<title>Recent developments in EUV reflectometry at the Advanced Light Source</title>

Abstract

In order to satisfy the metrology requirements of multilayer coatings for EUVL optics and masks, improvements have been made to the reflectometry beamline at the Advanced Light Source. The precision in determining multilayer peak reflectance and wavelength has been improved by reducing the measurement noise. The peak reflectance of a typical Mo/Si multilayer can now be measured with a precision of 0.08% rms (relative) and the centroid wavelength with a precision of 0.007% rms. It has now been possible to determine the contribution of scattered light to the spectral purity.Under the typical measurement conditions the scattered light accounts for about 1.3% of the incident beam. With an appropriate slit it is possible to reduce the scattered light to 0.25%. By correcting for the remaining scattered light, it is estimated that a reflectance accuracy of 0.1% (absolute) is obtained for a typical Mo/Si multilayer.

The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO)

“…Reflective X-ray Optics applied the 94-, 131-, and 335-Å flight coatings and LLNL applied the 171-, 193-, 211-Å flight coatings (Soufli et al, 2005). LLNL led the reflectance calibration and mapping of all AIA EUV flight mirrors, using the reflectometer at beam line 6.3.2 of the Advanced Light Source synchrotron at Lawrence Berkeley National Laboratory (Underwood et al, 1997;Gullikson, Mrowka, and Kaufmann, 2001).…”

EUV reflectance characterization of the 94/304 ? flight secondary AIA mirror at beamline 6.3.2 of the Advanced Light Source

“…The characteristics of the beamline and its reflectometer have been described in detail earlier 4,5 . Curved optics of up to 200 mm in diameter can be mapped in this facility.…”

Measurements of the optical constants of scandium in the 50-1300eV range

“…The transmission measurements were preformed using the Calibrations and Standards beamline 3 at the Advanced Light Source, beamline 6.3.2. This is one of the synchrotron's bending magnet beamlines, which operates in the range of 50 eV to 1,300 eV with a resolving power up to 7000.…”