摘要 |
In a method of measuring, in a lithographic manufacturing process using a lithographic projection apparatus, overlay between a resist layer (RL), in which a mask pattern (C) is to be imaged, and a substrate (W), use is made of an alignment-measuring device (AS1, AS2) forming part of the apparatus and of specific overlay marks (P10, P11) in the substrate and resist layer. These marks have periodic structures with periods (PE10, PE11) which cannot be resolved by the alignment device, but generate an interference pattern (Pb) having a period (PEb) corresponding to the period of a reference mark (M1; M2) of the alignment device.
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