Patent ID: 7718978

Claim:
An ion source which generates an ion beam having a shape where a dimension in an X direction in a plane intersecting with a traveling direction is larger than a dimension in a Y direction perpendicular to the X direction, wherein said ion source comprises: a plasma generating chamber which is a chamber that functions also as an anode, and that is used for internally generating a plasma, said chamber having an ion extraction port extending in the X direction; a magnet which generates a magnetic field extending along the X direction, in said plasma generating chamber; indirectly-heated cathodes which are placed respectively on both sides of said plasma generating chamber in the X direction, and which are used for generating the plasma in said plasma generating chamber, and increasing or decreasing a density of a whole of the plasma; and plural filament cathodes which are juxtaposed in the X direction in said plasma generating chamber, and which are used for generating the plasma in said plasma generating chamber, and controlling a density distribution of the plasma.