Abstract

Often measurement tasks occur, where specimens consist of multiple layers or topography shall be examined through contaminations. Especially for unknown layer materials, it is important to measure the layer’s refractive index to compensate for the errors induced on the measurement of underlying surfaces. Chromatic Confocal Coherence Tomography is proposed as a new hybrid single-shot scheme for a simultaneous measurement of thickness and refractive index of semitransparent layers, combining chromatic confocal and interferometric information. As a proof of concept, first measurements are presented along with a short discussion about their uncertainties, where minimal layer thickness and resolution are dominated by the confocal part of the signal, that is mainly influenced by the chosen microscope objective.

© 2017 Optical Society of America

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References

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    [Crossref]
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    [Crossref] [PubMed]
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    [Crossref]
  4. A. Miks, J. Novak, and P. Novak, “Analysis of method for measuring thickness of plane-parallel plates and lenses using chromatic confocal sensor,” Appl. Opt. 49(17), 3259–3264 (2010).
    [Crossref] [PubMed]
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    [Crossref] [PubMed]
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    [Crossref]
  9. H. J. Tiziani and H. M. Uhde, “Three-dimensional analysis by a microlens-array confocal arrangement,” Appl. Opt. 33(4), 567–572 (1994).
    [Crossref] [PubMed]
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    [Crossref] [PubMed]
  11. G. S. Kino and S. S. Chim, “Mirau correlation microscopy,” Appl. Opt.,  29(26), 3775–3783 (1990).
    [Crossref] [PubMed]
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    [Crossref] [PubMed]
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    [Crossref]
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    [Crossref]
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    [Crossref] [PubMed]
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    [Crossref] [PubMed]
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    [Crossref]
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    [Crossref]
  28. https://refractiveindex.info/?shelf=3d&book=crystals&page=diamond

2015 (1)

2014 (1)

2013 (1)

T. Boettcher, W. Lyda, M. Gronle, F. Mauch, and W. Osten, “Robust signal evaluation for Chromatic Confocal Spectral Interferometry,” Proc. SPIE 8788, 87880W (2013).
[Crossref]

2012 (1)

W. Lyda, M. Gronle, D. Fleischle, F. Mauch, and W. Osten, “Advantages of chromatic-confocal spectral interferometry in comparison to chromatic confocal microscopy,” Meas. Sci. Technol.,  23(5), 054009 (2012).
[Crossref]

2010 (1)

2009 (1)

J. Na, H. Y. Choi, E. S. Choi, C. Lee, and B. H. Lee, “Self-referenced spectral interferometry for simultaneous measurements of thickness and refractive index,” Appl. Opt. 48(13), 3461–3467 (2009).
[Crossref]

2008 (4)

P. J. de Groot and X. Colonna de Lega, “Transparent film profiling and analysis by interference microscopy,” Proc. SPIE 7064, 70640I (2008).
[Crossref]

X. Colonna de Lega and P. J. de Groot, “Characterization of materials and film stacks for accurate surface topography measurement using a white-light optical profiler,” Proc. SPIE 6995, 69950P (2008).
[Crossref]

J. Garzón, T. Gharbi, and J. Meneses, “Real time determination of the optical thickness and topography of tissues by chromatic confocal microscopy,” J. Opt. A Pure Appl. Opt. 10(10), 104028 (2008).
[Crossref]

S. Kim, J. Na, M. J. Kim, and B. H. Lee, “Simultaneous measurement of refractive index and thickness by combining low-coherence interferometry and confocal optics,” Opt Express 16(8), 5516–5526 (2008).
[Crossref] [PubMed]

2006 (2)

2005 (1)

P. Hlubina, “White-light spectral interferometry to measure the effective thickness of optical elements of known dispersion,” Acta Phys. Slovaca 55(4), 387–393 (2005).

2004 (1)

2003 (1)

K. Leonhardt, U. Droste, and H. Tiziani, “Interferometry for Ellipso-Height-Topometry - Part 1: Coherence scanning on the base of spacial coherence,” Opt. - Int. J. Light Electron. Opt. 113(12), 513–519 (2003).
[Crossref]

2000 (1)

1998 (1)

1996 (2)

1994 (3)

1992 (1)

1990 (1)

1984 (1)

G. Molesini, G. Pedrini, P. Poggi, and F. Quercioli, “Focus-wavelength encoded optical profilometer,” Opt. Commun. 49(4), 229–233 (1984).
[Crossref]

1977 (1)

Achi, R.

Boettcher, T.

T. Boettcher, W. Lyda, M. Gronle, F. Mauch, and W. Osten, “Robust signal evaluation for Chromatic Confocal Spectral Interferometry,” Proc. SPIE 8788, 87880W (2013).
[Crossref]

Chim, S. S.

Choi, E. S.

J. Na, H. Y. Choi, E. S. Choi, C. Lee, and B. H. Lee, “Self-referenced spectral interferometry for simultaneous measurements of thickness and refractive index,” Appl. Opt. 48(13), 3461–3467 (2009).
[Crossref]

Choi, H. Y.

J. Na, H. Y. Choi, E. S. Choi, C. Lee, and B. H. Lee, “Self-referenced spectral interferometry for simultaneous measurements of thickness and refractive index,” Appl. Opt. 48(13), 3461–3467 (2009).
[Crossref]

Colonna de Lega, X.

P. J. de Groot and X. Colonna de Lega, “Transparent film profiling and analysis by interference microscopy,” Proc. SPIE 7064, 70640I (2008).
[Crossref]

X. Colonna de Lega and P. J. de Groot, “Characterization of materials and film stacks for accurate surface topography measurement using a white-light optical profiler,” Proc. SPIE 6995, 69950P (2008).
[Crossref]

X. Colonna de Lega, “Model-based optical metrology,” in Optical imaging and metrology, W. Osten and N. Reingand, eds. (Wiley-VCH, 2012), Chap. 13.5.2.
[Crossref]

De Groot, P.

de Groot, P. J.

X. Colonna de Lega and P. J. de Groot, “Characterization of materials and film stacks for accurate surface topography measurement using a white-light optical profiler,” Proc. SPIE 6995, 69950P (2008).
[Crossref]

P. J. de Groot and X. Colonna de Lega, “Transparent film profiling and analysis by interference microscopy,” Proc. SPIE 7064, 70640I (2008).
[Crossref]

De Lega, X. C.

Dresel, T.

Droste, U.

K. Leonhardt, U. Droste, and H. Tiziani, “Interferometry for Ellipso-Height-Topometry - Part 1: Coherence scanning on the base of spacial coherence,” Opt. - Int. J. Light Electron. Opt. 113(12), 513–519 (2003).
[Crossref]

Fleischer, M.

Fleischle, D.

W. Lyda, M. Gronle, D. Fleischle, F. Mauch, and W. Osten, “Advantages of chromatic-confocal spectral interferometry in comparison to chromatic confocal microscopy,” Meas. Sci. Technol.,  23(5), 054009 (2012).
[Crossref]

Fukano, T.

Garzón, J.

J. Garzón, T. Gharbi, and J. Meneses, “Real time determination of the optical thickness and topography of tissues by chromatic confocal microscopy,” J. Opt. A Pure Appl. Opt. 10(10), 104028 (2008).
[Crossref]

Gharbi, T.

J. Garzón, T. Gharbi, and J. Meneses, “Real time determination of the optical thickness and topography of tissues by chromatic confocal microscopy,” J. Opt. A Pure Appl. Opt. 10(10), 104028 (2008).
[Crossref]

Goedgebuer, J.

Gronle, M.

T. Boettcher, W. Lyda, M. Gronle, F. Mauch, and W. Osten, “Robust signal evaluation for Chromatic Confocal Spectral Interferometry,” Proc. SPIE 8788, 87880W (2013).
[Crossref]

W. Lyda, M. Gronle, D. Fleischle, F. Mauch, and W. Osten, “Advantages of chromatic-confocal spectral interferometry in comparison to chromatic confocal microscopy,” Meas. Sci. Technol.,  23(5), 054009 (2012).
[Crossref]

Haruna, M.

Hashimoto, M.

Häusler, G.

Hibino, K.

Hlubina, P.

P. Hlubina, “White-light spectral interferometry to measure the effective thickness of optical elements of known dispersion,” Acta Phys. Slovaca 55(4), 387–393 (2005).

Kim, M. J.

S. Kim, J. Na, M. J. Kim, and B. H. Lee, “Simultaneous measurement of refractive index and thickness by combining low-coherence interferometry and confocal optics,” Opt Express 16(8), 5516–5526 (2008).
[Crossref] [PubMed]

Kim, S.

S. Kim, J. Na, M. J. Kim, and B. H. Lee, “Simultaneous measurement of refractive index and thickness by combining low-coherence interferometry and confocal optics,” Opt Express 16(8), 5516–5526 (2008).
[Crossref] [PubMed]

Kim, Y.

Kino, G. S.

Kitagawa, K.

Körner, K.

Krämer, R. N.

Lacourt, A.

Lee, B. H.

J. Na, H. Y. Choi, E. S. Choi, C. Lee, and B. H. Lee, “Self-referenced spectral interferometry for simultaneous measurements of thickness and refractive index,” Appl. Opt. 48(13), 3461–3467 (2009).
[Crossref]

S. Kim, J. Na, M. J. Kim, and B. H. Lee, “Simultaneous measurement of refractive index and thickness by combining low-coherence interferometry and confocal optics,” Opt Express 16(8), 5516–5526 (2008).
[Crossref] [PubMed]

Lee, C.

J. Na, H. Y. Choi, E. S. Choi, C. Lee, and B. H. Lee, “Self-referenced spectral interferometry for simultaneous measurements of thickness and refractive index,” Appl. Opt. 48(13), 3461–3467 (2009).
[Crossref]

Leonhardt, K.

K. Leonhardt, U. Droste, and H. Tiziani, “Interferometry for Ellipso-Height-Topometry - Part 1: Coherence scanning on the base of spacial coherence,” Opt. - Int. J. Light Electron. Opt. 113(12), 513–519 (2003).
[Crossref]

Lyda, W.

T. Boettcher, W. Lyda, M. Gronle, F. Mauch, and W. Osten, “Robust signal evaluation for Chromatic Confocal Spectral Interferometry,” Proc. SPIE 8788, 87880W (2013).
[Crossref]

W. Lyda, M. Gronle, D. Fleischle, F. Mauch, and W. Osten, “Advantages of chromatic-confocal spectral interferometry in comparison to chromatic confocal microscopy,” Meas. Sci. Technol.,  23(5), 054009 (2012).
[Crossref]

Maruyama, H.

Mauch, F.

T. Boettcher, W. Lyda, M. Gronle, F. Mauch, and W. Osten, “Robust signal evaluation for Chromatic Confocal Spectral Interferometry,” Proc. SPIE 8788, 87880W (2013).
[Crossref]

W. Lyda, M. Gronle, D. Fleischle, F. Mauch, and W. Osten, “Advantages of chromatic-confocal spectral interferometry in comparison to chromatic confocal microscopy,” Meas. Sci. Technol.,  23(5), 054009 (2012).
[Crossref]

Meneses, J.

J. Garzón, T. Gharbi, and J. Meneses, “Real time determination of the optical thickness and topography of tissues by chromatic confocal microscopy,” J. Opt. A Pure Appl. Opt. 10(10), 104028 (2008).
[Crossref]

Miks, A.

Mitsuishi, M.

Mitsuyama, T.

Molesini, G.

G. Molesini, G. Pedrini, P. Poggi, and F. Quercioli, “Focus-wavelength encoded optical profilometer,” Opt. Commun. 49(4), 229–233 (1984).
[Crossref]

Na, J.

J. Na, H. Y. Choi, E. S. Choi, C. Lee, and B. H. Lee, “Self-referenced spectral interferometry for simultaneous measurements of thickness and refractive index,” Appl. Opt. 48(13), 3461–3467 (2009).
[Crossref]

S. Kim, J. Na, M. J. Kim, and B. H. Lee, “Simultaneous measurement of refractive index and thickness by combining low-coherence interferometry and confocal optics,” Opt Express 16(8), 5516–5526 (2008).
[Crossref] [PubMed]

Novak, J.

Novak, P.

Ohmi, M.

Osten, W.

T. Boettcher, W. Lyda, M. Gronle, F. Mauch, and W. Osten, “Robust signal evaluation for Chromatic Confocal Spectral Interferometry,” Proc. SPIE 8788, 87880W (2013).
[Crossref]

W. Lyda, M. Gronle, D. Fleischle, F. Mauch, and W. Osten, “Advantages of chromatic-confocal spectral interferometry in comparison to chromatic confocal microscopy,” Meas. Sci. Technol.,  23(5), 054009 (2012).
[Crossref]

E. Papastathopoulos, K. Körner, and W. Osten, “Chromatic confocal spectral interferometry,” Appl. Opt. 45(32), 8244–8252 (2006).
[Crossref] [PubMed]

E. Papastathopoulos, K. Körner, and W. Osten, “Chromatically dispersed interferometry with wavelet analysis,” Opt. Lett. 31(5), 589–591 (2006).
[Crossref] [PubMed]

Papastathopoulos, E.

