Plasma processing apparatus

A plasma processing apparatus, comprising:

• a processing chamber having a ceiling and a sidewall;
• a susceptor, disposed in the processing chamber, for mounting thereon an object to be processed;
• a processing gas supply mechanism for supplying a processing gas through the ceiling to generate a plasma;
• a gas exhaust unit for exhausting a gas from under the susceptor;
• and
• a fin structure having plural fins arranged at regular intervals, which is disposed as protruded from the sidewall in a region extending from a top end portion of the sidewall to a region positioned lower than a mounting surface of the susceptor for mounting the object thereon.

A plasma processing apparatus, comprising:

• a plasma diffusion preventing member in a processing chamber for generating a plasma,
• wherein the plasma diffusion preventing member includes:
• a plate-shaped upper part having a plurality of openings, which is disposed at an upper flow side of a plasma diffusion path;
• a plate-shaped lower part having a plurality of openings, which is disposed at a lower flow side of the plasma diffusion path;
• and
• side surfaces that are coupled to the upper part and the lower part to provide an enclosed space,
• wherein the upper part, the lower part, and the side surfaces are formed of a conductive material, so that they are electrically connected to each other, thereby having a same potential.