Abstract

The high-spatial frequency roughness of a mirror operating at extreme ultraviolet (EUV) wavelengths is crucial for the reflective performance and is subject to very stringent specifications. To understand and predict mirror performance, precision metrology is required for measuring the surface roughness. Zerodur mirror substrates made by two different polishing vendors for a suite of EUV telescopes for solar physics were characterized by atomic force microscopy (AFM). The AFM measurements revealed features in the topography of each substrate that are associated with specific polishing techniques. Theoretical predictions of the mirror performance based on the AFM-measured high-spatial-frequency roughness are in good agreement with EUV reflectance measurements of the mirrors after multilayer coating.

© 2007 Optical Society of America

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References

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  1. For more information see the official SDO site at http://sdo.gsfc.nasa.gov/ and AIA sites at http://hea-www.harvard.edu/AIA/ and http://aia.lmsal.com/.
  2. R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).
  3. E. M. Gullikson, "Scattering from normal incidence EUV optics," Emerging Lithographic Technologies II, Y. Vladimirsky, ed., Proc. SPIE 3331, 72-80 (1998).
    [CrossRef]
  4. E. Spiller, S. Baker, E. Parra, and C. Tarrio, "Smoothing of mirror substrates by thin film deposition," in EUV, X-ray and Neutron Optics and Sources, C. A. MacDonald, K. A. Goldberg, J. R. Maldonado, H. H. Chen-Mayer and S. P. Vernon, eds., Proc. SPIE 3767, 143-153 (1999).
    [CrossRef]
  5. R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
    [CrossRef]
  6. D. G. Stearns, "Stochastic model for thin film growth and erosion," Appl. Phys. Lett. 62, 1745-1747 (1993).
    [CrossRef]
  7. A complete discussion of the EUV multilayer coatings and performance of all flight mirrors/wavelengths of the AIA instrument is beyond the scope of this manuscript and will be given in a future publication.
  8. D. L. Windt, "topo-Surface topography analysis," available at http://www.rxollc.com/idl/topo.html.
  9. J. H. Underwood and E. M. Gullikson, "High-resolution, high-flux, user friendly VLS beamline at the ALS for the 50-1300 eV energy region," J. Electr. Spectr. Rel. Phenom. 92, 265-272 (1998).
    [CrossRef]
  10. E. M. Gullikson, S. Mrowka, and B. B. Kaufmann, "Recent developments in EUV reflectometry at the Advanced Light Source," in Emerging Lithographic Technologies V, E. A. Dobisz, ed., Proc. SPIE 4343, 363-373 (2001).
    [CrossRef]
  11. F. Frost, R. Fechner, B. Ziberi, D. Flamm, and A. Schindler, "Large area smoothing of optical surfaces by low-energy ion beams," Thin Solid Films 459, 100-105 (2004).
    [CrossRef]
  12. N. Savvides, "Surface microroughness of ion-beam etched optical surfaces," J. Appl. Phys. 97, 053517 (2005).
  13. A. Duparre, J. Ferre-Borrull, S. Gliech, G. Notni, J. Steinert, and J. M. Bennett, "Surface characterization techniques for determining the root-mean-square roughness and power spectral densities of optical components," Appl. Opt. 41, 154-171 (2002).
  14. D. Flamm, F. Frost, and D. Hirsch, "Evolution of surface topography of fused silica by ion beam sputtering," Appl. Surf. Sci. 179, 95-101 (2001).
    [CrossRef]
  15. V. Holy and T. Baumbach, "Non-specular x-ray reflection from rough multilayers," Phys. Rev. B 49, 10668-10676 (1994).
    [CrossRef]

2005 (2)

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

N. Savvides, "Surface microroughness of ion-beam etched optical surfaces," J. Appl. Phys. 97, 053517 (2005).

2004 (2)

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

F. Frost, R. Fechner, B. Ziberi, D. Flamm, and A. Schindler, "Large area smoothing of optical surfaces by low-energy ion beams," Thin Solid Films 459, 100-105 (2004).
[CrossRef]

2002 (1)

2001 (2)

D. Flamm, F. Frost, and D. Hirsch, "Evolution of surface topography of fused silica by ion beam sputtering," Appl. Surf. Sci. 179, 95-101 (2001).
[CrossRef]

