Microwave plasma processing apparatus and microwave plasma processing method

A microwave plasma processing apparatus comprising:

• a chamber that accommodates a workpiece;
• a microwave generating source that generates microwaves;
• a waveguide unit that guides the microwaves generated from the microwave generating source toward the chamber;
• a planar antenna made of a conductor having a plurality of slots that radiate the microwaves guided by the waveguide unit toward the chamber;
• a microwave-transmitting plate made of a dielectric material that constitutes a top wall of the chamber and transmits the microwaves radiated from the plurality of slots;
• a gas supply mechanism that supplies a gas into the chamber;
• and
• an exhaust mechanism that exhausts an atmosphere in the chamber,
• wherein the planar antenna includes a plurality of slot groups each forming one unit including one or more of the slots, and
• the slots are formed so as to form an odd number of slot groups equal to or more than three in a circumferential direction.