US Patent 6884318 Plasma processing system and surface processing method

A plasma processing system in which air in a plasma processing chamber is exhausted by an exhaust unit and a microwave is supplied to the plasma processing chamber through an annular waveguide which is provided at predetermined intervals in a circumferential direction on the same plane facing a surface of an object to be processed on the plasma processing chamber side to generate plasma within the plasma processing chamber. The annular waveguide is separated into two layers of an input side waveguide and an output side waveguide. The slots are provided between these waveguides at predetermined intervals in a circumferential direction.