Abstract

We show numerically that the reflectivity of multilayer extreme-UV (EUV) mirrors tuned for the 11–14-nm spectral region, for which the two-component, Mo/Be and Mo/Si multilayer systems with constant layer thickness are commonly used, can be enhanced significantly when we incorporate additional materials within the stack. The reflectivity performance of the quarter-wavelength multilayers can be enhanced further by global optimization procedures with which the layer thicknesses are varied for optimum performance. By incorporating additional materials of differing complex refractive indices—e.g., Rh, Ru, Sr, Pd, and RbCl—in various regions of the stack, we observed peak reflectivity enhancements of as much as ∼5% for a single reflector compared with standard unoptimized stacks. We show that, in an EUV optical system with nine near-normal-incidence mirror surfaces, the optical throughput may be increased by a factor as great as 2. We also show that protective capping layers, in addition to protecting the mirrors from environmental attack, may serve to improve the reflectivity characteristics.

© 2000 Optical Society of America

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References

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  1. R. H. Stulen, D. W. Sweeney, “Extreme ultraviolet lithography,” IEEE J. Quantum Electron. 35, 694–699 (1999).
    [CrossRef]
  2. C. W. Gwyn, R. Stulen, D. Sweeney, D. Attwood, “Extreme ultraviolet lithography,” J. Vac. Sci. Technol. B 16, 3142–3149 (1998).
    [CrossRef]
  3. E. Spiller, Soft X-Ray Optics (SPIE Optical Engineering Press, Bellingham, Wash., 1994), Chap. 8.
    [CrossRef]
  4. K. M. Skulina, C. S. Alford, R. M. Bionta, D. M. Makowiecki, E. M. Gullikson, R. Soufli, J. B. Kortright, J. H. Underwood, “Molybdenum/beryllium multilayer mirrors for normal incidence in the extreme ultraviolet,” Appl. Opt. 34, 3727–3730 (1995).
    [CrossRef] [PubMed]
  5. D. G. Stearns, R. S. Rosen, S. P. Vernon, “Multilayer mirror technology for soft-x-ray projection lithography,” Appl. Opt. 32, 6952–6960 (1993).
    [CrossRef] [PubMed]
  6. A. V. Vinogradov, B. Ya. Zeldovich, “X-ray and far UV multilayer mirrors: principles and possibilities,” Appl. Opt. 16, 89–93 (1977).
    [CrossRef] [PubMed]
  7. C. K. Carniglia, J. H. Apfel, “Maximum reflectance of multilayer dielectric mirrors in the presence of slight absorption,” J. Opt. Soc. Am. 70, 523–534 (1980).
    [CrossRef]
  8. J. H. Underwood, T. W. Barbee, “Layered synthetic microstructures as Bragg diffractors for x-rays and extreme ultraviolet: theory and predicted performance,” Appl. Opt. 20, 3027–3034 (1981).
    [CrossRef] [PubMed]
  9. B. Vidal, P. Vincent, “Metallic multilayers for x-rays using classical thin-film theory,” Appl. Opt. 23, 1794–1801 (1984).
    [CrossRef]
  10. J. F. Meekins, R. G. Cruddace, H. Gursky, “Optimization of layered synthetic microstructures for narrowband reflectivity at soft x-ray and EUV wavelengths,” Appl. Opt. 25, 2757–2763 (1986).
    [CrossRef] [PubMed]
  11. M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, Oxford, 1980), pp. 55–70.
  12. D. W. Berreman, “Optics in stratified and anisotropic media: 4 × 4-matrix formulation,” J. Opt. Soc. Am. 62, 502–510 (1972).
    [CrossRef]
  13. A. V. Tikhonravov, M. K. Trubetskov, G. W. DeBell, “Application of the needle optimization technique to the design of optical coatings,” Appl. Opt. 35, 5493–5508 (1996).
    [CrossRef] [PubMed]
  14. A. V. Tikhonravov, “Some theoretical aspects of thin-film optics and their applications,” Appl. Opt. 32, 5417–5426 (1993).
    [CrossRef] [PubMed]
  15. P. G. Verly, A. V. Tikhonravov, M. K. Trubetskov, “Efficient refinement algorithm for the synthesis of inhomogeneous optical coatings,” Appl. Opt. 36, 1487–1495 (1997).
    [CrossRef] [PubMed]
  16. A. V. Tikhonravov, M. K. Trubetskov, B. T. Sullivan, J. A. Dobrowolski, “Influence of small inhomogeneities on the spectral characteristics of single thin films,” Appl. Opt. 36, 7188–7198 (1997).
    [CrossRef]
  17. J. A. Dobrowolski, R. A. Kemp, “Refinement of optical multilayer systems with different optimization procedures,” Appl. Opt. 29, 2876–2893 (1990).
    [CrossRef] [PubMed]
  18. B. T. Sullivan, J. A. Dobrowolski, “Implementation of a numerical needle method for thin-film design,” Appl. Opt. 35, 5484–5492 (1996).
    [CrossRef] [PubMed]
  19. B. L. Henke, E. M. Gullikson, J. C. Davis, “X-ray interactions: photoabsortion, scattering, transmission and reflection at E = 50–30,000 eV, Z = 1–92,” At. Data Nucl. Data Tables 54, 181–342 (1993); also see http://www-cxro.lbl.gov/optical_constants .
    [CrossRef]
  20. M. Yamamoto, M. Yanagihara, A. Arai, J. Cao, N. T. Mizuide, T. Namioka, “Multilayer mirrors for use as wavelength-selective filter around 100 eV,” Rev. Sci. Instrum. 60, 2010–2013 (1989).
    [CrossRef]
  21. M. Yanagihara, T. Maehara, H. Nomura, M. Yamamoto, T. Namioka, “Performance of a wideband multilayer polarizer for soft x-rays,” Rev. Sci. Instrum. 63, 1516–1518 (1992).
    [CrossRef]
  22. D.-E. Kim, S.-M. Lee, I. Jeon, “Transmission characteristics of multilayer structure in the soft x-ray spectral region and its application to the design of quarter-wave plates at 13 and 4.4 nm,” J. Vac. Sci. Technol. A 17, 398–402 (1999).
    [CrossRef]
  23. D. L. Windt, R. Hull, W. K. Waskiewicz, “Interface imperfections in metal/Si multilayers,” J. Appl. Phys. 71, 2675–2678 (1992).
    [CrossRef]
  24. M. Yanagihara, T. Maehara, S. Gunadi, M. Asano, T. Namioka, “In situ performance tests of soft-x-ray multilayer mirrors exposed to synchrotron radiation from a bending magnet,” Appl. Opt. 31, 972–976 (1992).
    [CrossRef] [PubMed]
  25. E. Spiller, A. E. Rosenbluth, “Determination of thickness errors and boundary roughness from the measured performance of a multilayer coating,” Opt. Eng. 25, 954–963 (1986).
    [CrossRef]
  26. E. Spiller, “Enhancement of the reflectivity of multilayer x-ray mirrors by ion polishing,” Opt. Eng. 29, 609–613 (1990).
    [CrossRef]