E. M. Gullikson, S. Mrowka, and B. B. Kaufmann, "Recent developments in EUV reflectometry at the Advanced Light Source," in Emerging Lithographic Technologies V, E. A. Dobisz, ed., Proc. SPIE 4343, 363-373 (2001).
[CrossRef]

1999 (1)

E. Spiller, S. Baker, E. Parra, and C. Tarrio, "Smoothing of mirror substrates by thin film deposition," in EUV, X-ray and Neutron Optics and Sources, C. A. MacDonald, K. A. Goldberg, J. R. Maldonado, H. H. Chen-Mayer and S. P. Vernon, eds., Proc. SPIE 3767, 143-153 (1999).
[CrossRef]

1998 (2)

J. H. Underwood and E. M. Gullikson, "High-resolution, high-flux, user friendly VLS beamline at the ALS for the 50-1300 eV energy region," J. Electr. Spectr. Rel. Phenom. 92, 265-272 (1998).
[CrossRef]

E. M. Gullikson, "Scattering from normal incidence EUV optics," Emerging Lithographic Technologies II, Y. Vladimirsky, ed., Proc. SPIE 3331, 72-80 (1998).
[CrossRef]

1994 (1)

V. Holy and T. Baumbach, "Non-specular x-ray reflection from rough multilayers," Phys. Rev. B 49, 10668-10676 (1994).
[CrossRef]

1993 (1)

D. G. Stearns, "Stochastic model for thin film growth and erosion," Appl. Phys. Lett. 62, 1745-1747 (1993).
[CrossRef]

Aquila, A. L.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

Baker, S.

E. Spiller, S. Baker, E. Parra, and C. Tarrio, "Smoothing of mirror substrates by thin film deposition," in EUV, X-ray and Neutron Optics and Sources, C. A. MacDonald, K. A. Goldberg, J. R. Maldonado, H. H. Chen-Mayer and S. P. Vernon, eds., Proc. SPIE 3767, 143-153 (1999).
[CrossRef]

Baker, S. L.

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

Baumbach, T.

V. Holy and T. Baumbach, "Non-specular x-ray reflection from rough multilayers," Phys. Rev. B 49, 10668-10676 (1994).
[CrossRef]

Bennett, J. M.

Dollar, F. J.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

Duparre, A.

Fechner, R.

F. Frost, R. Fechner, B. Ziberi, D. Flamm, and A. Schindler, "Large area smoothing of optical surfaces by low-energy ion beams," Thin Solid Films 459, 100-105 (2004).
[CrossRef]

Ferre-Borrull, J.

Flamm, D.

F. Frost, R. Fechner, B. Ziberi, D. Flamm, and A. Schindler, "Large area smoothing of optical surfaces by low-energy ion beams," Thin Solid Films 459, 100-105 (2004).
[CrossRef]

D. Flamm, F. Frost, and D. Hirsch, "Evolution of surface topography of fused silica by ion beam sputtering," Appl. Surf. Sci. 179, 95-101 (2001).
[CrossRef]

Frost, F.

F. Frost, R. Fechner, B. Ziberi, D. Flamm, and A. Schindler, "Large area smoothing of optical surfaces by low-energy ion beams," Thin Solid Films 459, 100-105 (2004).
[CrossRef]

D. Flamm, F. Frost, and D. Hirsch, "Evolution of surface topography of fused silica by ion beam sputtering," Appl. Surf. Sci. 179, 95-101 (2001).
[CrossRef]

Gliech, S.

Golub, L.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

Gullikson, E. M.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

E. M. Gullikson, S. Mrowka, and B. B. Kaufmann, "Recent developments in EUV reflectometry at the Advanced Light Source," in Emerging Lithographic Technologies V, E. A. Dobisz, ed., Proc. SPIE 4343, 363-373 (2001).
[CrossRef]

J. H. Underwood and E. M. Gullikson, "High-resolution, high-flux, user friendly VLS beamline at the ALS for the 50-1300 eV energy region," J. Electr. Spectr. Rel. Phenom. 92, 265-272 (1998).
[CrossRef]

E. M. Gullikson, "Scattering from normal incidence EUV optics," Emerging Lithographic Technologies II, Y. Vladimirsky, ed., Proc. SPIE 3331, 72-80 (1998).
[CrossRef]

Hirsch, D.

