Plasma processing apparatus

A plasma processing apparatus comprising:

• a processing container formed by assembling a container upper portion having an upper side wall and a container lower portion having a lower side wall;
• a stage provided in the container lower portion of the processing container;
• and
• a peripheral introduction part configured to be an assembly, configured to be sandwiched between the upper side wall and the lower side wall, and configured to provide a plurality of gas discharge ports arranged in a circumferential direction with respect to an axis passing through a center of the stage, the assembly in which at least two members are assembled, the at least two members forming a gas flow path extending in the circumferential direction with respect to the axis in an interior thereof,
• wherein the at least two members include a first ring member and a second ring member,
• wherein the peripheral introduction part, the container upper portion and the container lower portion are thermally and electrically connected to each other,
• wherein the peripheral introduction part, the container upper portion, and the container lower portion are formed of aluminum,
• wherein an aluminum oxide film is formed on an inner wall of the gas flow path, and the plurality of the gas discharge ports communicate with a corner portion of a cross-section of the gas flow path,
• wherein the gas discharge ports are open obliquely upward from the upper portion on the inner side of the gas flow path,
• wherein the container lower portion and the second ring member are positioned by a first pin extending along the axis, and the second ring member, the first ring member, and the container upper portion are positioned by a second pin extending along the axis, and
• wherein the first pin does not penetrate the first ring member, while the second pin penetrates the second ring member.