1999 (2)

R. H. Stulen, D. W. Sweeney, “Extreme ultraviolet lithography,” IEEE J. Quantum Electron. 35, 694–699 (1999).
[CrossRef]

D.-E. Kim, S.-M. Lee, I. Jeon, “Transmission characteristics of multilayer structure in the soft x-ray spectral region and its application to the design of quarter-wave plates at 13 and 4.4 nm,” J. Vac. Sci. Technol. A 17, 398–402 (1999).
[CrossRef]

1998 (1)

C. W. Gwyn, R. Stulen, D. Sweeney, D. Attwood, “Extreme ultraviolet lithography,” J. Vac. Sci. Technol. B 16, 3142–3149 (1998).
[CrossRef]

1997 (2)

1996 (2)

1995 (1)

1993 (3)

D. G. Stearns, R. S. Rosen, S. P. Vernon, “Multilayer mirror technology for soft-x-ray projection lithography,” Appl. Opt. 32, 6952–6960 (1993).
[CrossRef] [PubMed]

B. L. Henke, E. M. Gullikson, J. C. Davis, “X-ray interactions: photoabsortion, scattering, transmission and reflection at E = 50–30,000 eV, Z = 1–92,” At. Data Nucl. Data Tables 54, 181–342 (1993); also see http://www-cxro.lbl.gov/optical_constants .
[CrossRef]

