Patent ID: 8623172

Claim:
A gas flow path structure of a substrate processing apparatus that performs a plasma process on a processing target substrate by plasma excited from a processing gas supplied between a mounting electrode and a facing electrode via a gas flow path, the substrate processing apparatus including a depressurizable processing chamber, the mounting electrode installed within the processing chamber and configured to mount the processing target substrate, and the facing electrode installed so as to face the mounting electrode and provided below the gas flow path structure, the gas flow path structure comprising: a supporting member configured to support the facing electrode while allowing the facing electrode to be movable with respect to the mounting electrode; a first displacement-absorbing pressure partition wall having a ring shape and installed at an outer peripheral portion of the supporting member so as to be concentric with the supporting member, the first displacement-absorbing pressure partition wall serving to absorb a displacement of the facing electrode with respect to a ceiling of the processing chamber at a penetration portion where the supporting member penetrates the ceiling and serving to seal an inside of the processing chamber against an ambient atmosphere around the supporting member; and a second displacement-absorbing pressure partition wall having a ring shape and installed at an outer peripheral portion of the first displacement-absorbing pressure partition wall so as to be concentric with the first displacement-absorbing pressure partition wall, wherein a first ring-shaped gas flow path is formed by the first displacement-absorbing pressure partition wall and the second displacement-absorbing pressure partition wall, the processing gas is supplied between the mounting electrode and the facing electrode via the first ring-shaped gas flow path, an upper end of the first displacement-absorbing pressure partition wall and an upper end of the second displacement-absorbing pressure partition wall are joined to the ceiling of the processing chamber, the first ring-shaped gas flow path is connected to a processing gas supply pipe that penetrates the ceiling of the processing chamber, and the processing gas moves downstream from the processing gas supply pipe to the first ring-shaped gas flow path and further downstream to a space between the mounting electrode and the facing electrode.