| 摘要 |
<p>According to a known projection lithography method an object (14) is imaged on an imaging surface (16) by means of a telescopic system of rotationally symmetrical electron lenses (10, 12). The throughput during the production of integrated circuits by means of projection lithography is determined by the amount of current in the imaging electron beam; this current is subject to a limit which is imposed by the resolution-limiting interaction of the electrons (Coulomb interaction). The invention allows for a larger beam current in that areas (18) with a high current concentration are avoided. To this end, the imaging system includes two quadrupoles, each of which coincides with one of the two round lenses (10, 12), so that the electrons are concentrated in line-shaped focal spots instead of a (small) circular cross-over (18). The system remains telescopic to a high degree and the imaging remains stigmatic.</p> |
