Abstract

A coherent multiple imaging technique for use in optical microlithography was studied. The technique involves placing a thin Fabry–Perot etalon between the mask and the projection lens of an optical stepper. An optical lithographic computer simulation tool, Prolith/2, was used to evaluate the aerial image profile obtained for extended mask structures such as typical contact hole arrays and line–space patterns used in integrated circuit fabrication. Additionally, a set of experimental studies were performed to validate the simulation results. Enhancement of both resolution and depth of focus can be obtained simultaneously with appropriate etalon parameters.

© 2000 Optical Society of America

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References

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  1. M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, New York, 1980).
  2. M. D. Levenson, “Extending the lifetime of optical lithography technologies with wavefront engineering,” Jpn. J. Appl. Phys. 33, 6765–6773 (1994).
    [CrossRef]
  3. H. J. Levinson, W. H. Arnold, eds., Handbook of Microlithography, Micromachining, and Microfabrication. Volume 1: Microlithography, Vol. PM39 of SPIE Press Monographs and Handbooks (SPIE, Bellingham, Wash., 1997), p. 71.
  4. J. F. Chen, T. Laidig, K. E. Wampler, R. Caldwell,“Full-chip optical proximity correction with depth of focus enhancement,” Microlithography World 6(3), 5–13 (1997).
  5. H. Fukuda, T. Terasawa, S. Okazaki, “Spatial filtering for depth of focus and resolution enhancement in optical lithography,” J. Vac. Sci. Technol. B 9, 3113–3116 (1991).
    [CrossRef]
  6. Z. L. Horváth, M. Erdélyi, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, “Generation of nearly nondiffracting Bessel beams with a Fabry–Perot interferometer,” J. Opt. Soc. Am. A 14, 3009–3013 (1997).
    [CrossRef]
  7. M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
    [CrossRef]
  8. M. Erdélyi, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Simulation of coherent multiple imaging by means of pupil plane filtering in optical microlithography,” J. Opt. Soc. Am. A 16, 1909–1914 (1999).
    [CrossRef]
  9. M. Erdélyi, A. Kroyan, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Coherent multiple imaging by means of pupil plane filter,” in Optical Microlithography XII, L. Van den Hove, ed., SPIE Proc.3679, 762–771 (1999).
  10. M. Erdélyi, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Enhanced microlithography using coherent multiple imaging, international symposium on microelectronics manufacturing technologies, in Lithography for Semiconductor Manufacturing, C. A. Mack, T. Stevenson, eds., Proc. SPIE3741, 180–188 (1999).
  11. C. Mack, Inside Prolith: A Comprehensive Guide to Optical Lithography Simulation (FINLE Technologies Inc., Austin Tex., 1997).

1999

1997

J. F. Chen, T. Laidig, K. E. Wampler, R. Caldwell,“Full-chip optical proximity correction with depth of focus enhancement,” Microlithography World 6(3), 5–13 (1997).

Z. L. Horváth, M. Erdélyi, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, “Generation of nearly nondiffracting Bessel beams with a Fabry–Perot interferometer,” J. Opt. Soc. Am. A 14, 3009–3013 (1997).
[CrossRef]

M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
[CrossRef]

1994

M. D. Levenson, “Extending the lifetime of optical lithography technologies with wavefront engineering,” Jpn. J. Appl. Phys. 33, 6765–6773 (1994).
[CrossRef]

1991

H. Fukuda, T. Terasawa, S. Okazaki, “Spatial filtering for depth of focus and resolution enhancement in optical lithography,” J. Vac. Sci. Technol. B 9, 3113–3116 (1991).
[CrossRef]

Bor, Zs.

M. Erdélyi, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Simulation of coherent multiple imaging by means of pupil plane filtering in optical microlithography,” J. Opt. Soc. Am. A 16, 1909–1914 (1999).
[CrossRef]

M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
[CrossRef]

Z. L. Horváth, M. Erdélyi, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, “Generation of nearly nondiffracting Bessel beams with a Fabry–Perot interferometer,” J. Opt. Soc. Am. A 14, 3009–3013 (1997).
[CrossRef]

M. Erdélyi, A. Kroyan, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Coherent multiple imaging by means of pupil plane filter,” in Optical Microlithography XII, L. Van den Hove, ed., SPIE Proc.3679, 762–771 (1999).

