Abstract

Absorbance-modulated lithography is a relatively new optical patterning method where a thin layer of photochromic molecules is placed between the far-field optics and photoresist. These molecules can be made transparent or opaque by illuminating with wavelengths λ1 or λ2, respectively. By simultaneously illuminating this layer with patterns of both wavelengths it is possible to create an absorption mask capable of subwavelength resolution. This resolution comes at the price of limited contrast and depth-of-focus resulting in poor process latitude. Here it is shown that by using TM polarization for λ1 and integrating a plasmonic reflector process latitude is increased by up to 66%.

© 2011 OSA

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. S. Okazaki, “Resolution limits of optical lithography,” J. Vac. Sci. Technol. B 9(6), 2829–2833 (1991).
    [CrossRef]
  2. E. Muzio, “Optical lithography cost of ownership (COO) – final report for LITG501,” SEMATECH, (2000) http://www.sematech.org/docubase/document/4014atr.pdf .
  3. T. Ito, T. Yamada, Y. Inao, T. Yamaguchi, N. Mizutani, and R. Kuroda, “Fabrication of half-pitch 32 nm resist pattern using near-field lithography with a-Si mask,” Appl. Phys. Lett. 89(3), 033113 (2006).
    [CrossRef]
  4. R. Menon and H. I. Smith, “Absorbance-modulation optical lithography,” J. Opt. Soc. Am. A 23(9), 2290–2294 (2006).
    [CrossRef] [PubMed]
  5. T. L. Andrew, H. Y. Tsai, and R. Menon, “Confining light to deep subwavelength dimensions to enable optical nanopatterning,” Science 324(5929), 917–921 (2009).
    [CrossRef] [PubMed]
  6. R. Menon, H. Y. Tsai, and S. W. Thomas, “Far-field generation of localized light fields using absorbance modulation,” Phys. Rev. Lett. 98(4), 043905 (2007).
    [CrossRef] [PubMed]
  7. J. Foulkes and R. J. Blaikie, “Influence of polarization on absorbance modulated subwavelength grating structures,” J. Vac. Sci. Technol. B 27(6), 2941–2946 (2009).
    [CrossRef]
  8. M. D. Arnold and R. J. Blaikie, “Subwavelength optical imaging of evanescent fields using reflections from plasmonic slabs,” Opt. Express 15(18), 11542–11552 (2007).
    [CrossRef] [PubMed]
  9. COMSOL Inc, 744 Cowper Steet, Palo Alto, CA 94301, www.comsol.com .
  10. S. M. Rytov, “Electromagnetic properties of a finely stratified medium,” Sov. Phys. JETP 2, 466–475 (1956).
  11. H. S. Ho, A. Natansohn, C. Barrett, and P. Rochon, “Azo polymers for reversible optical storage. 8. The effect of polarity of the azobenzene groups,” Can. J. Chem. 72(11), 1773–1778 (1995).
    [CrossRef]
  12. C. Barrett, A. Natansohn, and P. Rochon, “Cis-trans thermal isomerization rates of bound and doped azobenzenes in a series of polymers,” Chem. Mater. 7(5), 899–903 (1995).
    [CrossRef]
  13. N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
    [CrossRef]
  14. C. J. Barrett, A. L. Natansohn, and P. L. Rochon, “Mechanism of optically inscribed high-efficiency diffraction gratings in azo polymer films,” J. Phys. Chem. 100(21), 8836–8842 (1996).
    [CrossRef]

2009 (2)

T. L. Andrew, H. Y. Tsai, and R. Menon, “Confining light to deep subwavelength dimensions to enable optical nanopatterning,” Science 324(5929), 917–921 (2009).
[CrossRef] [PubMed]

J. Foulkes and R. J. Blaikie, “Influence of polarization on absorbance modulated subwavelength grating structures,” J. Vac. Sci. Technol. B 27(6), 2941–2946 (2009).
[CrossRef]

2007 (2)

R. Menon, H. Y. Tsai, and S. W. Thomas, “Far-field generation of localized light fields using absorbance modulation,” Phys. Rev. Lett. 98(4), 043905 (2007).
[CrossRef] [PubMed]

M. D. Arnold and R. J. Blaikie, “Subwavelength optical imaging of evanescent fields using reflections from plasmonic slabs,” Opt. Express 15(18), 11542–11552 (2007).
[CrossRef] [PubMed]

2006 (2)

T. Ito, T. Yamada, Y. Inao, T. Yamaguchi, N. Mizutani, and R. Kuroda, “Fabrication of half-pitch 32 nm resist pattern using near-field lithography with a-Si mask,” Appl. Phys. Lett. 89(3), 033113 (2006).
[CrossRef]

