Image Number 13 for United States Patent #8038836.
A plasma processing apparatus includes a barrier wall member disposed between a plasma generation chamber and a processing chamber to separate the plasma generation chamber from the processing chamber. The barrier wall member assumes a fin structure achieved by disposing in a radial pattern numerous plate-like fin members extending from a central area thereof toward a peripheral edge. An upper end portion of each fin member overlaps a lower end portion of an adjacent fin member. The fin members are disposed with gaps formed between them and are made to range upward with a tilt along the circumferential direction.