Patent ID: 7834997
Filing Date: 2010-11-16
Classification: G03F,H01J

Abstract:
1. A standard component for calibration, comprising: plural one-dimensional diffraction grating units formed on a substrate; said plural one-dimensional diffraction grating units arranged in two dimensions on a surface of said standard component; a mark associated with each one-dimensional diffraction grating unit and arranged in two dimensions and formed beside its associated one-dimensional diffraction grating unit; and plural grooves formed in the diffraction grating units and spaced from each other by a pitch spacing, the grooves having a previously found pitch dimension; wherein the marks are larger than the pitch dimension, wherein each mark is different from each other, and each mark uniquely identifies its associated diffraction grating unit within a two-dimensional arrangement, wherein said one-dimensional diffraction grating units are arranged periodically at given intervals vertically and laterally, and wherein said marks contain numerals indicating locations of said marks.