Patent ID: 7276711

Claim:
A beam space-charge compensation device which is applied to an angular energy filter provided midway in a beam path of an ion beam processing system that performs processing by irradiating onto a wafer with an ion beam, said angular energy filter selecting only an ion species having a necessary energy from the ion beam by the use of at least a magnetic field out of an electric field and the magnetic field, wherein the beam space-charge compensation device comprises a plasma shower provided in a beam-guiding chamber of said angular energy filter for beam space-charge compensation, said plasma shower comprises an arc chamber having therein a filament for generating thermo-electrons for plasma, said arc chamber comprises an extraction hole for extracting the thermo-electrons in the generated plasma, and said plasma shower is arranged such that said extraction hole is located on lines of magnetic force, perpendicular to an ion beam advancing direction, of said magnetic field and that a center axis of said filament and a center axis of said extraction hole coincide with the lines of magnetic force, perpendicular to the ion beam advancing direction, of said magnetic field.