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Applied Optics

Applied Optics


  • Vol. 39, Iss. 13 — May. 1, 2000
  • pp: 2107–2115

Improved vertical-scanning interferometry

Akiko Harasaki, Joanna Schmit, and James C. Wyant  »View Author Affiliations

Applied Optics, Vol. 39, Issue 13, pp. 2107-2115 (2000)

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We describe a method that combines phase-shifting and coherence-peak-sensing techniques to permit measurements with the height resolution of phase-shifting interferometry without the interval-slope limitation of λ/4 per data sample of phase-shifting interferometry. A five-frame algorithm is used to determine both the best-focus frame position and the fractional phase from the best-focus frame of the correlogram acquired through vertical scanning. The two surface profiles retrieved from the phase and the modulation contrast of the correlograms are compared in the phase-unwrapping process to remove fringe-order ambiguity.

© 2000 Optical Society of America

OCIS Codes
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(120.6650) Instrumentation, measurement, and metrology : Surface measurements, figure
(120.6660) Instrumentation, measurement, and metrology : Surface measurements, roughness
(180.3170) Microscopy : Interference microscopy

Original Manuscript: September 10, 1999
Revised Manuscript: February 4, 2000
Published: May 1, 2000

Akiko Harasaki, Joanna Schmit, and James C. Wyant, "Improved vertical-scanning interferometry," Appl. Opt. 39, 2107-2115 (2000)

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  1. K. Creath, “Phase-measurement interferometry techniques,” in Progress in Optics XXVI, E. Wolf, ed. (Elsevier, Amsterdam, The Netherlands, 1988), pp. 349–393. [CrossRef]
  2. J. E. Greivenkamp, J. H. Bruning, “Phase shifting interferometers,” in Optical Shop Testing, D. Malacara, ed. (Wiley, New York, 1992), pp. 501–598.
  3. J. Schmit, K. Creath, “Extended averaging technique for derivation of error-compensating algorithms in phase-shifting interferometry,” Appl. Opt. 34, 3610–3619 (1995). [CrossRef] [PubMed]
  4. P. de Groot, “Derivation algorithms for phase-shifting interferometry using the concept of a data-sampling window,” Appl. Opt. 34, 4723–4730 (1995). [CrossRef]
  5. J. C. Wyant, J. Schmit, “Computerized interferometric measurement of surface microstructure,” in Optical Inspection and Micromeasurements, C. Gorecki, ed., Proc. SPIE2782, 26–37 (1996). [CrossRef]
  6. Y.-Y. Cheng, J. C. Wyant, “Two-wavelength phase shifting interferometry,” Appl. Opt. 23, 4539–4543 (1984). [CrossRef]
  7. K. Creath, “Step height measurement using two-wavelength phase-shifting interferometry,” Appl. Opt. 26, 2810–2816 (1987). [CrossRef] [PubMed]
  8. J. C. Wyant, K. Creath, “Two-wavelength phase-shifting interferometer and method,” U.S. patent4,832,489 (filed 19March1986; issued 23May1989).
  9. P. J. de Groot, “Extending the unambiguous range of two-color interferometers,” Appl. Opt. 33, 5948–5953 (1994). [CrossRef] [PubMed]
  10. Rough surfaces have local steep slopes that result in narrow fringe spacings, so the condition of two detectors per fringe is easily violated. Compared with the step height, which consists of smooth surfaces and step discontinuities, the surface profile obtained by use of the two-wavelength PSI technique is less accurate.
  11. N. Balsubramanian, “Optical system for surface topography measurement,” U.S. patent4,340,306 (filed 4February1980; issued 20July1982).
  12. M. Davidson, K. Kaufman, I. Mazor, F. Cohen, “An application of an interference microscope to integrated circuit inspection and metrology,” in Integrated Circuit Microscopy: Inspection and Process Control, K. M. Monahan, ed., Proc. SPIE775, 233–247 (1987).
  13. B. S. Lee, T. C. Strand, “Profilometry with a coherence scanning microscope,” Appl. Opt. 29, 3784–3788 (1990). [CrossRef] [PubMed]
  14. G. S. Kino, S. S. C. Chim, “Mirau correlation microscope,” Appl. Opt. 29, 3775–3783 (1990). [CrossRef] [PubMed]
  15. S. S. C. Chim, G. S. Kino, “Three-dimensional image realization in interference microscopy,” Appl. Opt. 31, 2550–2553 (1992). [CrossRef] [PubMed]
  16. P. J. Caber, “Interferometric profiler for rough surfaces,” Appl. Opt. 32, 3438–3441 (1993). [CrossRef] [PubMed]
  17. L. Deck, P. de Groot, “High-speed noncontact profiler based on scanning white-light interferometry,” Appl. Opt. 33, 7334–7338 (1994). [CrossRef] [PubMed]
  18. K. G. Larkin, “Effective nonlinear algorithm for envelope detection in white light interferometry,” J. Opt. Soc. Am. A 13, 832–843 (1996). [CrossRef]
  19. C. Ai, E. L. Novak, “Centroid approach for estimating modulation peak in broad-bandwidth interferometry,” U.S. patent5,633,715 (filed 19May1996; issued 27May1997).
  20. P. Sandoz, “Wavelet transform as a processing tool in white-light interferometry,” Opt. Lett. 22, 1065–1067 (1997). [CrossRef] [PubMed]
  21. R. J. Recknagel, G. Notni, “Analysis of white light interferograms using wavelet methods,” Opt. Commun. 148, 122–128 (1998). [CrossRef]
  22. M. Hart, D. G. Vass, M. L. Begbie, “Fast surface profiling by spectral analysis of white-light interferograms with Fourier transform spectroscopy,” Appl. Opt. 37, 1764–1769 (1998). [CrossRef]
  23. A. Harasaki, J. C. Wyant, “Fringe modulation skewing effect in white light vertical scanning interferometry,” Appl. Opt. 39, 2101–2106 (2000). [CrossRef]
  24. P. Sandoz, R. Devillers, A. Plata, “Unambiguous profilometry by fringe-order identification in white-light phase-shifting interferometry,” J. Mod. Opt. 44, 519–534 (1997). [CrossRef]
  25. D. K. Cohen, P. J. Caber, C. P. Brophy, “Rough surface profiler and method,” U.S. patent5,133,601 (filed 12June1991; issued 28July1992).
  26. P. Hariharan, M. Roy, “White-light phase-stepping interferometry: measurement of the fractional interference order,” J. Mod. Opt. 42, 2357–2360 (1995). [CrossRef]
  27. Please refer to Fig. 3. The interferogram is taken every 90° (270°), which corresponds to a distance of λ̅/4 (3λ̅/4). The frame position with the largest modulation contrast (the best-focus frame position) should be found to minimize the focus error, and the fractional phase is measured from the best-focus position.
  28. P. Hariharan, B. F. Oreb, E. Eiju, “Digital phase-shifting interferometry: a simple error-compensating phase calculation algorithm,” Appl. Opt. 26, 2504–2506 (1987). [CrossRef] [PubMed]
  29. K. Creath, “Calibration of numerical aperture effects in interferometric microscope objectives,” Appl. Opt. 28, 3333–3338 (1989). [CrossRef] [PubMed]
  30. C. J. R. Sheppard, K. G. Larkin, “Effect of numerical aperture on interference fringe spacing,” Appl. Opt. 34, 4731–4734 (1995). [CrossRef] [PubMed]
  31. The coherence length of the unfiltered tungsten light source is 1.2 µm, and after the 80-nm bandpass filter at the center wavelength of 600 nm the coherence length is 2.2 µm. This coherence length (2.2 µm) is limited by the NA of the 50×objective rather than by the filter’s bandwidth.14
  32. K. Hibino, B. F. Oreb, D. I. Farrany, K. G. Larkin, “Phase shifting for nonsinusoidal waveforms with shifting errors,” J. Opt. Soc. Am. A 12, 761–768 (1995). [CrossRef]

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