Plasma processor

Claim 1

A method of determining the shapes of reflecting surfaces of a sub reflector and a main reflector in a plasma processor the plasma processor including a plasma generation portion in which an electron cyclotron resonance plasma is generated, means for producing a magnetic field in the plasma generation portion for establishing the electron cyclotron resonance plasma, means for supplying gas to the plasma generation portion, means for producing microwave energy and for supplying the microwave energy to the plasma generation portion, the plasma generation portion including an inlet part for receiving microwave energy in a vacuum vessel part, the inlet part including expansion means for expanding the microwave energy received from the means for producing microwave energy, means for transmitting the microwave energy from the expansion means to the vacuum vessel part, and means for making substantially uniform the microwave energy density distribution along a radial direction in the vacuum vessel part, the expansion means and the means for making substantially uniform including the sub reflector for reflecting microwave energy from the means for producing microwave energy and the main reflector disposed in the inlet part for reflecting microwave energy into the vacuum vessel part that has been reflected by the sub reflector, the method comprising: choosing a parabolic surface as a front reflecting surface of the main reflector and determining the size of an aperture plane and a focal position of the main reflector for the chosen parabolic surface; disposing the sub reflector at the focal position of the main reflector and choosing a parabolic surface as a front reflecting surface of the sub reflector so that microwave energy reflected from an edge of the sub reflector impinges on an edge of the aperture plane; the distribution of radiant electric fields reflected by the sub reflector and the main reflector along a line perpendicular to incident microwave of examining if an energy to determine whether the distribution of microwave energy is uniform; if the distribution of microwave energy along the lien is determined not to be uniform, changing the curvature of the front surface of said sub reflector to change the parabolic shape thereof; and changing the shape of the front surface of the main reflector so that components of the microwave energy are parallel and in phase a step of repeating said fourth step through said sixth step until the radiant electrical fields become parallel and uniform.

Claim 2

A method of determining the shapes of reflecting surfaces of a sub reflector and a main reflector in a plasma processor the plasma processor including a plasma generation portion in which an electron cyclotron resonance plasma is generated, means for producing a magnetic field in the plasma generation portion for establishing the electron cyclotron resonance plasma, means for supplying gas to the plasma generation portion, means for producing microwave energy and for supplying the microwave energy to the plasma generation portion, the plasma generation portion including an inlet part for receiving microwave energy in a vacuum vessel part, the inlet part including expansion means for expanding the microwave energy received from the means for producing microwave energy, means for transmitting the microwave energy from the expansion means to the vacuum vessel part, and means for making substantially uniform the microwave energy density distribution along a radial direction in the vacuum vessel part, the expansion means and the means for making substantially uniform including the sub reflector for reflecting microwave energy from the means for producing microwave energy and the main reflector disposed in the inlet part for reflecting microwave energy into the vacuum vessel part that has been reflected by the sub reflector, the method comprising: choosing a parabolic surface as a front reflecting surface of the main reflector and determining the size of an aperture plane and a focal position of the main reflector for the chosen parabolic surface; disposing the sub reflector at the focal position of the main reflector and choosing a parabolic surface as a front reflecting surface of the sub reflector so that microwave energy reflected from an edge of the sub reflector impinges on an edge of the aperture plane; the distribution of radiant electric fields reflected by the sub reflector and the main reflector along a line perpendicular to incident microwave of examining if an energy to determine whether the distribution of microwave energy is uniform; if the distribution of microwave energy along the lien is determined not to be uniform, changing the curvature of the front surface of said sub reflector to change the parabolic shape thereof; and changing the shape of the front surface of the main reflector so that components of the microwave energy are parallel and in phase a step of repeating said fourth step through said sixth step until the radiant electrical fields become parallel and uniform.