摘要 |
<p>A method and apparatus for repetitively imaging a mask pattern (C) on a substrate (W) are described. The focusing of the projection lens system used for imaging and various other parameters of the apparatus and the projection lens system (PL), as well as illumination doses can be measured accurately and reliably, and measuring devices of the apparatus can be calibrated, by measuring an image of a new asymmetrical test mark formed in the photoresist on the substrate (W) by means of a projection beam (PB).</p> |