Magnetic filter for ion source

摘要

A magnetic filter (90) for an ion source (26) is provided. The ion source comprises a housing defining a plasma confinement chamber (76) in which a plasma including ions is generated by ionizing a source material. The housing includes a generally planar wall (50) in which are formed a plurality of elongated apertures (64) through which an ion beam (84) may be extracted from the plasma. The plurality of elongated openings are oriented substantially parallel to each other and to a first axis (66) which lies within the planar wall, the first axis being substantially orthogonal to a second axis (68) which also lies within the planar wall. The magnetic filter (90) is disposed within the plasma confinement chamber (76). The magnetic filter separates the plasma confinement chamber into a primary region (86) and a secondary region (88). The magnetic filter comprises a plurality of parallel elongated magnets (90a-90n), oriented at an angle &thetas; as measured from the second axis (68), and lying in a plane which is generally parallel to the generally planar wall (50). <IMAGE>