R. Menon and H. I. Smith, “Absorbance-modulation optical lithography,” J. Opt. Soc. Am. A 23(9), 2290–2294 (2006).
[CrossRef] [PubMed]

1999 (1)

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

1996 (1)

C. J. Barrett, A. L. Natansohn, and P. L. Rochon, “Mechanism of optically inscribed high-efficiency diffraction gratings in azo polymer films,” J. Phys. Chem. 100(21), 8836–8842 (1996).
[CrossRef]

1995 (2)

H. S. Ho, A. Natansohn, C. Barrett, and P. Rochon, “Azo polymers for reversible optical storage. 8. The effect of polarity of the azobenzene groups,” Can. J. Chem. 72(11), 1773–1778 (1995).
[CrossRef]

C. Barrett, A. Natansohn, and P. Rochon, “Cis-trans thermal isomerization rates of bound and doped azobenzenes in a series of polymers,” Chem. Mater. 7(5), 899–903 (1995).
[CrossRef]

1991 (1)

S. Okazaki, “Resolution limits of optical lithography,” J. Vac. Sci. Technol. B 9(6), 2829–2833 (1991).
[CrossRef]

1956 (1)

S. M. Rytov, “Electromagnetic properties of a finely stratified medium,” Sov. Phys. JETP 2, 466–475 (1956).

Andrew, T. L.

T. L. Andrew, H. Y. Tsai, and R. Menon, “Confining light to deep subwavelength dimensions to enable optical nanopatterning,” Science 324(5929), 917–921 (2009).
[CrossRef] [PubMed]

Arnold, M. D.

Barrett, C.

H. S. Ho, A. Natansohn, C. Barrett, and P. Rochon, “Azo polymers for reversible optical storage. 8. The effect of polarity of the azobenzene groups,” Can. J. Chem. 72(11), 1773–1778 (1995).
[CrossRef]

C. Barrett, A. Natansohn, and P. Rochon, “Cis-trans thermal isomerization rates of bound and doped azobenzenes in a series of polymers,” Chem. Mater. 7(5), 899–903 (1995).
[CrossRef]

Barrett, C. J.

C. J. Barrett, A. L. Natansohn, and P. L. Rochon, “Mechanism of optically inscribed high-efficiency diffraction gratings in azo polymer films,” J. Phys. Chem. 100(21), 8836–8842 (1996).
[CrossRef]

Bian, S.

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

Blaikie, R. J.

J. Foulkes and R. J. Blaikie, “Influence of polarization on absorbance modulated subwavelength grating structures,” J. Vac. Sci. Technol. B 27(6), 2941–2946 (2009).
[CrossRef]

M. D. Arnold and R. J. Blaikie, “Subwavelength optical imaging of evanescent fields using reflections from plasmonic slabs,” Opt. Express 15(18), 11542–11552 (2007).
[CrossRef] [PubMed]

Foulkes, J.

J. Foulkes and R. J. Blaikie, “Influence of polarization on absorbance modulated subwavelength grating structures,” J. Vac. Sci. Technol. B 27(6), 2941–2946 (2009).
[CrossRef]

Ho, H. S.

H. S. Ho, A. Natansohn, C. Barrett, and P. Rochon, “Azo polymers for reversible optical storage. 8. The effect of polarity of the azobenzene groups,” Can. J. Chem. 72(11), 1773–1778 (1995).
[CrossRef]

Inao, Y.

T. Ito, T. Yamada, Y. Inao, T. Yamaguchi, N. Mizutani, and R. Kuroda, “Fabrication of half-pitch 32 nm resist pattern using near-field lithography with a-Si mask,” Appl. Phys. Lett. 89(3), 033113 (2006).
[CrossRef]

Ito, T.

T. Ito, T. Yamada, Y. Inao, T. Yamaguchi, N. Mizutani, and R. Kuroda, “Fabrication of half-pitch 32 nm resist pattern using near-field lithography with a-Si mask,” Appl. Phys. Lett. 89(3), 033113 (2006).
[CrossRef]

Kim, D. Y.

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

Kumar, J.

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

Kuroda, R.

T. Ito, T. Yamada, Y. Inao, T. Yamaguchi, N. Mizutani, and R. Kuroda, “Fabrication of half-pitch 32 nm resist pattern using near-field lithography with a-Si mask,” Appl. Phys. Lett. 89(3), 033113 (2006).
[CrossRef]

Li, L.

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

Liu, W.

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

Menon, R.

