CORRECTING A SUBSTRATE (PRECISION MIRROR) WITH A FIGURE CORRECTING LAYER

摘要

The figure of a substrate (10) is very precisely measured and a figured-correcting layer (14) is provided on the substrate. The thickness of the figure-correcting layer is locally measured and and compared to the first measurement. The local measurementof the figure-correcting layer is accomplished through a variety of methods, includinginterferometry and fluorescence or ultrasound measurements. Adjustments in the thickness of the figure-correcting layer are made until the top of the figure-correctinglayer matches a desired figure specification. A marker layer (12) may be used. For EUV (extreme ultra violet) optics lithography.