A. V. Tikhonravov, “Some theoretical aspects of thin-film optics and their applications,” Appl. Opt. 32, 5417–5426 (1993).
[CrossRef] [PubMed]

1992 (3)

M. Yanagihara, T. Maehara, H. Nomura, M. Yamamoto, T. Namioka, “Performance of a wideband multilayer polarizer for soft x-rays,” Rev. Sci. Instrum. 63, 1516–1518 (1992).
[CrossRef]

D. L. Windt, R. Hull, W. K. Waskiewicz, “Interface imperfections in metal/Si multilayers,” J. Appl. Phys. 71, 2675–2678 (1992).
[CrossRef]

M. Yanagihara, T. Maehara, S. Gunadi, M. Asano, T. Namioka, “In situ performance tests of soft-x-ray multilayer mirrors exposed to synchrotron radiation from a bending magnet,” Appl. Opt. 31, 972–976 (1992).
[CrossRef] [PubMed]

1990 (2)

E. Spiller, “Enhancement of the reflectivity of multilayer x-ray mirrors by ion polishing,” Opt. Eng. 29, 609–613 (1990).
[CrossRef]

J. A. Dobrowolski, R. A. Kemp, “Refinement of optical multilayer systems with different optimization procedures,” Appl. Opt. 29, 2876–2893 (1990).
[CrossRef] [PubMed]

1989 (1)

M. Yamamoto, M. Yanagihara, A. Arai, J. Cao, N. T. Mizuide, T. Namioka, “Multilayer mirrors for use as wavelength-selective filter around 100 eV,” Rev. Sci. Instrum. 60, 2010–2013 (1989).
[CrossRef]

1986 (2)

J. F. Meekins, R. G. Cruddace, H. Gursky, “Optimization of layered synthetic microstructures for narrowband reflectivity at soft x-ray and EUV wavelengths,” Appl. Opt. 25, 2757–2763 (1986).
[CrossRef] [PubMed]

E. Spiller, A. E. Rosenbluth, “Determination of thickness errors and boundary roughness from the measured performance of a multilayer coating,” Opt. Eng. 25, 954–963 (1986).
[CrossRef]

1984 (1)

1981 (1)

1980 (1)

1977 (1)

1972 (1)

Alford, C. S.

Apfel, J. H.

Arai, A.

M. Yamamoto, M. Yanagihara, A. Arai, J. Cao, N. T. Mizuide, T. Namioka, “Multilayer mirrors for use as wavelength-selective filter around 100 eV,” Rev. Sci. Instrum. 60, 2010–2013 (1989).
[CrossRef]

Asano, M.

Attwood, D.

C. W. Gwyn, R. Stulen, D. Sweeney, D. Attwood, “Extreme ultraviolet lithography,” J. Vac. Sci. Technol. B 16, 3142–3149 (1998).
[CrossRef]

Barbee, T. W.

Berreman, D. W.

Bionta, R. M.

Born, M.

M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, Oxford, 1980), pp. 55–70.

Cao, J.

M. Yamamoto, M. Yanagihara, A. Arai, J. Cao, N. T. Mizuide, T. Namioka, “Multilayer mirrors for use as wavelength-selective filter around 100 eV,” Rev. Sci. Instrum. 60, 2010–2013 (1989).
[CrossRef]

Carniglia, C. K.

Cruddace, R. G.

Davis, J. C.

B. L. Henke, E. M. Gullikson, J. C. Davis, “X-ray interactions: photoabsortion, scattering, transmission and reflection at E = 50–30,000 eV, Z = 1–92,” At. Data Nucl. Data Tables 54, 181–342 (1993); also see http://www-cxro.lbl.gov/optical_constants .
[CrossRef]

DeBell, G. W.

Dobrowolski, J. A.

Gullikson, E. M.

K. M. Skulina, C. S. Alford, R. M. Bionta, D. M. Makowiecki, E. M. Gullikson, R. Soufli, J. B. Kortright, J. H. Underwood, “Molybdenum/beryllium multilayer mirrors for normal incidence in the extreme ultraviolet,” Appl. Opt. 34, 3727–3730 (1995).
[CrossRef] [PubMed]

B. L. Henke, E. M. Gullikson, J. C. Davis, “X-ray interactions: photoabsortion, scattering, transmission and reflection at E = 50–30,000 eV, Z = 1–92,” At. Data Nucl. Data Tables 54, 181–342 (1993); also see http://www-cxro.lbl.gov/optical_constants .
[CrossRef]

Gunadi, S.

