| 摘要 |
Stages are disclosed for holding, e.g., a reticle or substrate while performing charged-particle-beam (CPB) lithography involving the reticle or substrate. The subject stages include at least one linear motor and exhibit reduced adverse effects at an optical axis of magnetic fields generated by the linear motor(s). In one configuration, a stage-driving permanent magnet is split into two magnet subunits that are situated equidistantly from the optical axis. This configuration allows each of the subunits to be situated farther from the optical axis than the single magnet used in a conventional stage. Because the magnitude of a magnetic field generated by a permanent magnet generally is inversely proportional to the square of the distance from the permanent magnet, increasing the distance of the magnet from the optical axis reduces the magnitude of the magnetic field, generated by the permanent magnet, at the optical axis. Various symmetrical configurations of magnet subunits, and of magnet subunits with associated dummy permanent magnets are disclosed.
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