Patent ID: 8080126

Claim:
A plasma processing apparatus comprising: a chamber configured to be maintained at a reduced pressure; an upper electrode and a lower electrode arranged to be opposed to each other in the chamber, wherein: a substrate to be processed is held on an opposing face of the lower electrode, and the upper electrode has an electrode supporting member, and an electrode plate arranged to be opposed to the lower electrode, the electrode plate to be exposed to plasma being disposed on a lower surface of the electrode supporting member, and having a ring-shaped outer portion constituted by a conductor or semiconductor and a central portion formed of a high resistance member with higher resistivity than that of the outer portion; a process gas source connected to the chamber, and a high frequency electric power source configured to provide high frequency electric power within a range of 27 MHz to 60 MHz from a face of the upper electrode to which the lower electrode is opposed in order to form a high frequency electric field between the upper and the lower electrodes to generate a plasma of the process gas, wherein a predetermined plasma processing is performed on the substrate to be processed with the plasma, and wherein the central portion of the electrode plate, which is formed of the high resistance member, has a skin depth δ expressed by the following formula that is larger than the central portion of the electrode plate in thickness: δ=(2/ωσμ) 1/2 , where ω=2πf (f is frequency), σ is conductivity, and μ is magnetic permeability.