Patent ID: 6452338
Filing Date: 2002-09-17
Classification: H01J,H01L

Abstract:
An ion source capable of providing ions in commercial ion current levels to the ion extraction system of an ion implanter, the ion source comprising:an ionization chamber defined by walls enclosing an ionization volume, there being an elongated ion extraction aperture defining first and second axes in a side wall of the ionization chamber and a pair of aligned electron beam apertures, the ion extraction aperture having a length and width sized and arranged to enable the ion current to be extracted from said ionization volume by said extraction system; a broad beam electron gun disposed external to the ionization chamber to direct a generally dispersed beam of primary electrons through said pair of aligned electron beam apertures in the ionization chamber to a beam dump, disposed external to said ionization chamber and aligned with one of said pair of aligned election beam apertures, the beam dump being maintained at a substantial positive voltage relative to the emitter voltage of the electron beam gun, the axis of the beam path of said primary electrons extending in a direction generally perpendicular to the direction of said ion current, and parallel to one of said first or second axes of the ion extraction aperture; a vaporizer arranged to introduce a vapor into the ionization volume; and a control system enabling control of the energy of the primary electrons so that individual vapor molecules can be ionized principally by collisions with primary electrons from the electron gun.