摘要 |
A lithographic method of determining a sensitivity of a property of a pattern feature to change in optical aberrations of a lithographic apparatus used to provide that pattern feature. The method includes controlling a configuration of the lithographic apparatus to establish a first aberration state, forming a first image of the pattern feature with that lithographic apparatus when the lithographic apparatus is in that first aberration state, measuring a property of the image, controlling a configuration of the lithographic apparatus to establish a second, different, aberration state, forming an image of the same pattern feature with that lithographic apparatus when the lithographic apparatus is in that second aberration state, measuring a same property of the image, and using the measurements to determine the sensitivity of the property of the pattern feature to changes in the aberration state. |