Patent ID: 7230256

Claim:
An ion doping system comprising: a chamber; an exhausting section for exhausting gases from the chamber; an ion source, which is provided for the chamber, includes an inlet port to introduce a gas including a dopant element, a filament emitting thermo electrons, and an anode electrode to produce an arc discharge between the filament and the anode electrode, and decomposes the gas through the arc discharge, thereby generating a plurality of ion species including the dopant element; and an accelerating section for extracting the plurality of ion species, generated in the ion source, from the ion source and accelerating the plurality of ion species toward a target, wherein the ion doping system controls the arc discharge such that a generation ratio of the plurality of ion species is kept constant in the ion source by maintaining an amount of arc current between the filament and the anode electrode at a constant value, while allowing a current density of an ion beam to change.