Compensation of space charge for positive ion beams using electron injection and confinement in nonuniform magnetic fields

Abstract – Transportation of a low energy ion beam, as required by advanced implantation systems, is difficult due to space charge that makes the beam to diverge. Compensation of space charge may be obtained through electron injection and confinement. The article presents the computer simulated results obtained with the OPERA3D/TOSCA/SCALA commercial software package.

It has been shown that electrons injected in the regions of nonuniform magnetic fields around dipoles and other magnets that are used for ion beam control exhibit helical trajectories which can be confined inside curved “magnetic bottles.” An optimal range of positions for placing electron sources with respect to the magnet has been shown to exist.

The full paper is avaiable at Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures.