Abstract

We present a fast white-light interference method for measuring surface depth profiles at nanometer scales. Previously reported white-light profilers have relied either on path difference scanning or on spectral analysis of the reflection from a fixed interferometer. We show that by performing this spectral analysis with an imaging Fourier transform spectrometer, the high speed of spectral techniques may be combined with the simple data interpretation characteristic of the scanning method. Giving experimental results from a profiler based on this principle, we show that real-time visualization of surface profiles is possible and we report measurements with a repeatability of approximately 5 nm rms. We also demonstrate good agreement with stylus profiler measurements.

© 1998 Optical Society of America

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References

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    [CrossRef] [PubMed]
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    [CrossRef] [PubMed]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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1996

P. Sandoz, G. Tribillon, H. Perrin, “High-resolution profilometry by using phase calculation algorithms for spectroscopic analysis of white-light interferograms,” J. Mod. Opt. 43, 701–708 (1996).
[CrossRef]

1995

1994

L. Deck, P. de Groot, “High-speed noncontact profiler based on scanning white-light interferometry,” Appl. Opt. 33, 7334–7338 (1994).
[CrossRef] [PubMed]

J. Schwider, L. Zhou, “Dispersive interferometric profilometer,” Opt. Lett. 19, 995–997 (1994).
[CrossRef] [PubMed]

R. G. Sellar, J. B. Rafert, “Effects of aberrations on spatially modulated Fourier transform spectrometers,” Opt. Eng. 33, 3087–3092 (1994).
[CrossRef]

A. R. Harvey, M. Begbie, M. J. Padgett, “Stationary Fourier transform spectrometer for use as a teaching tool,” Am. J. Phys. 62, 1033–1036 (1994).
[CrossRef]

1993

1992

1991

B. L. Danielson, C. Y. Boisrobert, “Absolute optical ranging using low coherence interferometry,” Appl. Opt. 30, 2975–2979 (1991).
[CrossRef] [PubMed]

G. D. Love, J. V. Major, “The application of Edser-Butler fringes to the measurement of the spatial optical structure of liquid crystal prisms and the determination of dispersion characteristics and thickness,” J. Phys. D 24, 1708–1713 (1991).
[CrossRef]

1990

1989

1985

1984

1965

G. W. Stroke, A. T. Funkhouser, “Fourier-transform spectroscopy using holographic imaging without computing and with stationary interferometers,” Phys. Lett. 16, 272–274 (1965).
[CrossRef]

Barnes, T. H.

Begbie, M.

A. R. Harvey, M. Begbie, M. J. Padgett, “Stationary Fourier transform spectrometer for use as a teaching tool,” Am. J. Phys. 62, 1033–1036 (1994).
[CrossRef]

Boisrobert, C. Y.

Calatroni, J.

Chim, S. S. C.

Claus, R.

Cohen, F.

M. Davidson, K. Kaufman, I. Mazor, F. Cohen, “An application of interference microscopy to integrated circuit inspection,” in Integrated Circuit Metrology, Inspection and Process Control, K. M. Monahan ed., Proc. SPIE775, 233–248 (1987).
[CrossRef]

Creath, K.

Danielson, B. L.

Davidson, M.

M. Davidson, K. Kaufman, I. Mazor, F. Cohen, “An application of interference microscopy to integrated circuit inspection,” in Integrated Circuit Metrology, Inspection and Process Control, K. M. Monahan ed., Proc. SPIE775, 233–248 (1987).
[CrossRef]

de Groot, P.

Deck, L.

Dresel, T.

Funkhouser, A. T.

G. W. Stroke, A. T. Funkhouser, “Fourier-transform spectroscopy using holographic imaging without computing and with stationary interferometers,” Phys. Lett. 16, 272–274 (1965).
[CrossRef]

Goodman, J. W.

J. W. Goodman, Introduction to Fourier Optics (McGraw-Hill, New York, 1968).

Harvey, A. R.

A. R. Harvey, M. Begbie, M. J. Padgett, “Stationary Fourier transform spectrometer for use as a teaching tool,” Am. J. Phys. 62, 1033–1036 (1994).
[CrossRef]

Häusler, G.

Ikonen, E.

Junttila, M.-L.

Kaufman, K.

M. Davidson, K. Kaufman, I. Mazor, F. Cohen, “An application of interference microscopy to integrated circuit inspection,” in Integrated Circuit Metrology, Inspection and Process Control, K. M. Monahan ed., Proc. SPIE775, 233–248 (1987).
[CrossRef]

Kauppinen, J.

Kawata, S.

Kino, G. S.

Lee, B. S.

Li, T.

Love, G. D.

G. D. Love, J. V. Major, “The application of Edser-Butler fringes to the measurement of the spatial optical structure of liquid crystal prisms and the determination of dispersion characteristics and thickness,” J. Phys. D 24, 1708–1713 (1991).
[CrossRef]

Major, J. V.

G. D. Love, J. V. Major, “The application of Edser-Butler fringes to the measurement of the spatial optical structure of liquid crystal prisms and the determination of dispersion characteristics and thickness,” J. Phys. D 24, 1708–1713 (1991).
[CrossRef]

Mazor, I.

M. Davidson, K. Kaufman, I. Mazor, F. Cohen, “An application of interference microscopy to integrated circuit inspection,” in Integrated Circuit Metrology, Inspection and Process Control, K. M. Monahan ed., Proc. SPIE775, 233–248 (1987).
[CrossRef]

Minami, S.

Murphy, K.

Okamoto, T.

Padgett, M. J.

