Patent ID: 7243610

Claim:
A plasma device characterized by comprising: a cavity for forming a resonator and outputting by converting the fed high frequency electromagnetic field into a rotating electromagnetic field; a waveguide consisting of a first conductive plate in which said cavity opens and a second conductive plate in which a plurality of slots are formed opposing said first conductive plate; a ring member which is formed externally around an opening of said cavity in said first conductive plate and is disposed within the waveguide, has an inner diameter which is the same as that of said cavity, and protrudes from said first conductive plate toward said second conductive plate; and a processing vessel, in which a plasma is generated by the high frequency electromagnetic field supplied from said cavity through said waveguide; wherein the cavity is formed of a circular conductor member connected to an outer conductor of a coaxial waveguide for feeding the high frequency electromagnetic field and a cylindrical conductor member having one end connected to the circular conductor member and the other end that opens in the waveguide, wherein a feeding pin is provided at a position separate from a center of the circular conductor member in a radial direction thereof and having one end connected to an inner conductor of the coaxial waveguide, and wherein a perturbation pin is provided at a position that forms a predetermined angle with the feeding pin through the center of the circular conductor member and having one end connected to the circular conductor member.