T. L. Andrew, H. Y. Tsai, and R. Menon, “Confining light to deep subwavelength dimensions to enable optical nanopatterning,” Science 324(5929), 917–921 (2009).
[CrossRef] [PubMed]

R. Menon, H. Y. Tsai, and S. W. Thomas, “Far-field generation of localized light fields using absorbance modulation,” Phys. Rev. Lett. 98(4), 043905 (2007).
[CrossRef] [PubMed]

R. Menon and H. I. Smith, “Absorbance-modulation optical lithography,” J. Opt. Soc. Am. A 23(9), 2290–2294 (2006).
[CrossRef] [PubMed]

Mizutani, N.

T. Ito, T. Yamada, Y. Inao, T. Yamaguchi, N. Mizutani, and R. Kuroda, “Fabrication of half-pitch 32 nm resist pattern using near-field lithography with a-Si mask,” Appl. Phys. Lett. 89(3), 033113 (2006).
[CrossRef]

Natansohn, A.

H. S. Ho, A. Natansohn, C. Barrett, and P. Rochon, “Azo polymers for reversible optical storage. 8. The effect of polarity of the azobenzene groups,” Can. J. Chem. 72(11), 1773–1778 (1995).
[CrossRef]

C. Barrett, A. Natansohn, and P. Rochon, “Cis-trans thermal isomerization rates of bound and doped azobenzenes in a series of polymers,” Chem. Mater. 7(5), 899–903 (1995).
[CrossRef]

Natansohn, A. L.

C. J. Barrett, A. L. Natansohn, and P. L. Rochon, “Mechanism of optically inscribed high-efficiency diffraction gratings in azo polymer films,” J. Phys. Chem. 100(21), 8836–8842 (1996).
[CrossRef]

Okazaki, S.

S. Okazaki, “Resolution limits of optical lithography,” J. Vac. Sci. Technol. B 9(6), 2829–2833 (1991).
[CrossRef]

Rochon, P.

C. Barrett, A. Natansohn, and P. Rochon, “Cis-trans thermal isomerization rates of bound and doped azobenzenes in a series of polymers,” Chem. Mater. 7(5), 899–903 (1995).
[CrossRef]

H. S. Ho, A. Natansohn, C. Barrett, and P. Rochon, “Azo polymers for reversible optical storage. 8. The effect of polarity of the azobenzene groups,” Can. J. Chem. 72(11), 1773–1778 (1995).
[CrossRef]

Rochon, P. L.

C. J. Barrett, A. L. Natansohn, and P. L. Rochon, “Mechanism of optically inscribed high-efficiency diffraction gratings in azo polymer films,” J. Phys. Chem. 100(21), 8836–8842 (1996).
[CrossRef]

Rytov, S. M.

S. M. Rytov, “Electromagnetic properties of a finely stratified medium,” Sov. Phys. JETP 2, 466–475 (1956).

Samuelson, L.

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

Smith, H. I.

Thomas, S. W.

R. Menon, H. Y. Tsai, and S. W. Thomas, “Far-field generation of localized light fields using absorbance modulation,” Phys. Rev. Lett. 98(4), 043905 (2007).
[CrossRef] [PubMed]

Tripathy, S. K.

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

Tsai, H. Y.

T. L. Andrew, H. Y. Tsai, and R. Menon, “Confining light to deep subwavelength dimensions to enable optical nanopatterning,” Science 324(5929), 917–921 (2009).
[CrossRef] [PubMed]

R. Menon, H. Y. Tsai, and S. W. Thomas, “Far-field generation of localized light fields using absorbance modulation,” Phys. Rev. Lett. 98(4), 043905 (2007).
[CrossRef] [PubMed]

Viswanathan, N. K.

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

Williams, J.

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

Yamada, T.

T. Ito, T. Yamada, Y. Inao, T. Yamaguchi, N. Mizutani, and R. Kuroda, “Fabrication of half-pitch 32 nm resist pattern using near-field lithography with a-Si mask,” Appl. Phys. Lett. 89(3), 033113 (2006).
[CrossRef]

Yamaguchi, T.