Gursky, H.

Gwyn, C. W.

C. W. Gwyn, R. Stulen, D. Sweeney, D. Attwood, “Extreme ultraviolet lithography,” J. Vac. Sci. Technol. B 16, 3142–3149 (1998).
[CrossRef]

Henke, B. L.

B. L. Henke, E. M. Gullikson, J. C. Davis, “X-ray interactions: photoabsortion, scattering, transmission and reflection at E = 50–30,000 eV, Z = 1–92,” At. Data Nucl. Data Tables 54, 181–342 (1993); also see http://www-cxro.lbl.gov/optical_constants .
[CrossRef]

Hull, R.

D. L. Windt, R. Hull, W. K. Waskiewicz, “Interface imperfections in metal/Si multilayers,” J. Appl. Phys. 71, 2675–2678 (1992).
[CrossRef]

Jeon, I.

D.-E. Kim, S.-M. Lee, I. Jeon, “Transmission characteristics of multilayer structure in the soft x-ray spectral region and its application to the design of quarter-wave plates at 13 and 4.4 nm,” J. Vac. Sci. Technol. A 17, 398–402 (1999).
[CrossRef]

Kemp, R. A.

Kim, D.-E.

D.-E. Kim, S.-M. Lee, I. Jeon, “Transmission characteristics of multilayer structure in the soft x-ray spectral region and its application to the design of quarter-wave plates at 13 and 4.4 nm,” J. Vac. Sci. Technol. A 17, 398–402 (1999).
[CrossRef]

Kortright, J. B.

Lee, S.-M.

D.-E. Kim, S.-M. Lee, I. Jeon, “Transmission characteristics of multilayer structure in the soft x-ray spectral region and its application to the design of quarter-wave plates at 13 and 4.4 nm,” J. Vac. Sci. Technol. A 17, 398–402 (1999).
[CrossRef]

Maehara, T.

M. Yanagihara, T. Maehara, H. Nomura, M. Yamamoto, T. Namioka, “Performance of a wideband multilayer polarizer for soft x-rays,” Rev. Sci. Instrum. 63, 1516–1518 (1992).
[CrossRef]

M. Yanagihara, T. Maehara, S. Gunadi, M. Asano, T. Namioka, “In situ performance tests of soft-x-ray multilayer mirrors exposed to synchrotron radiation from a bending magnet,” Appl. Opt. 31, 972–976 (1992).
[CrossRef] [PubMed]

Makowiecki, D. M.

Meekins, J. F.

Mizuide, N. T.

M. Yamamoto, M. Yanagihara, A. Arai, J. Cao, N. T. Mizuide, T. Namioka, “Multilayer mirrors for use as wavelength-selective filter around 100 eV,” Rev. Sci. Instrum. 60, 2010–2013 (1989).
[CrossRef]

Namioka, T.

M. Yanagihara, T. Maehara, H. Nomura, M. Yamamoto, T. Namioka, “Performance of a wideband multilayer polarizer for soft x-rays,” Rev. Sci. Instrum. 63, 1516–1518 (1992).
[CrossRef]

M. Yanagihara, T. Maehara, S. Gunadi, M. Asano, T. Namioka, “In situ performance tests of soft-x-ray multilayer mirrors exposed to synchrotron radiation from a bending magnet,” Appl. Opt. 31, 972–976 (1992).
[CrossRef] [PubMed]

M. Yamamoto, M. Yanagihara, A. Arai, J. Cao, N. T. Mizuide, T. Namioka, “Multilayer mirrors for use as wavelength-selective filter around 100 eV,” Rev. Sci. Instrum. 60, 2010–2013 (1989).
[CrossRef]

Nomura, H.

M. Yanagihara, T. Maehara, H. Nomura, M. Yamamoto, T. Namioka, “Performance of a wideband multilayer polarizer for soft x-rays,” Rev. Sci. Instrum. 63, 1516–1518 (1992).
[CrossRef]

Rosen, R. S.

