| 摘要 |
Two drive systems are responsible for moving a substrate beneath, for example, an illumination system or a measurement radiation beam. A first drive system drives a substrate in a X direction and a second drive system drives the substrate in a Y direction. In order to make a measurement of a feature of the substrate surface, targets are arranged in a lattice. Rather than having the lattice aligned with the X and Y directions such that only one drive system operates at a time to step between the targets, the lattice of targets is arranged at an angle with respect to the X and Y axes such that both drive systems operate simultaneously in order to move between the targets. The targets (or sub-targets within the targets) may also be arranged with respect to each other so as to save scribelane space and to create a most economical path between them.
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