| 摘要 |
A magnetic lens for imaging and rotation of a charged particle beam includes a pair of focus elements axially spaced along a lens bore through which the beam passes and a rotation element positioned axially between the focus elements. Each of the lens elements includes a polepiece having opposing portions surrounding the lens bore and axially spaced apart to define a circumferential gap, and a winding for energizing the polepiece and the gap. The focus elements are energized by equal and opposite magnetic fields which focus the electron beam without substantial beam rotation. The beam can be rotated, without substantial change in focus or magnification, by varying the magnetic field of the rotation element. The lens is particularly suited for use in a shaped electron beam lithography system.
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