D. Flamm, F. Frost, and D. Hirsch, "Evolution of surface topography of fused silica by ion beam sputtering," Appl. Surf. Sci. 179, 95-101 (2001).
[CrossRef]

Holy, V.

V. Holy and T. Baumbach, "Non-specular x-ray reflection from rough multilayers," Phys. Rev. B 49, 10668-10676 (1994).
[CrossRef]

Johnson, M. A.

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

Kaufmann, B. B.

E. M. Gullikson, S. Mrowka, and B. B. Kaufmann, "Recent developments in EUV reflectometry at the Advanced Light Source," in Emerging Lithographic Technologies V, E. A. Dobisz, ed., Proc. SPIE 4343, 363-373 (2001).
[CrossRef]

Kjornrattanawanich, B.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

Mrowka, S.

E. M. Gullikson, S. Mrowka, and B. B. Kaufmann, "Recent developments in EUV reflectometry at the Advanced Light Source," in Emerging Lithographic Technologies V, E. A. Dobisz, ed., Proc. SPIE 4343, 363-373 (2001).
[CrossRef]

Notni, G.

Parra, E.

E. Spiller, S. Baker, E. Parra, and C. Tarrio, "Smoothing of mirror substrates by thin film deposition," in EUV, X-ray and Neutron Optics and Sources, C. A. MacDonald, K. A. Goldberg, J. R. Maldonado, H. H. Chen-Mayer and S. P. Vernon, eds., Proc. SPIE 3767, 143-153 (1999).
[CrossRef]

Ratti, S.

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

Robinson, J. C.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

Savvides, N.

N. Savvides, "Surface microroughness of ion-beam etched optical surfaces," J. Appl. Phys. 97, 053517 (2005).

Schindler, A.

F. Frost, R. Fechner, B. Ziberi, D. Flamm, and A. Schindler, "Large area smoothing of optical surfaces by low-energy ion beams," Thin Solid Films 459, 100-105 (2004).
[CrossRef]

Schmidt, M. A.

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

Seely, J. F.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

Soufli, R.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

Spiller, E.

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

E. Spiller, S. Baker, E. Parra, and C. Tarrio, "Smoothing of mirror substrates by thin film deposition," in EUV, X-ray and Neutron Optics and Sources, C. A. MacDonald, K. A. Goldberg, J. R. Maldonado, H. H. Chen-Mayer and S. P. Vernon, eds., Proc. SPIE 3767, 143-153 (1999).
[CrossRef]

Spiller, E. A.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

Stearns, D. G.

D. G. Stearns, "Stochastic model for thin film growth and erosion," Appl. Phys. Lett. 62, 1745-1747 (1993).
[CrossRef]

Steinert, J.

Tarrio, C.

E. Spiller, S. Baker, E. Parra, and C. Tarrio, "Smoothing of mirror substrates by thin film deposition," in EUV, X-ray and Neutron Optics and Sources, C. A. MacDonald, K. A. Goldberg, J. R. Maldonado, H. H. Chen-Mayer and S. P. Vernon, eds., Proc. SPIE 3767, 143-153 (1999).
[CrossRef]

Underwood, J. H.

J. H. Underwood and E. M. Gullikson, "High-resolution, high-flux, user friendly VLS beamline at the ALS for the 50-1300 eV energy region," J. Electr. Spectr. Rel. Phenom. 92, 265-272 (1998).
[CrossRef]

Windt, D. L.

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

D. L. Windt, "topo-Surface topography analysis," available at http://www.rxollc.com/idl/topo.html.

Ziberi, B.

