| 摘要 |
An electron beam projection system comprises a source of an electron beam, a first doublet of condenser lenses with a first symmetry plane, a first aperture comprising a trim aperture located at the first symmetry plane of the first doublet also serving as a first blanking aperture. A second aperture comprises a shaping aperture located below the trim aperture. A second doublet of condenser lenses with a second symmetry plane is located below the second aperture, the second doublet having a symmetry plane. A third aperture is located at the symmetry plane of the second doublet wherein the third aperture comprises another blanking aperture. There are first blanking plates between the first condenser lens and the trim aperture, and second electrostatic alignment plates between the trim aperture and the second aperture. The second doublet comprises a pair of illuminator lenses including deflectors coaxial therewith and located inside the radius of the lenses and shielding rings located along the inner surfaces of the lenses, and correctors located coaxial with the deflectors and inside or outside of the radii thereof including stigmators, focus coils and a hexapole.
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