Plasma processing apparatus and method for adjusting plasma density distribution

A plasma processing apparatus in which microwaves supplied from a coaxial waveguide having an inner conductor and an outer conductor are introduced into a processing container via a wavelength-shortening plate, a process gas is plasmatized in the processing container, and a substrate is processed using the plasma,

• wherein a dielectric member is disposed on the wavelength-shortening plate at a connecting area between the coaxial waveguide and the wavelength-shortening plate;
• and
• the dielectric member on the wavelength-shortening plate is disposed to surround a part of a circumference of the inner conductor, and can be moved to and disposed at any position around the circumference of the inner conductor,
• wherein the plasma density is lower at the area corresponding to the dielectric member than at the area not corresponding to the member.

A plasma processing apparatus comprising:

• a processing container into which a wafer is carried;
• a gas path through which a gas is supplied into the processing container;
• a transmission window which is air-tightly disposed in an opening of an upper portion of the processing container using a sealing member and transmits microwaves;
• a planar antenna member which is disposed above the transmission window;
• a wavelength-shortening plate which is disposed on an upper surface of the planar antenna member and shortens the wavelength of the microwaves;
• a conductive cover which covers the wavelength-shortening plate;
• a coaxial waveguide which is connected to the cover and has an inner conductor and an outer conductor:
• and
• a dielectric member which surrounds a part of the circumference of the inner conductor, and is disposed on a part of the wavelength-shortening plate at a connecting area between the coaxial waveguide and the wavelength-shortening plate and can be moved to and disposed at any position along and around a circumference of the inner conductor.