| 摘要 |
<p>Charged particle source (14) delivers beam (20) which is collimated onto first aperture plate having first aperture (28). The beam passing therethrough is deflected by deflection plates (32, 34, 38 and 40) with respect to second aperture (46) in second aperture plate (44). The image (50) of the second aperture (46) is focused on the target plane (16) and the virtual image of the footprint (58) of the deflected beam is focused on the target plane (16). When these images overlap, a shaped beam (56) passes through. Scanning of the beam across the target plane by deflection plates (52 and 54) permits exposure of sharp-edged features (62) by positioning the image (60a) inside the margin (64) and then scanning the image (50b) thereacross to expose the sharp edge and thereupon picking up the image (60) so that they both scan across the feature to be exposed.</p> |