Rosenbluth, A. E.

E. Spiller, A. E. Rosenbluth, “Determination of thickness errors and boundary roughness from the measured performance of a multilayer coating,” Opt. Eng. 25, 954–963 (1986).
[CrossRef]

Skulina, K. M.

Soufli, R.

Spiller, E.

E. Spiller, “Enhancement of the reflectivity of multilayer x-ray mirrors by ion polishing,” Opt. Eng. 29, 609–613 (1990).
[CrossRef]

E. Spiller, A. E. Rosenbluth, “Determination of thickness errors and boundary roughness from the measured performance of a multilayer coating,” Opt. Eng. 25, 954–963 (1986).
[CrossRef]

E. Spiller, Soft X-Ray Optics (SPIE Optical Engineering Press, Bellingham, Wash., 1994), Chap. 8.
[CrossRef]

Stearns, D. G.

Stulen, R.

C. W. Gwyn, R. Stulen, D. Sweeney, D. Attwood, “Extreme ultraviolet lithography,” J. Vac. Sci. Technol. B 16, 3142–3149 (1998).
[CrossRef]

Stulen, R. H.

R. H. Stulen, D. W. Sweeney, “Extreme ultraviolet lithography,” IEEE J. Quantum Electron. 35, 694–699 (1999).
[CrossRef]

Sullivan, B. T.

Sweeney, D.

C. W. Gwyn, R. Stulen, D. Sweeney, D. Attwood, “Extreme ultraviolet lithography,” J. Vac. Sci. Technol. B 16, 3142–3149 (1998).
[CrossRef]

Sweeney, D. W.

R. H. Stulen, D. W. Sweeney, “Extreme ultraviolet lithography,” IEEE J. Quantum Electron. 35, 694–699 (1999).
[CrossRef]

Tikhonravov, A. V.

Trubetskov, M. K.

Underwood, J. H.

Verly, P. G.

Vernon, S. P.

Vidal, B.

Vincent, P.

Vinogradov, A. V.

Waskiewicz, W. K.

D. L. Windt, R. Hull, W. K. Waskiewicz, “Interface imperfections in metal/Si multilayers,” J. Appl. Phys. 71, 2675–2678 (1992).
[CrossRef]

Windt, D. L.

D. L. Windt, R. Hull, W. K. Waskiewicz, “Interface imperfections in metal/Si multilayers,” J. Appl. Phys. 71, 2675–2678 (1992).
[CrossRef]

Wolf, E.

M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, Oxford, 1980), pp. 55–70.

Yamamoto, M.

M. Yanagihara, T. Maehara, H. Nomura, M. Yamamoto, T. Namioka, “Performance of a wideband multilayer polarizer for soft x-rays,” Rev. Sci. Instrum. 63, 1516–1518 (1992).
[CrossRef]

M. Yamamoto, M. Yanagihara, A. Arai, J. Cao, N. T. Mizuide, T. Namioka, “Multilayer mirrors for use as wavelength-selective filter around 100 eV,” Rev. Sci. Instrum. 60, 2010–2013 (1989).
[CrossRef]

Yanagihara, M.

M. Yanagihara, T. Maehara, S. Gunadi, M. Asano, T. Namioka, “In situ performance tests of soft-x-ray multilayer mirrors exposed to synchrotron radiation from a bending magnet,” Appl. Opt. 31, 972–976 (1992).
[CrossRef] [PubMed]

M. Yanagihara, T. Maehara, H. Nomura, M. Yamamoto, T. Namioka, “Performance of a wideband multilayer polarizer for soft x-rays,” Rev. Sci. Instrum. 63, 1516–1518 (1992).
[CrossRef]

M. Yamamoto, M. Yanagihara, A. Arai, J. Cao, N. T. Mizuide, T. Namioka, “Multilayer mirrors for use as wavelength-selective filter around 100 eV,” Rev. Sci. Instrum. 60, 2010–2013 (1989).
[CrossRef]

Zeldovich, B. Ya.

