| 摘要 |
Apparatus and methods are disclosed, in the context of charged-particle-beam microlithography, allowing increased illumination-beam current to shorten exposure time and provide good throughput, while decreasing aberrations from space-charge effects. The apparatus includes an illumination-optical system configured to shape the illumination beam to have a substantially annular transverse profile or a profile representing at least a portion of a substantially annular profile. The substantially annular profile is defined by respective concentric beam portions. The shaped illumination beam is scanned onto the reticle using a deflector in the illumination-optical system.
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