T. Ito, T. Yamada, Y. Inao, T. Yamaguchi, N. Mizutani, and R. Kuroda, “Fabrication of half-pitch 32 nm resist pattern using near-field lithography with a-Si mask,” Appl. Phys. Lett. 89(3), 033113 (2006).
[CrossRef]

Appl. Phys. Lett. (1)

T. Ito, T. Yamada, Y. Inao, T. Yamaguchi, N. Mizutani, and R. Kuroda, “Fabrication of half-pitch 32 nm resist pattern using near-field lithography with a-Si mask,” Appl. Phys. Lett. 89(3), 033113 (2006).
[CrossRef]

Can. J. Chem. (1)

H. S. Ho, A. Natansohn, C. Barrett, and P. Rochon, “Azo polymers for reversible optical storage. 8. The effect of polarity of the azobenzene groups,” Can. J. Chem. 72(11), 1773–1778 (1995).
[CrossRef]

Chem. Mater. (1)

C. Barrett, A. Natansohn, and P. Rochon, “Cis-trans thermal isomerization rates of bound and doped azobenzenes in a series of polymers,” Chem. Mater. 7(5), 899–903 (1995).
[CrossRef]

J. Mater. Chem. (1)

N. K. Viswanathan, D. Y. Kim, S. Bian, J. Williams, W. Liu, L. Li, L. Samuelson, J. Kumar, and S. K. Tripathy, “Surface relief structures on azo polymer films,” J. Mater. Chem. 9(9), 1941–1955 (1999).
[CrossRef]

J. Opt. Soc. Am. A (1)

J. Phys. Chem. (1)

C. J. Barrett, A. L. Natansohn, and P. L. Rochon, “Mechanism of optically inscribed high-efficiency diffraction gratings in azo polymer films,” J. Phys. Chem. 100(21), 8836–8842 (1996).
[CrossRef]

J. Vac. Sci. Technol. B (2)

S. Okazaki, “Resolution limits of optical lithography,” J. Vac. Sci. Technol. B 9(6), 2829–2833 (1991).
[CrossRef]

J. Foulkes and R. J. Blaikie, “Influence of polarization on absorbance modulated subwavelength grating structures,” J. Vac. Sci. Technol. B 27(6), 2941–2946 (2009).
[CrossRef]

Opt. Express (1)

Phys. Rev. Lett. (1)

R. Menon, H. Y. Tsai, and S. W. Thomas, “Far-field generation of localized light fields using absorbance modulation,” Phys. Rev. Lett. 98(4), 043905 (2007).
[CrossRef] [PubMed]

Science (1)

T. L. Andrew, H. Y. Tsai, and R. Menon, “Confining light to deep subwavelength dimensions to enable optical nanopatterning,” Science 324(5929), 917–921 (2009).
[CrossRef] [PubMed]

Sov. Phys. JETP (1)

S. M. Rytov, “Electromagnetic properties of a finely stratified medium,” Sov. Phys. JETP 2, 466–475 (1956).

Other (2)

COMSOL Inc, 744 Cowper Steet, Palo Alto, CA 94301, www.comsol.com .

E. Muzio, “Optical lithography cost of ownership (COO) – final report for LITG501,” SEMATECH, (2000) http://www.sematech.org/docubase/document/4014atr.pdf .

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (10)

Fig. 1
Fig. 1

In absorbance modulation interference lithography (AMIL) the AML is illumined uniformly by λ1 and by a standing wave interference pattern of λ2 resulting in large power ratios at the optical nulls. This creates transparent regions in the AML through which λ1 can expose the underlying photoresist.

Fig. 6
Fig. 6

The recording stacks used for (a) the polarization and (b) plasmonic reflector experiments.

Fig. 2
Fig. 2

Intensity profile for λ1 in the photoresist when using (a) TE, (b) TM, and (c)TM polarization with a plasmonic reflector. Line-spread function at (i) 0 nm, (ii) 20nm, and (iii) 40nm into the resist layer.

Fig. 3
Fig. 3

Diagram of the Lloyd’s mirror based AMIL system used.

Fig. 4
Fig. 4

Plot of how the intensity and intensity ratio varies with distance from the mirror along the samples surface.

Fig. 5
Fig. 5

UV-Vis spectrum of 200 nm thick film of pMAEA.

Fig. 7
Fig. 7

AFM images of samples exposed to various λ1 doses using TE polarization, TM polarization, and TM polarization with a plasmonic reflector.

Fig. 8
Fig. 8

Process latitude plots for intensity ratios of 4 and 5.

Fig. 9
Fig. 9

The formation of photoinduced surface-relief grating (SRG) during AMIL exposures. (a) Height of SRG versus the dose of λ2. (b) The height has been normalized by the λ21 intensity ratio and plotted versus the dose of λ2.

Fig. 10
Fig. 10

Change in absorption contrast during exposure due to the formation of SRGs. The contrast of this material without the SRG present is 2.3 as shown in Fig. 5.

Tables (1)

Tables Icon

Table 1 Minimum Linewidth and Process Latitude

Metrics