M. Erdélyi, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Enhanced microlithography using coherent multiple imaging, international symposium on microelectronics manufacturing technologies, in Lithography for Semiconductor Manufacturing, C. A. Mack, T. Stevenson, eds., Proc. SPIE3741, 180–188 (1999).

Born, M.

M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, New York, 1980).

Caldwell, R.

J. F. Chen, T. Laidig, K. E. Wampler, R. Caldwell,“Full-chip optical proximity correction with depth of focus enhancement,” Microlithography World 6(3), 5–13 (1997).

Cavallaro, J. R.

Z. L. Horváth, M. Erdélyi, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, “Generation of nearly nondiffracting Bessel beams with a Fabry–Perot interferometer,” J. Opt. Soc. Am. A 14, 3009–3013 (1997).
[CrossRef]

M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
[CrossRef]

Chen, J. F.

J. F. Chen, T. Laidig, K. E. Wampler, R. Caldwell,“Full-chip optical proximity correction with depth of focus enhancement,” Microlithography World 6(3), 5–13 (1997).

Erdélyi, M.

M. Erdélyi, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Simulation of coherent multiple imaging by means of pupil plane filtering in optical microlithography,” J. Opt. Soc. Am. A 16, 1909–1914 (1999).
[CrossRef]

M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
[CrossRef]

Z. L. Horváth, M. Erdélyi, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, “Generation of nearly nondiffracting Bessel beams with a Fabry–Perot interferometer,” J. Opt. Soc. Am. A 14, 3009–3013 (1997).
[CrossRef]

M. Erdélyi, A. Kroyan, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Coherent multiple imaging by means of pupil plane filter,” in Optical Microlithography XII, L. Van den Hove, ed., SPIE Proc.3679, 762–771 (1999).

M. Erdélyi, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Enhanced microlithography using coherent multiple imaging, international symposium on microelectronics manufacturing technologies, in Lithography for Semiconductor Manufacturing, C. A. Mack, T. Stevenson, eds., Proc. SPIE3741, 180–188 (1999).

Fukuda, H.

H. Fukuda, T. Terasawa, S. Okazaki, “Spatial filtering for depth of focus and resolution enhancement in optical lithography,” J. Vac. Sci. Technol. B 9, 3113–3116 (1991).
[CrossRef]

Horváth, Z. L.

M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
[CrossRef]

Z. L. Horváth, M. Erdélyi, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, “Generation of nearly nondiffracting Bessel beams with a Fabry–Perot interferometer,” J. Opt. Soc. Am. A 14, 3009–3013 (1997).
[CrossRef]

Kroyan, A.

M. Erdélyi, A. Kroyan, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Coherent multiple imaging by means of pupil plane filter,” in Optical Microlithography XII, L. Van den Hove, ed., SPIE Proc.3679, 762–771 (1999).

Laidig, T.

J. F. Chen, T. Laidig, K. E. Wampler, R. Caldwell,“Full-chip optical proximity correction with depth of focus enhancement,” Microlithography World 6(3), 5–13 (1997).

Levenson, M. D.

M. D. Levenson, “Extending the lifetime of optical lithography technologies with wavefront engineering,” Jpn. J. Appl. Phys. 33, 6765–6773 (1994).
[CrossRef]

Mack, C.

C. Mack, Inside Prolith: A Comprehensive Guide to Optical Lithography Simulation (FINLE Technologies Inc., Austin Tex., 1997).

Okazaki, S.

H. Fukuda, T. Terasawa, S. Okazaki, “Spatial filtering for depth of focus and resolution enhancement in optical lithography,” J. Vac. Sci. Technol. B 9, 3113–3116 (1991).
[CrossRef]

Osvay, K.

M. Erdélyi, A. Kroyan, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Coherent multiple imaging by means of pupil plane filter,” in Optical Microlithography XII, L. Van den Hove, ed., SPIE Proc.3679, 762–771 (1999).

M. Erdélyi, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Enhanced microlithography using coherent multiple imaging, international symposium on microelectronics manufacturing technologies, in Lithography for Semiconductor Manufacturing, C. A. Mack, T. Stevenson, eds., Proc. SPIE3741, 180–188 (1999).

