摘要 |
<p>A method and apparatus for repetitively imaging a mask pattern (C) on a substrate (W) are described. Various parameters of the apparatus and the projection lens system (PL) can be measured accurately and reliably and measuring devices of the apparatus can be calibrated by measuring a latent image of a mark by means of a scanning microscope (LID) forming a diffraction-limited radiation spot (Sp) on the photoresist layer on the substrate (W), in which layer the latent image is formed by means of a projection beam (PB).</p> |