period, the sheath adjuster adjusts a position in a vertical direction of an upper end of a sheath above an edge ring.