Plasma processing apparatus

A plasma processing apparatus, comprising:

• a chamber being possible to maintain an atmosphere more depressurized than atmospheric pressure;
• plasma generator generating a plasma inside the chamber;
• a gas supplier supplying a gas into the chamber;
• a placement part, the placement part being positioned below a region where the plasma is generated, a processed product being placed on the placement part;
• a depressurization part depressurizing inside of the chamber;
• and
• a power supply electrically connected to an electrode, the electrode being provided on the placement part via a bus bar,
• the bus bar being formed of an alloy of copper and gold, the alloy of copper and gold being exposed on a surface of the bus bar, the gold being more included than the copper on a surface side of the bus bar, the copper being more included than the gold on a center side in a thickness direction of the bus bar, or
• the bus bar including a first layer formed of the copper and a second layer covering the first layer and being formed of an alloy of the copper and the gold, the alloy of copper and gold being exposed on a surface of the second layer, the gold being more included than the copper on a surface side of the second layer, the copper being more included than the gold on a side of the first layer of the second layer;
• wherein the plasma processing chamber is further comprising:
• a supporting part supporting the placement part in an internal space of the chamber, the supporting part including
• a mounting part positioned below the placement part and provided with the placement part, and
• a beam extending inside the chamber from a side surface of the chamber toward a center axis of the chamber, one end of the beam being connected to a side surface of the mounting part, an internal main space of the beam being connected to an outside space of the chamber,
• a thickness of a side part on the placement part side of side parts of the beam is as t1, the placement part side of side parts of the beam is from a top of the internal main space to a top of the beam, t1 is 14 mm to 18 mm,
• a thickness of a side part on an opposite side of the placement part of the beam is t2, the opposite side of the placement part side of the beam is from a bottom of the internal main space to a bottom of the beam, t2 is 8 mm to 10 mm,
• a distance between an outer wall of the chamber and the center axis of the chamber is L, L is 260 to 350 mm, and
• a weight of the placement part is W, W is 56 to 70 kgf (weight kilogram).