Patent ID: 7934468

Claim:
A plasma processing apparatus, comprising: a plurality of waveguides through which microwaves are transmitted and wherein each waveguide is disposed so that an end surface of each of the plurality of waveguides faces opposite to an end surface of another waveguide; a slot antenna that includes a plurality of slots adjacent to the waveguide, through which the microwaves propagated via the waveguides are passed; a first wavelength-varying substance partially filling an inside of the waveguide, which alters a guide wavelength λg of the microwaves to a first wavelength; a second wavelength-varying substance extending inside the waveguide over an area located between an end surface of the waveguide, where the microwaves are reflected, and a line extending from a center of a slot in the slot antenna closest to the end surface, which alters the guide wavelength λg of microwaves transmitted through the area to a second wavelength smaller than the first wavelength; a plurality of dielectric members disposed adjacent to the slot antenna, through which the microwaves that passed through the plurality of slots at the slot antenna are transmitted; and a processing chamber where a subject to be processed is processed by plasma generated with a gas excited by the microwaves transmitted through the plurality of dielectric members.