| Fig.9. An example of an AFM image of a portion of two adjacent grooves of a ruled grating. The sample serial number is 1528-1-2-3. X is the axis perpendicular to the groove, Y is parallel to the grooves, and Z is the groove height. This is a planar red blazed reflection grating with a groove density of 67.556/mm. The facet shape and roughness are evident. |
| Fig.10. Contour plot of AFM data on a 3600/mm ruled grating for EUV normal incidence spectroscopy. Units are microns for the lateral scale and nm in the vertical scale bar. Rough groove edges are apparent. |
| Fig.11. The AFM image of the 2400/mm holographic master grating. The vertical scale has been exaggerated to reveal the texture of the grooves. The horizontal and vertical scales are indicated. |
| Fig.12. The histogram of the pixel heights that were derived from one 2400/mm holographic grating period of the AFM image.
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| Fig.13. The histogram of the blaze angles that were derived from one 2400/mm holographic grating period of the AFM image. |
| Fig.14. A representative scaled groove profile that was derived from the AFM image of the 2400/mm holographic grating and used in the calculation of the grating efficiency.
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Fig.15. The AFM image of 2 grooves of the 2400/mm replica grating. The image size is 1 mkm by 1 mkm. The horizontal and vertical scales are indicated.
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| Fig.16. The PSD function of the 2400/mm replica grating derived from an AFM image of size 2 mkm. |
| Fig.17. A typical groove profile derived from the AFM image of the 2400/mm replica grating. The average peak to valley groove depth is 90 Å. The blaze angles, measured from the horizontal, of the left and right facets are 3.4 deg. and 6.2 deg., respectively. |
| Fig.18. The layout of the automated efficiency checker (AEC) at Richardson Gratings (Newport Corp.) is shown. The apparatus is in a dark room and is computer operated. The grating and the scan arm can move independently to allow either monochromator mode (fixed grating deviation angle) or spectrograph mode (fixed grating incidence angle) or any other geometry (e.g. fixed wavelength, scanning incidence angle) to be measured. |