Plasma processing apparatus and method thereof

A plasma processing apparatus in which a processing gas is plasmatized, and blown off, so that an outer edge of a wafer, having a major surface, is subjected to plasmatizing process, said apparatus comprising:

• a nozzle head, said head being disposed on one side of said major surface, having:
• a pair of electrodes forming a gas passage passing said processing gas and plasmatizing said processing gas therebetween;
• a blow-off part being provided with a blow-off port connected to said gas passage and having a port axis which is intersected with said major surface of the wafer, said port being dimensioned small enough in diameter or in width so as not to allow said blow-off stream to be blown off directly to a part of said wafer which part is located at the more internal side of said wafer than the outer edge of said wafer and not to be subjected to plasmatizing process;
• a suction part being provided with a suction port disposed proximate to said blow-off port, said suction port forming a suction stream oriented generally in the reverse direction with respect to said blow-off stream,
• wherein the blow off stream and the suction stream are disposed on said one side of said major surface, and wherein a side periphery of a first area where the blow off stream is formed and a side periphery of a second area where the suction stream is
• formed are continued directly on said one side of said major surface;
• wherein said blow off part includes a partition wall whose one peripheral surface constitutes a peripheral surface of said blow off port and whose the other peripheral surface constitutes a peripheral surface of said suction port, said blow-off port and suction port being partitioned by said partition wall, said partition wall being dimensioned as to be reduced in thickness toward a distal end of said partition wall;
• and
• wherein a distal end of said partition wall has a knife edge-like configuration, thereby said blow-off port and suction port are generally contacted with each other at the distal edge of said partition wall.