PLASMA PROCESSING APPARATUS
A uniform plasma processing to a sample is performed by adjusting the distribution of the induced magnetic field in an inductively-coupled-plasma processing apparatus and correcting the plasma distribution on the sample. Between an induction coil and a dielectric window a conductor is provided along the induction coil and side by side with at least a part of the induction coil in its circumferential direction. The conductor is set up at a location where the intensity of the induced magnetic field generated from the induction coil is wished to be weakened and the relationship of Lp≧Lr is satisfied, letting the shortest distance from the induction coil to the surface of the conductor be Lr and letting the shortest distance from the induction coil to the plasma generated directly under the dielectric window be Lp.
1 . A plasma processing apparatus, comprising:
a vacuum processing chamber in which a plasma processing is applied to a sample;
a dielectric window which forms an upper surface of said vacuum processing chamber;
a gas-introducing unit for introducing a gas into said vacuum processing chamber;
a sample stage which is deployed in said vacuum processing chamber for mounting said sample thereon;
an induction coil which is provided over said dielectric window;
a radio-frequency power-supply for supplying a radio-frequency power to said induction coil; and
a conductor which is set up between said induction coil and said dielectric window, is electrically connected in a full circle so that an induced current can be formed, is provided side by side with at least a part of said induction coil in its circumferential direction along said induction coil, and is set up at a location where intensity of an induced magnetic field generated from said induction coil is wished to be weakened and relationship of Lp≧Lr is satisfied letting the shortest distance from said induction coil to surface of said conductor be Lr and letting the shortest distance from said induction coil to a plasma generated directly under said dielectric window be Lp.
2 . The plasma processing apparatus according to claim 1 , wherein
said conductor is of a ring shaped conductor.
3 . The plasma processing apparatus according to claim 2 , wherein
said ring-shaped conductor is provided off a center of said induction coil.
4 . The plasma processing apparatus according to claim 1 , further comprising a Faraday shield to which said conductor is electrically connected.
5 . The plasma processing apparatus according to claim 1 , further comprising a Faraday shield which includes a plurality of radial slits; and
wherein said conductor is formed by modifying shape of one of slits of said Faraday shield.
6 . The plasma processing apparatus according to claim 1 , wherein
said induction coil is a circular coil which is wound in a single turn and whose electric-feeding ends are partially overlapped with each other, and
said conductor is positioned under said electric-feeding ends of said induction coil.
7 . A plasma processing apparatus, comprising:
a vacuum vessel comprising a top board which is formed of an insulating material which can pass through electromagnetic waves;
an induction antenna deployed opposing to said top board, an induced magnetic field from which is used to generate a plasma in said vacuum vessel; and
induced-magnetic-field attenuation means for partially cancelling out said induced magnetic field, deployed at an arbitrary position within said top board's pass-through surface and between said induction antenna and surface of said plasma directly under said top board.