摘要 |
<p>PURPOSE: A method for determining defects in a substrate and an apparatus for exposing a substrate in a lithography process are provided to determine existence of defects in the substrate, by detecting variations of fraction measured across the scan range. CONSTITUTION: An illuminator system(IL) is constituted to condition a radiation beam(B). A substrate table(WT) is constituted to keep a substrate(W). Scan range of the substrate is scanned using a sensor projecting the radiation beam on the substrate. Fraction of the intensity of the radiation reflected from different substrate regions following the scan range is measured. Variations of the fraction measured across the scan range are determined. Existence of defects in the substrate is determined from the variations.</p> |