Smayling, M. C.

M. Erdélyi, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Simulation of coherent multiple imaging by means of pupil plane filtering in optical microlithography,” J. Opt. Soc. Am. A 16, 1909–1914 (1999).
[CrossRef]

M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
[CrossRef]

M. Erdélyi, A. Kroyan, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Coherent multiple imaging by means of pupil plane filter,” in Optical Microlithography XII, L. Van den Hove, ed., SPIE Proc.3679, 762–771 (1999).

M. Erdélyi, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Enhanced microlithography using coherent multiple imaging, international symposium on microelectronics manufacturing technologies, in Lithography for Semiconductor Manufacturing, C. A. Mack, T. Stevenson, eds., Proc. SPIE3741, 180–188 (1999).

Szabó, G.

M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
[CrossRef]

Z. L. Horváth, M. Erdélyi, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, “Generation of nearly nondiffracting Bessel beams with a Fabry–Perot interferometer,” J. Opt. Soc. Am. A 14, 3009–3013 (1997).
[CrossRef]

Terasawa, T.

H. Fukuda, T. Terasawa, S. Okazaki, “Spatial filtering for depth of focus and resolution enhancement in optical lithography,” J. Vac. Sci. Technol. B 9, 3113–3116 (1991).
[CrossRef]

Tittel, F. K.

M. Erdélyi, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Simulation of coherent multiple imaging by means of pupil plane filtering in optical microlithography,” J. Opt. Soc. Am. A 16, 1909–1914 (1999).
[CrossRef]

M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
[CrossRef]

Z. L. Horváth, M. Erdélyi, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, “Generation of nearly nondiffracting Bessel beams with a Fabry–Perot interferometer,” J. Opt. Soc. Am. A 14, 3009–3013 (1997).
[CrossRef]

M. Erdélyi, A. Kroyan, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Coherent multiple imaging by means of pupil plane filter,” in Optical Microlithography XII, L. Van den Hove, ed., SPIE Proc.3679, 762–771 (1999).

M. Erdélyi, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Enhanced microlithography using coherent multiple imaging, international symposium on microelectronics manufacturing technologies, in Lithography for Semiconductor Manufacturing, C. A. Mack, T. Stevenson, eds., Proc. SPIE3741, 180–188 (1999).

Wampler, K. E.

J. F. Chen, T. Laidig, K. E. Wampler, R. Caldwell,“Full-chip optical proximity correction with depth of focus enhancement,” Microlithography World 6(3), 5–13 (1997).

Wilson, W. L.

M. Erdélyi, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Simulation of coherent multiple imaging by means of pupil plane filtering in optical microlithography,” J. Opt. Soc. Am. A 16, 1909–1914 (1999).
[CrossRef]

M. Erdélyi, A. Kroyan, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Coherent multiple imaging by means of pupil plane filter,” in Optical Microlithography XII, L. Van den Hove, ed., SPIE Proc.3679, 762–771 (1999).

M. Erdélyi, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Enhanced microlithography using coherent multiple imaging, international symposium on microelectronics manufacturing technologies, in Lithography for Semiconductor Manufacturing, C. A. Mack, T. Stevenson, eds., Proc. SPIE3741, 180–188 (1999).

Wolf, E.

M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, New York, 1980).

J. Opt. Soc. Am. A

J. Vac. Sci. Technol. B

M. Erdélyi, Z. L. Horváth, G. Szabó, Zs. Bor, F. K. Tittel, J. R. Cavallaro, M. C. Smayling, “Generation of diffraction-free beams for applications in optical microlithography,” J. Vac. Sci. Technol. B 15, 287–292 (1997).
[CrossRef]

H. Fukuda, T. Terasawa, S. Okazaki, “Spatial filtering for depth of focus and resolution enhancement in optical lithography,” J. Vac. Sci. Technol. B 9, 3113–3116 (1991).
[CrossRef]

Jpn. J. Appl. Phys.

