Plasma processing apparatus

An apparatus for generating a plasma by an electron cyclotron resonance and processing a substrate by using this plasma, comprising:

• a processing chamber;
• means for setting said chamber in a vacuum atmosphere;
• a support table disposed in said chamber, said support table having a support surface for supporting the substrate, and said chamber defining a discharge space above said support surface;
• gas supplying means for supplying a processing gas to be converted into the plasma in said chamber;
• first and second magnetic poles respectively located on upper and lower sides of the discharge space, and both located outside said chamber, in order to form a magnetic field in the discharge space;
• means for adjusting the strength of the magnetic field;
• a microwave transmission window formed in said chamber to oppose the discharge space;
• a first conductive plate arranged on said microwave transmission window outside said chamber,
• a plurality of slits formed in said first conductive plate and serving as microwave inlet ports;
• a dielectric plate adjoining said first conductive plate;
• a second conductive plate adjoining said dielectric plate with no gap therebetween;
• and
• microwave supply means for supplying a microwave to said first conductive plate, and comprising a coaxial line constituted by a central conductor and an outer conductive pipe, an end of said central conductor being guided to a central portion of an upper surface of said dielectric plate without contacting said second conductive plate so as to form transmission paths of the microwave from the central portion to peripheral portions in said dielectric plate.