Pedrini, G.

G. Molesini, G. Pedrini, P. Poggi, and F. Quercioli, “Focus-wavelength encoded optical profilometer,” Opt. Commun. 49(4), 229–233 (1984).
[Crossref]

Poggi, P.

G. Molesini, G. Pedrini, P. Poggi, and F. Quercioli, “Focus-wavelength encoded optical profilometer,” Opt. Commun. 49(4), 229–233 (1984).
[Crossref]

Quercioli, F.

G. Molesini, G. Pedrini, P. Poggi, and F. Quercioli, “Focus-wavelength encoded optical profilometer,” Opt. Commun. 49(4), 229–233 (1984).
[Crossref]

Schwider, J.

Sugita, N.

Tajiri, H.

Tiziani, H.

K. Leonhardt, U. Droste, and H. Tiziani, “Interferometry for Ellipso-Height-Topometry - Part 1: Coherence scanning on the base of spacial coherence,” Opt. - Int. J. Light Electron. Opt. 113(12), 513–519 (2003).
[Crossref]

Tiziani, H. J.

Uhde, H.

Uhde, H. M.

Venzke, H.

Vienot, J.

Wiegers, L.

Windecker, R.

Yamaguchi, I.

Zhou, L.

Acta Phys. Slovaca (1)

P. Hlubina, “White-light spectral interferometry to measure the effective thickness of optical elements of known dispersion,” Acta Phys. Slovaca 55(4), 387–393 (2005).

Appl. Opt. (11)

J. Na, H. Y. Choi, E. S. Choi, C. Lee, and B. H. Lee, “Self-referenced spectral interferometry for simultaneous measurements of thickness and refractive index,” Appl. Opt. 48(13), 3461–3467 (2009).
[Crossref]

J. Vienot, J. Goedgebuer, and A. Lacourt, “Space and time variables in optics and holography: recent experimental aspects,” Appl. Opt. 16(2), 454–461 (1977).
[Crossref] [PubMed]

G. S. Kino and S. S. Chim, “Mirau correlation microscopy,” Appl. Opt.,  29(26), 3775–3783 (1990).
[Crossref] [PubMed]

H. J. Tiziani and H. M. Uhde, “Three-dimensional analysis by a microlens-array confocal arrangement,” Appl. Opt. 33(4), 567–572 (1994).
[Crossref] [PubMed]

H. J. Tiziani and H. Uhde, “Three-dimensional image sensing by chromatic confocal microscopy,” Appl. Opt. 33(10), 1838–1843 (1994).
[Crossref] [PubMed]

M. Fleischer, R. Windecker, and H. J. Tiziani, “Fast algorithms for data reduction in modern optical three-dimensional profile measurement systems with MMX technology,” Appl. Opt. 39(8), 1290–1297 (2000).
[Crossref]

H. J. Tiziani, R. Achi, R. N. Krämer, and L. Wiegers, “Theoretical analysis of confocal microscopy with microlenses,” Appl. Opt. 35(1), 120–125 (1996).
[Crossref] [PubMed]

T. Dresel, G. Häusler, and H. Venzke, “Three-dimensional sensing of rough surfaces by coherence radar,” Appl. Opt. 31(7), 919–925 (1992).
[Crossref] [PubMed]

P. De Groot and X. C. De Lega, “Signal modeling for low-coherence height-scanning interference microscopy,” Appl. Opt. 43(25), 4821–4830 (2004.
[Crossref] [PubMed]

E. Papastathopoulos, K. Körner, and W. Osten, “Chromatic confocal spectral interferometry,” Appl. Opt. 45(32), 8244–8252 (2006).
[Crossref] [PubMed]

A. Miks, J. Novak, and P. Novak, “Analysis of method for measuring thickness of plane-parallel plates and lenses using chromatic confocal sensor,” Appl. Opt. 49(17), 3259–3264 (2010).
[Crossref] [PubMed]

