Plasma processing apparatus and plasma processing method

Abstract

In an outer peripheral portion of a wafer, a circumferential variation in a microwave electric-field intensity is minimized, and circumferential uniformity of plasma processing is improved. A plasma processing apparatus includes a circular waveguide, a 90° phase difference plate for the microwaves is provided from above the inside of the circular waveguide, a 180° phase difference plate is provided below the 90° phase difference plate, a rotation drive mechanism is further connected to the 180° phase difference plate. a detector configured to detect a variation in an electric-field intensity in a circumferential direction is connected to a lower portion of the 180° phase difference plate, and a control unit configured to adjust a rotation angle of the 180° phase difference plate to minimize deterioration of axial symmetry of the electric-field intensity detected by the detector.

Dependencies are inferred from the claim text.