M. D. Levenson, “Extending the lifetime of optical lithography technologies with wavefront engineering,” Jpn. J. Appl. Phys. 33, 6765–6773 (1994).
[CrossRef]

Microlithography World

J. F. Chen, T. Laidig, K. E. Wampler, R. Caldwell,“Full-chip optical proximity correction with depth of focus enhancement,” Microlithography World 6(3), 5–13 (1997).

Other

M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, New York, 1980).

H. J. Levinson, W. H. Arnold, eds., Handbook of Microlithography, Micromachining, and Microfabrication. Volume 1: Microlithography, Vol. PM39 of SPIE Press Monographs and Handbooks (SPIE, Bellingham, Wash., 1997), p. 71.

M. Erdélyi, A. Kroyan, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Coherent multiple imaging by means of pupil plane filter,” in Optical Microlithography XII, L. Van den Hove, ed., SPIE Proc.3679, 762–771 (1999).

M. Erdélyi, K. Osvay, Zs. Bor, W. L. Wilson, M. C. Smayling, F. K. Tittel, “Enhanced microlithography using coherent multiple imaging, international symposium on microelectronics manufacturing technologies, in Lithography for Semiconductor Manufacturing, C. A. Mack, T. Stevenson, eds., Proc. SPIE3741, 180–188 (1999).

C. Mack, Inside Prolith: A Comprehensive Guide to Optical Lithography Simulation (FINLE Technologies Inc., Austin Tex., 1997).

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Figures (13)

Fig. 1
Fig. 1

Normalized amplitude and phase distribution of the pupil-plane filter that was used to simulate a Fabry–Perot etalon with d = 122 µm and R = 0.97.

Fig. 2
Fig. 2

Schematic view of the experimental arrangement. The Fabry–Perot etalon placed between the mask and the projection lens creates multiplied images of the mask pattern along the optical axis. The projection lens images all the virtual patterns simultaneously. The final superimposed image is magnified by two microscope objectives and is captured by a CCD camera.

Fig. 3
Fig. 3

Offset contact hole array. The CD varies from 1.0 to 0.52 µm in steps of 0.08 µm, whereas the pitch/CD size ratio remains constant.

Fig. 4
Fig. 4

Intensity distribution in the pupil-plane using contact hole arrays with different pitch size.

Fig. 5
Fig. 5

Two-dimensional simulation results through focus without filter. The depicted size of the aerial images is 7.5 µm × 15 µm. The value of defocus (Def) gives the distance between the examined and the focal plane.

Fig. 6
Fig. 6

Two-dimensional simulation results through focus with filter. The characteristics of the aerial images of patterns with different CD’s vary but do not change with focal position. In the case of pitch size at 0.84 µm the second diffraction orders are transmitted by the Fabry–Perot filter. This is the optimum case from the standpoint of both intensity loss and resolution.

Fig. 7
Fig. 7

Experimental results without (upper row) and with (lower row) filter through focus. The filter decreases the FWHM by 8%. However, the increased intensity side lobes cause undesirable interference effects. When the defocus is 8 µm, the intensities of the secondary and the main peaks become equal.

Fig. 8
Fig. 8

High-intensity secondary maxima generated by filter and optical aberrations.

Fig. 9
Fig. 9

Intensity distribution in the pupil-plane using line–space patterns with different pitch size.

Fig. 10
Fig. 10

Simulation results and experimental results of line–space patterns without filter (defocus, 0). The resolution limit of the optical system is pitch size at 1.52 µm.

Fig. 11
Fig. 11

Simulation results and experimental results with the Fabry–Perot filter (defocus, -5 µm). The periods of the patterns are doubled, since the filter blocks the zero order.

Fig. 12
Fig. 12

Simulation results and experimental results in the presence and in the absence of the Fabry–Perot filter with line–space pattern of 1.6-µm pitch. The filter significantly increases the depth of focus and enhances the resolution.

Fig. 13
Fig. 13

Source of light loss. The narrow Fabry–Perot transmission ring could transmit only a part of the first diffraction order.

Equations (5)

Equations on this page are rendered with MathJax. Learn more.

CD=k1λN.A.,
DOF=k2λN.A.2,
Ex, y=-1mx, yPfx, fy,
Pr=-R exp-iΦ1R exp-iΦ-1,
Φ=ϕ-2π2N.A.2+r22dM2,

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