Plasma processing apparatus and method

A plasma processing method for use with a plasma processing apparatus which includes a depressurizable processing chamber;

• a lower electrode provided in the processing chamber and serving as a mounting table for mounting thereon a target object to be processed;
• a facing electrode, serving as an upper electrode or an antenna electrode, provided in the processing chamber so as to be opposite to the lower electrode;
• a gas supply source for introducing a gas including a halogen-containing gas and an oxygen gas into the processing chamber;
• and a plasma generation unit for generating a plasma of the gas including the halogen-containing gas and the oxygen gas in the processing chamber, the plasma processing method comprising:
• introducing the gas including the halogen-containing gas and the oxygen gas from the gas supplying source into the processing chamber in which, among inner surfaces of the processing chamber which are exposed to the plasma of the gas including the halogen-containing gas and the oxygen gas, at least a part of or all of the surfaces between a mounting position of the target object and the facing electrode;
• or at least a part of or all of the surfaces of the facing electrode are coated with a fluorinated compound;
• generating the plasma of the gas including the halogen-containing gas and the oxygen gas by using the plasma generation unit;
• and
• performing a plasma processing on the target object mounted on the mounting table by an action of the plasma of the gas including the halogen-containing gas and the oxygen gas,
• wherein a material forming the fluorinated compound contains YF3, and
• wherein an outermost layer of the fluorinated compound is transformed into a transformed layer containing Y, O and F or containing Y, O, F and at least one of Cl and Br by the plasma of the gas including the halogen-containing gas and the oxygen gas.