F. Frost, R. Fechner, B. Ziberi, D. Flamm, and A. Schindler, "Large area smoothing of optical surfaces by low-energy ion beams," Thin Solid Films 459, 100-105 (2004).
[CrossRef]

Appl. Opt. (1)

Appl. Phys. Lett. (1)

D. G. Stearns, "Stochastic model for thin film growth and erosion," Appl. Phys. Lett. 62, 1745-1747 (1993).
[CrossRef]

Appl. Surf. Sci. (1)

D. Flamm, F. Frost, and D. Hirsch, "Evolution of surface topography of fused silica by ion beam sputtering," Appl. Surf. Sci. 179, 95-101 (2001).
[CrossRef]

J. Appl. Phys. (1)

N. Savvides, "Surface microroughness of ion-beam etched optical surfaces," J. Appl. Phys. 97, 053517 (2005).

J. Electr. Spectr. Rel. Phenom. (1)

J. H. Underwood and E. M. Gullikson, "High-resolution, high-flux, user friendly VLS beamline at the ALS for the 50-1300 eV energy region," J. Electr. Spectr. Rel. Phenom. 92, 265-272 (1998).
[CrossRef]

Opt. Eng. (1)

R. Soufli, E. Spiller, M. A. Schmidt, J. C. Robinson, S. L. Baker, S. Ratti, M. A. Johnson, and E. M. Gullikson, "Smoothing of diamond-turned substrates for extreme-ultraviolet illuminators," Opt. Eng. 43, 3089-3095 (2004).
[CrossRef]

Phys. Rev. B (1)

V. Holy and T. Baumbach, "Non-specular x-ray reflection from rough multilayers," Phys. Rev. B 49, 10668-10676 (1994).
[CrossRef]

Proc. SPIE (4)

R. Soufli, D. L. Windt, J. C. Robinson, E. A. Spiller, F. J. Dollar, A. L. Aquila, E. M. Gullikson, B. Kjornrattanawanich, J. F. Seely, and L. Golub, "Development and testing of EUV multilayer coatings for the atmospheric imaging assembly instrument aboard the Solar Dynamics Observatory," in Solar Physics and Space Weather Instrumentation, S. Fineschi and R. A. Viereck, eds., Proc. SPIE 5901, 59010M (2005).

E. M. Gullikson, "Scattering from normal incidence EUV optics," Emerging Lithographic Technologies II, Y. Vladimirsky, ed., Proc. SPIE 3331, 72-80 (1998).
[CrossRef]

E. Spiller, S. Baker, E. Parra, and C. Tarrio, "Smoothing of mirror substrates by thin film deposition," in EUV, X-ray and Neutron Optics and Sources, C. A. MacDonald, K. A. Goldberg, J. R. Maldonado, H. H. Chen-Mayer and S. P. Vernon, eds., Proc. SPIE 3767, 143-153 (1999).
[CrossRef]

E. M. Gullikson, S. Mrowka, and B. B. Kaufmann, "Recent developments in EUV reflectometry at the Advanced Light Source," in Emerging Lithographic Technologies V, E. A. Dobisz, ed., Proc. SPIE 4343, 363-373 (2001).
[CrossRef]

Thin Solid Films (1)

F. Frost, R. Fechner, B. Ziberi, D. Flamm, and A. Schindler, "Large area smoothing of optical surfaces by low-energy ion beams," Thin Solid Films 459, 100-105 (2004).
[CrossRef]

Other (3)

A complete discussion of the EUV multilayer coatings and performance of all flight mirrors/wavelengths of the AIA instrument is beyond the scope of this manuscript and will be given in a future publication.

D. L. Windt, "topo-Surface topography analysis," available at http://www.rxollc.com/idl/topo.html.

For more information see the official SDO site at http://sdo.gsfc.nasa.gov/ and AIA sites at http://hea-www.harvard.edu/AIA/ and http://aia.lmsal.com/.

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Figures (10)

Fig. 1
Fig. 1

(Color online) AFM measurement locations are shown for the AIA secondary substrates discussed in this manuscript. The distance of each measurement location from the center ( r = 0 ) of the substrate surface is: a = 25 mm , b = 18 mm , c = 13 mm , d = 32 mm . A 2 × 2 μm 2 and a 10 × 10 μm 2 AFM scan was performed on each location. The dash lines define the two hemi-disc areas of the substrate that were later multilayer-coated. The dimensions of the AIA secondary mirror and its clear aperture are given in Table 1. This drawing is not to scale.

Fig. 2
Fig. 2

(Color online) AFM data from an ultra-smooth silicon wafer surface with (100) orientation. (i) 2 × 2 μm 2 AFM scan. A color bar is included to indicate the range of heights on the surface. (ii) PSD derived from the AFM scan, with roughness σ = 0.04 nm rms computed from Eq. (2).