A. R. Harvey, M. Begbie, M. J. Padgett, “Stationary Fourier transform spectrometer for use as a teaching tool,” Am. J. Phys. 62, 1033–1036 (1994).
[CrossRef]

Perrin, H.

P. Sandoz, G. Tribillon, H. Perrin, “High-resolution profilometry by using phase calculation algorithms for spectroscopic analysis of white-light interferograms,” J. Mod. Opt. 43, 701–708 (1996).
[CrossRef]

Rafert, J. B.

R. G. Sellar, J. B. Rafert, “Effects of aberrations on spatially modulated Fourier transform spectrometers,” Opt. Eng. 33, 3087–3092 (1994).
[CrossRef]

Sandoz, P.

P. Sandoz, G. Tribillon, H. Perrin, “High-resolution profilometry by using phase calculation algorithms for spectroscopic analysis of white-light interferograms,” J. Mod. Opt. 43, 701–708 (1996).
[CrossRef]

J. Calatroni, P. Sandoz, G. Tribillon, “Surface profiling by means of double spectral modulation,” Appl. Opt. 32, 30–37 (1993).
[CrossRef] [PubMed]

Schwider, J.

Sellar, R. G.

R. G. Sellar, J. B. Rafert, “Effects of aberrations on spatially modulated Fourier transform spectrometers,” Opt. Eng. 33, 3087–3092 (1994).
[CrossRef]

Strand, T. C.

Stroke, G. W.

G. W. Stroke, A. T. Funkhouser, “Fourier-transform spectroscopy using holographic imaging without computing and with stationary interferometers,” Phys. Lett. 16, 272–274 (1965).
[CrossRef]

Tribillon, G.

P. Sandoz, G. Tribillon, H. Perrin, “High-resolution profilometry by using phase calculation algorithms for spectroscopic analysis of white-light interferograms,” J. Mod. Opt. 43, 701–708 (1996).
[CrossRef]

J. Calatroni, P. Sandoz, G. Tribillon, “Surface profiling by means of double spectral modulation,” Appl. Opt. 32, 30–37 (1993).
[CrossRef] [PubMed]

Venzke, H.

Wang, A.

Zhou, L.

Am. J. Phys.

A. R. Harvey, M. Begbie, M. J. Padgett, “Stationary Fourier transform spectrometer for use as a teaching tool,” Am. J. Phys. 62, 1033–1036 (1994).
[CrossRef]

Appl. Opt.

J. Mod. Opt.

P. Sandoz, G. Tribillon, H. Perrin, “High-resolution profilometry by using phase calculation algorithms for spectroscopic analysis of white-light interferograms,” J. Mod. Opt. 43, 701–708 (1996).
[CrossRef]

J. Opt. Soc. Am. A

J. Phys. D

G. D. Love, J. V. Major, “The application of Edser-Butler fringes to the measurement of the spatial optical structure of liquid crystal prisms and the determination of dispersion characteristics and thickness,” J. Phys. D 24, 1708–1713 (1991).
[CrossRef]

Opt. Eng.

R. G. Sellar, J. B. Rafert, “Effects of aberrations on spatially modulated Fourier transform spectrometers,” Opt. Eng. 33, 3087–3092 (1994).
[CrossRef]

Opt. Lett.

Phys. Lett.

G. W. Stroke, A. T. Funkhouser, “Fourier-transform spectroscopy using holographic imaging without computing and with stationary interferometers,” Phys. Lett. 16, 272–274 (1965).
[CrossRef]

Other

M. Davidson, K. Kaufman, I. Mazor, F. Cohen, “An application of interference microscopy to integrated circuit inspection,” in Integrated Circuit Metrology, Inspection and Process Control, K. M. Monahan ed., Proc. SPIE775, 233–248 (1987).
[CrossRef]

J. W. Goodman, Introduction to Fourier Optics (McGraw-Hill, New York, 1968).

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Figures (7)

Fig. 1
Fig. 1

Schematic SWLI setup (IM is an imaging system).

Fig. 2
Fig. 2

Data sets produced by (a) a SWLI profiler and (b) a FTS–SAWLI profiler.

Fig. 3
Fig. 3

FTS–SAWLI profiler: M1, M2, plane mirrors; L1, L3, cylindrical lenses; L2, spherical lens.

Fig. 4
Fig. 4

Interferograms (top) and measured profiles (bottom) from two different test surfaces. Data along the interferogram depth axes correspond to Fourier-transformed spectra from points in the input plane.

Fig. 5
Fig. 5

Experimental data from the FTS–SAWLI profiler: (a) raw data from one CCD row, (b) normalization data from the same row, and (c) calibration data.

Fig. 6
Fig. 6

(a) Surface profiles recovered from three interferograms after small translations of the reference surface. (b) Residual error between the top and the bottom profiles.

Fig. 7
Fig. 7

Comparison of optical (solid curve) and stylus profiler measurements (a) before and (b) after linear scaling.

Equations (5)

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

I σ ,   z = I r σ + I t σ + 2 I r σ I t σ 1 / 2 cos σ D ,
I z = I r + I t + 2   0 I r σ I t σ 1 / 2 cos σ D d σ ,
I σ = I r σ + I t σ + 2 I r σ I t σ 1 / 2 cos σ D 0 .
I Δ = 1 2   I 0 + 1 2 - I r σ + I t σ cos σ Δ d σ + - I r σ I t σ 1 / 2 cos σ D 0 cos σ Δ d σ ,
- I r σ I t σ 1 / 2 cos σ D 0 cos σ Δ d σ   0 I r σ I t σ 1 / 2 cos σ Δ d σ δ Δ - D 0 + δ Δ + D 0 ,

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