Appl. Opt. (13)

K. M. Skulina, C. S. Alford, R. M. Bionta, D. M. Makowiecki, E. M. Gullikson, R. Soufli, J. B. Kortright, J. H. Underwood, “Molybdenum/beryllium multilayer mirrors for normal incidence in the extreme ultraviolet,” Appl. Opt. 34, 3727–3730 (1995).
[CrossRef] [PubMed]

D. G. Stearns, R. S. Rosen, S. P. Vernon, “Multilayer mirror technology for soft-x-ray projection lithography,” Appl. Opt. 32, 6952–6960 (1993).
[CrossRef] [PubMed]

A. V. Vinogradov, B. Ya. Zeldovich, “X-ray and far UV multilayer mirrors: principles and possibilities,” Appl. Opt. 16, 89–93 (1977).
[CrossRef] [PubMed]

J. H. Underwood, T. W. Barbee, “Layered synthetic microstructures as Bragg diffractors for x-rays and extreme ultraviolet: theory and predicted performance,” Appl. Opt. 20, 3027–3034 (1981).
[CrossRef] [PubMed]

B. Vidal, P. Vincent, “Metallic multilayers for x-rays using classical thin-film theory,” Appl. Opt. 23, 1794–1801 (1984).
[CrossRef]

J. F. Meekins, R. G. Cruddace, H. Gursky, “Optimization of layered synthetic microstructures for narrowband reflectivity at soft x-ray and EUV wavelengths,” Appl. Opt. 25, 2757–2763 (1986).
[CrossRef] [PubMed]

A. V. Tikhonravov, M. K. Trubetskov, G. W. DeBell, “Application of the needle optimization technique to the design of optical coatings,” Appl. Opt. 35, 5493–5508 (1996).
[CrossRef] [PubMed]

A. V. Tikhonravov, “Some theoretical aspects of thin-film optics and their applications,” Appl. Opt. 32, 5417–5426 (1993).
[CrossRef] [PubMed]

P. G. Verly, A. V. Tikhonravov, M. K. Trubetskov, “Efficient refinement algorithm for the synthesis of inhomogeneous optical coatings,” Appl. Opt. 36, 1487–1495 (1997).
[CrossRef] [PubMed]

A. V. Tikhonravov, M. K. Trubetskov, B. T. Sullivan, J. A. Dobrowolski, “Influence of small inhomogeneities on the spectral characteristics of single thin films,” Appl. Opt. 36, 7188–7198 (1997).
[CrossRef]

J. A. Dobrowolski, R. A. Kemp, “Refinement of optical multilayer systems with different optimization procedures,” Appl. Opt. 29, 2876–2893 (1990).
[CrossRef] [PubMed]

B. T. Sullivan, J. A. Dobrowolski, “Implementation of a numerical needle method for thin-film design,” Appl. Opt. 35, 5484–5492 (1996).
[CrossRef] [PubMed]

M. Yanagihara, T. Maehara, S. Gunadi, M. Asano, T. Namioka, “In situ performance tests of soft-x-ray multilayer mirrors exposed to synchrotron radiation from a bending magnet,” Appl. Opt. 31, 972–976 (1992).
[CrossRef] [PubMed]

At. Data Nucl. Data Tables (1)

B. L. Henke, E. M. Gullikson, J. C. Davis, “X-ray interactions: photoabsortion, scattering, transmission and reflection at E = 50–30,000 eV, Z = 1–92,” At. Data Nucl. Data Tables 54, 181–342 (1993); also see http://www-cxro.lbl.gov/optical_constants .
[CrossRef]

IEEE J. Quantum Electron. (1)

R. H. Stulen, D. W. Sweeney, “Extreme ultraviolet lithography,” IEEE J. Quantum Electron. 35, 694–699 (1999).
[CrossRef]

J. Appl. Phys. (1)

D. L. Windt, R. Hull, W. K. Waskiewicz, “Interface imperfections in metal/Si multilayers,” J. Appl. Phys. 71, 2675–2678 (1992).
[CrossRef]

J. Opt. Soc. Am. (2)

J. Vac. Sci. Technol. A (1)

D.-E. Kim, S.-M. Lee, I. Jeon, “Transmission characteristics of multilayer structure in the soft x-ray spectral region and its application to the design of quarter-wave plates at 13 and 4.4 nm,” J. Vac. Sci. Technol. A 17, 398–402 (1999).
[CrossRef]