Fig. 3
Fig. 3

(Color online) AFM measurements on location b (as per the drawing of Fig. 1) on a secondary flight substrate supplied by vendor A. (i) 2 × 2 μm 2 scan (ii) 10 × 10 μm 2 scan (iii) 2-dimensional PSD derived from the 10 × 10 μm 2 AFM data in (ii). The two bright lines passing across the center in (iii) demonstrate the preferential direction of the polishing marks. The radially-averaged PSDs from the AFM data obtained on all four locations on this substrate, including location b shown here, are plotted in Fig. 4 and the corresponding rms roughness values are given in Table 2.

Fig. 4
Fig. 4

(Color online) Radially-averaged PSD curves derived from AFM measurements: 2 × 2 μm 2 frames (solid lines) and 10 × 10 μm 2 frames (dash lines) obtained on locations a, b, c, d (as per the drawing of Fig. 1) on a secondary flight substrate supplied by vendor A.

Fig. 5
Fig. 5

(Color online) EUV reflectance results measured at 87° angle from grazing incidence are shown for a Mo∕Y multilayer coating deposited on the mirror substrate from vendor A (circles) and on a Si (100) wafer substrate (squares). The reduced peak reflectance of the mirror is consistent with the high-spatial frequency roughness of each substrate.

Fig. 6
Fig. 6

(Color online) AFM measurements on location b (as per the drawing of Fig. 1) on a secondary flight substrate supplied by vendor B. (i) 2 × 2 μm 2 scan (ii) 10 × 10 μm 2 scan (iii) 2-dimensional PSD derived from the 10 × 10 μm 2 AFM data in (ii). The uniform intensity distribution around the center in (iii) demonstrates that roughness is isotropic on this substrate. The radially-averaged PSDs from the AFM data obtained on all four locations on this substrate, including location b shown here, are plotted in Fig. 7 and the corresponding rms roughness values are given in Table 3.

Fig. 7
Fig. 7

(Color online) Radially averaged PSD curves derived from AFM measurements: 2 × 2 μm 2 frames (solid lines) and 10 × 10 μm 2 frames (dash lines) obtained on locations a, b, c, d (as per the drawing of Fig. 1) on a secondary flight substrate supplied by vendor B.

Fig. 8
Fig. 8

(Color online) EUV reflectance results measured at 87° angle from grazing incidence are shown for a Mo∕Si multilayer coating deposited on the mirror substrate from vendor B (circles) and on a Si (100) wafer substrate (squares). As described in the text, the reduced peak reflectance of the mirror is consistent with the high-spatial frequency roughness of each substrate.

Fig. 9
Fig. 9

(Color online) AFM measurements on location b (as per the drawing of Fig. 1) on a secondary flight substrate supplied by vendor B. (i) 2 × 2 μm 2 and (ii) 10 × 10 μm 2 scans were obtained with the substrate as-received by the vendor. (iii) 2 × 2 μm 2 and (iv) 10 × 10 μm 2 scans were obtained after the substrate was cleaned. The contamination appearing in frames (i), (ii) is removed in frames (iii), (iv). The radially averaged PSD curves and corresponding rms roughness values from the AFM data in (i)–(iv) are given in Fig. 10.

Fig. 10
Fig. 10

(Color online) Radially-averaged PSD curves derived from the AFM measurements in Fig. 9. The rms roughness values are computed according to Eq. (2).

Tables (4)

Tables Icon

Table 1 AIA Telescope Mirror Parameters. Angles of Incidence Within the Clear Aperture (CA) are Defined from the Grazing Direction

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Table 2 Rms Roughness is Computed According to Eq. (2) for Each of the Four PSD Curves in Fig. 4, Derived from 2 × 2 μm2 AFM Data

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Table 3 Rms Roughness is Computed According to Eq. (2) for Each of the Four PSD Curves in Fig. 7, Derived from 2 × 2 μm2 AFM Data

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Table 4 High-spatial Frequency Roughness, Peak EUV Reflectance (Rpeak), and Predicted Reflectance Loss (ΔR) Due to Roughness b

Equations (2)

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z ( r ) = 1 R r 2 [ 1 + 1 ( 1 + K ) ( r / R ) 2 ] ,
σ 2 = f 1 f 2 2 π f S ( f ) d f ,

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