Patent ID: 7478609

Claim:
A plasma processing apparatus having a processing chamber for performing processing using plasma therein and microwave introduction means for introducing microwaves into said processing chamber to cause a reactant gas supplied in said processing chamber to attain a plasma state, wherein said microwave introduction means includes a dielectric member transmitting said microwaves, each said dielectric member having a shape in cross section in a direction approximately perpendicular to a transmitting direction of said microwaves through said dielectric member that allows transmission of said microwaves of substantially a single mode, and each said dielectric member having a thickness T in said transmitting direction that satisfies a condition of (λ×(2 m+0.7)/4)≦T≦(λ×(2 m+1.3)/4), where λ is a wavelength of said microwaves of the single mode transmitted through said dielectric member and m is an arbitrary integer, wherein the wavelength of the microwaves of the single mode is, λ=(λ 0 /SQRT (∈ r ))/ SQRT{ 1−(λ 0 /SQRT (∈ r )) 2 /2×((7/ L 1) 2 +(1/ L 2) 2 )} where λ 0 : wavelength of the microwaves propagating in a free space in the air or a vacuum; ∈ r : relative dielectric constant of the dielectric member; L 1 : length of the longer side of the dielectric member in cross section; and L 2 : length of shorter side of the dielectric member in cross section, wherein said microwave introduction means also includes slot antenna plates attached on a side of each said dielectric member that is opposite from the processing chamber, wherein a side of each said dielectric that faces the processing chamber is arranged to face a substrate located in the processing chamber such that at least one slot of the respective slot antenna plate is in a direct path of microwaves transmitted to said substrate, said substrate thereby being the subject of said processing.