| 摘要 |
A collimator magnet (CM) usable in an ion implantation system provides an exit ion beam with a large aperture, substantially parallel in one plane or orthogonal planes. The CM includes identical poles, defined by an incident edge receiving an ion beam, and an exit edge outputting the ion beam for implantation. Ion beam deflection takes place due to magnetic forces inside the CM and magnetic field fringe effects outside the CM. The CM incident and/or exit edge is shaped by solving a differential equation to compensate for magnetic field fringe effects and optionally, space charge effects and ion beam initial non-parallelism. The CM shape is obtained by imposing that the incidence or exit angle is substantially constant, or, incidence and exit angles have opposite sign but equal absolute values for each ray in the beam; or the sum of incidence and exit angles is a constant or a non-constant function.
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