3 September 2008 Surface roughness analysis of multilayer x-ray optics
Author Affiliations +
Rigaku Innovative Technologies (RIT) produces x-ray optics based on multilayer mirrors. A multilayer mirror is deposited on a wafer and mounted on a solid backing plate in an elliptical shape to focus x-rays. The wafer surface imperfections, defects from the multilayer deposition, and figure errors induced by the mounting process result in some focal spot widening for the final optics. An AFM is used in the spatial period range 0.1 - 10 microns, and a "ZYGO" interferometric microscope is used in the spatial period range 1 micron - 5 mm, to study these imperfections determining the influence of each technological step on the focal spot quality. AFM analysis shows dramatically different roughness between 1 x 1 micron and 20 x 20 micron field of view on super-polished substrates from some suppliers and only a little difference from others. A smoothing effect of a multilayer coating at spatial periods less than one micron as well as defects in multilayer coatings have been observed with power spectral density analysis. Machining marks on the surface of wafers are clearly seen at ZYGO microscope pictures. Ray-tracing simulations based on the ZYGO data show the focal spot shape changes due to the figure errors introduced at the step of a multilayer coated wafer mounting and only background scattering with no focal spot widening from defects induced at the step of multilayer deposition.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Vladimir V. Martynov, Vladimir V. Martynov, Yuriy Y. Platonov, Yuriy Y. Platonov, } "Surface roughness analysis of multilayer x-ray optics", Proc. SPIE 7077, Advances in X-Ray/EUV Optics and Components III, 707704 (3 September 2008); doi: 10.1117/12.791525; https://doi.org/10.1117/12.791525


Repair of x ray multilayer optics by use of overcoating...
Proceedings of SPIE (November 10 1994)
From x-ray telescopes to neutron focusing
Proceedings of SPIE (September 30 2011)
Repair of high-performance multilayer coatings
Proceedings of SPIE (December 31 1991)

Back to Top