| 摘要 |
<p>A system to control the focus of a mask-less lithographic apparatus, the apparatus including a projection system to project an image of a programmable patterning device onto a substrate. A first actuator system is configured to move at least one of the lenses of the projection system in a direction perpendicular to the optical axis of the projection system. A radiation beam expander is configured to project an image of the programmable patterning device onto the at least one lens. A second actuator system is configured to move the radiation beam expander in a direction parallel to the optical axis of the projection system in order to control the focus of the image projected onto the substrate.</p> |
