Patent ID: 8858712

Claim:
An electrode for use in a plasma processing apparatus, the electrode being provided above a lower electrode within a processing chamber of the plasma processing apparatus so as to face the lower electrode serving as a mounting table configured to mount thereon a processing target substrate, the electrode comprising: an upper member provided with a plurality of gas passage holes through which a processing gas is supplied; a lower member positioned below the upper member and provided with multiple sets of gas discharge holes through which the processing gas is discharged; and an intermediate plate-shaped member positioned between the upper member and the lower member and provided with a plurality of circular communication holes through the plate-shaped member through which the gas passage holes and the gas discharge holes are allowed to communicate with each other, wherein each communication hole through the plate-shaped member is coaxially aligned with a respective one of the plurality of gas passage holes, and wherein each gas passage hole has a diameter larger than that of each gas discharge hole, each communication hole has a diameter larger than that of each gas passage hole, each set of the gas discharge holes communicates with corresponding one of the gas passage holes via corresponding one of the communication holes, and each set of the gas discharge holes is arranged only outside of a perimeter of the corresponding one of the gas passage holes and inside of a perimeter of the corresponding one of the communication holes when viewed from a top thereof, wherein each gas discharge hole has a constant diameter along an entire thickness of the lower member, an upper part of the each gas discharge hole adjacent the intermediate plate-shaped member is inclined with respect to upper and lower surfaces of the lower member, and a lower part of the each gas discharge hole is substantially perpendicular to upper and lower surfaces of the lower member, so that electrons or ions are suppressed from being introduced into the electrode, and in each set of the gas discharge holes, the upper part of each gas discharge hole is inclined radially outward from a common axis of the corresponding one of the gas passage holes and the corresponding one of the communication holes that are in communication with the gas discharge holes of the set, and the set of gas discharge holes is arrayed annularly around said common axis.