Patent ID: 7828927

Claim:
A plasma processing device for performing a process on a substrate by subjecting the substrate to be exposed to a plasma generation region, the device comprising: a chamber for accommodating therein the substrate; a dielectric top plate being a part of a partition wall of the chamber; an antenna unit comprising a slot antenna, for supplying a high frequency electromagnetic field through the top plate into the chamber to form the plasma generation region between the top plate and the substrate accommodated in the chamber; and a ring-shaped dielectric delay pass unit for branching the high frequency electromagnetic field propagating through the top plate, wherein when the branched high frequency electromagnetic field again joins with the high frequency electromagnetic field that propagates through the top plate without being branched, the delay pass unit shifts a phase of the branched high frequency electromagnetic field by an odd multiple of λ,/2 compared with that of the high frequency electromagnetic field that propagates through the top plate without being branched to decrease the electromagnetic field at a location near a peripheral end of the top plate, where λ is a wavelength of the high frequency electromagnetic field propagating through the top plate, and wherein the delay pass unit is protruded from the top plate in a direction perpendicular to a propagating direction of the high frequency electromagnetic field that propagates through the top plate without being branched and the delay pass unit does not contact the plasma generation region, and wherein the delay pass unit is disposed beyond the periphery of the slot antenna.