| 摘要 |
<p>In an alignment device for aligning a first object, provided with a first alignment mark (P1, P2) relative to a second object, provided with a second alignment mark (M1, M2), the radiation source (1, 1') is a laser which emits an alignment beam (b, b') having a wavelength which is of the order of at least 1000 nm and at most 1100 nm. This device has a good accuracy and reliability, also for the combination of an asymmetric alignment mark and varying thicknesses of layers on top of one of the objects (W). This device can be used to great advantage in a lithographic apparatus.</p> |
