To provide an ion source for ion implanting equipment enabling to have very high ionization efficiency, by generating a powerful and uniform magnetic field in an ionization room, and by maintaining it.
The ion source is constituted with an ionization room with an opening 18, partially divided with a wall, and along the path of which an ion beam is extracted and a magnet assembly 45 with, a yoke 46 of the closed form surrounding the whole ionization room in which at least one of coils 49, 51 is twisted around the yoke. The yoke 46 has, generally, a troidal shape and includes a pair of opposite magnetic poles 48a, 48b. Most of magnetic line of flux generated by the coils during operation of the ion source, comes out from the 1st opposite magnetic pole 48a, and passes through the ionization room, and goes into the 2nd opposite magnetic pole 48b. A floating magnetic field generated from the magnet assembly 45 directs in the direction which intersects perpendicularly with the path of the ion beam extracted from the opening 18, and becomes comparatively uniform in the interior of the ionization room.
HORSKY THOMAS N
TRUEIRA FRANK RAYMOND
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