J. Opt. A Pure Appl. Opt. (1)

J. Garzón, T. Gharbi, and J. Meneses, “Real time determination of the optical thickness and topography of tissues by chromatic confocal microscopy,” J. Opt. A Pure Appl. Opt. 10(10), 104028 (2008).
[Crossref]

Meas. Sci. Technol. (1)

W. Lyda, M. Gronle, D. Fleischle, F. Mauch, and W. Osten, “Advantages of chromatic-confocal spectral interferometry in comparison to chromatic confocal microscopy,” Meas. Sci. Technol.,  23(5), 054009 (2012).
[Crossref]

Opt Express (1)

S. Kim, J. Na, M. J. Kim, and B. H. Lee, “Simultaneous measurement of refractive index and thickness by combining low-coherence interferometry and confocal optics,” Opt Express 16(8), 5516–5526 (2008).
[Crossref] [PubMed]

Opt. - Int. J. Light Electron. Opt. (1)

K. Leonhardt, U. Droste, and H. Tiziani, “Interferometry for Ellipso-Height-Topometry - Part 1: Coherence scanning on the base of spacial coherence,” Opt. - Int. J. Light Electron. Opt. 113(12), 513–519 (2003).
[Crossref]

Opt. Commun. (1)

G. Molesini, G. Pedrini, P. Poggi, and F. Quercioli, “Focus-wavelength encoded optical profilometer,” Opt. Commun. 49(4), 229–233 (1984).
[Crossref]

Opt. Express (1)

Opt. Lett. (5)

Proc. SPIE (3)

T. Boettcher, W. Lyda, M. Gronle, F. Mauch, and W. Osten, “Robust signal evaluation for Chromatic Confocal Spectral Interferometry,” Proc. SPIE 8788, 87880W (2013).
[Crossref]

P. J. de Groot and X. Colonna de Lega, “Transparent film profiling and analysis by interference microscopy,” Proc. SPIE 7064, 70640I (2008).
[Crossref]

X. Colonna de Lega and P. J. de Groot, “Characterization of materials and film stacks for accurate surface topography measurement using a white-light optical profiler,” Proc. SPIE 6995, 69950P (2008).
[Crossref]

Other (2)

X. Colonna de Lega, “Model-based optical metrology,” in Optical imaging and metrology, W. Osten and N. Reingand, eds. (Wiley-VCH, 2012), Chap. 13.5.2.
[Crossref]

https://refractiveindex.info/?shelf=3d&book=crystals&page=diamond

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Figures (6)

Fig. 1
Fig. 1

A specimen consisting of two surfaces with refractive index n2 in between. Due to refraction, confocal measurement schemes underestimate the layer’s thickness.

Fig. 2
Fig. 2

Schematic of the CCCT setup: A SLD light source and a spectrometer detector are fibre-coupled to the sensor head, where the single-mode fibre core acts as confocal filter. A refraction compensated DOE introduces a chromatic focal separation in the object arm, while the reference arm is built achromatic.

Fig. 3
Fig. 3

Reflectivity at interface of two materials depending on refractive index n1 and change in refractive index Δn. Values below 0.2% are not considered measurable.

Fig. 4
Fig. 4

Minimal detectable confocal distance: Signals from two surfaces and the resulting added signal (dashed). a) Two identical peaks spaced such, that the intensity in between drops to 50%, allowing for COG evaluation of each peak’s upper half. b) Same distance, but one peak provides significantly lower intensity, hence the minimal detectable distance is increased.

Fig. 5
Fig. 5

CCCT signal of a 50 μm fused silica sample after subtraction of reference signal. The difference in frequency under each peak gives dint, while the peak distance after low-pass filtering is dconf.

Fig. 6
Fig. 6

Pre-evaluated signals from 100 μm diamond sample. a) Confocal channel over previously calibrated axial position. Peak distance is dconf. b) Interferometric channel (OPD). Peak distance gives dint.

Equations (5)

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

d int = d × n
d conf = d × n 1 n 2 [ 1 ( NA n 1 ) 2 ] 1 / 2 [ 1 ( NA n 2 ) 2 ] 1 / 2
d comb = { NA 2 d conf 2 [ NA 4 d conf 4 + 4 ( 1 NA 2 ) d int 2 d conf 2 ] 1 / 2 2 ( 1 NA 2 ) } 1 / 2
R = ( n 1 n 2 n 1 + n 2 ) 2
Δ z CCCT Δ z CCM i d i n i

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