J. Vac. Sci. Technol. B (1)

C. W. Gwyn, R. Stulen, D. Sweeney, D. Attwood, “Extreme ultraviolet lithography,” J. Vac. Sci. Technol. B 16, 3142–3149 (1998).
[CrossRef]

Opt. Eng. (2)

E. Spiller, A. E. Rosenbluth, “Determination of thickness errors and boundary roughness from the measured performance of a multilayer coating,” Opt. Eng. 25, 954–963 (1986).
[CrossRef]

E. Spiller, “Enhancement of the reflectivity of multilayer x-ray mirrors by ion polishing,” Opt. Eng. 29, 609–613 (1990).
[CrossRef]

Rev. Sci. Instrum. (2)

M. Yamamoto, M. Yanagihara, A. Arai, J. Cao, N. T. Mizuide, T. Namioka, “Multilayer mirrors for use as wavelength-selective filter around 100 eV,” Rev. Sci. Instrum. 60, 2010–2013 (1989).
[CrossRef]

M. Yanagihara, T. Maehara, H. Nomura, M. Yamamoto, T. Namioka, “Performance of a wideband multilayer polarizer for soft x-rays,” Rev. Sci. Instrum. 63, 1516–1518 (1992).
[CrossRef]

Other (2)

M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, Oxford, 1980), pp. 55–70.

E. Spiller, Soft X-Ray Optics (SPIE Optical Engineering Press, Bellingham, Wash., 1994), Chap. 8.
[CrossRef]

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Figures (10)

Fig. 1
Fig. 1

Layer thickness profiles in 50-period optimized Mo/Si stack with 1.5-nm Ru capping layer. Layer 0 corresponds to the substrate surface.

Fig. 2
Fig. 2

Plots of R 9 versus wavelength in 13.4-nm region. A, Standard Mo/Si stack; B, optimized Mo/Si; C, Ru-Mo/Si needle optimized; D, Ru-Mo/Sr-Si needle optimized; E, Mo/Rb optimized. (Rint9 is obtained from the area under the bands).

Fig. 3
Fig. 3

Layer profiles in 148-layer (50-Si-layer) Ru-Mo/Si stack with 1.5-nm Ru capping layer. The predominance of Ru over Mo near the substrate (Layer 0) is clearly observed.

Fig. 4
Fig. 4

Layer thickness profiles of Ru-Mo/Sr-Si multilayer stack (50 Si layers) with Ru capping layer.

Fig. 5
Fig. 5

Layer thickness profiles of optimized Pd-Ru-Mo/Si (50 Si layers).

Fig. 6
Fig. 6

Layer thickness profiles of Ru/Sr-Be multilayer stack with 80 Be layers and capped with 1.5-nm Ru layer. The substrate surface is at layer 0.

Fig. 7
Fig. 7

Plots of R 9 versus wavelength in 11.3-nm region. A, Standard Mo/Be stack; B, Mo/Be Ru-capped, optimized; C, Rh-Mo/Si optimized; D, Ru/Be optimized; E, Rh/Be needle optimized; F, Ru/Sr-Be needle optimized. (Rint9 is obtained from the area under the bands).

Fig. 8
Fig. 8

Layer thickness profiles of optimized Rh-Mo/Be multilayer showing clearly that Rh is preferred near the substrate, because its n is lower than that of Mo despite a higher k.

Fig. 9
Fig. 9

comparison of the R 7 response as a function of incidence angle of the TE and the TM polarizations of the standard and the optimized Mo/Si stacks tuned for 7°.

Fig. 10
Fig. 10

A, Pd-Ru-Mo/Si stack optimized for single reflectivity target at 13.4 nm; B, same stack optimized for multiple reflectivity targets at 13.1, 13.25, 13.4, 13.5, and 13.57 nm, showing higher FWHM and Rint9.

Tables (3)

Tables Icon

Table 1 Values of n and k at 11.3 and 13.4 nm

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Table 2 Si- and Rb-Based 50-Period Multilayer Stacks Tuned for 13.4 nm Indicating the Peak Reflectivity (R) and the Relative Values of R9, Peak and Integrated

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Table 3 Be-Based 80-Period Multilayer Stacks Tuned for 11.3 nm Indicating the Peak Reflectivity (R) and the Relative Values of R9, Peak and Integrated

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