| 摘要 |
A wavefront modification apparatus that has a plurality of acoustic emitters, the acoustic emitters configured to emit acoustic waves which travel at least partially across a radiation beam conduit. The acoustic emitters may be configured to establish a standing acoustic wave which extends at least partially across the radiation beam conduit. The wavefront modification apparatus may be provided in a lithographic apparatus, and may be used to modify the wavefront of a radiation beam which is used by the lithographic apparatus to project a pattern onto a substrate. |
