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Applied Optics

Applied Optics


  • Vol. 40, Iss. 25 — Sep. 1, 2001
  • pp: 4507–4513

Comparison of the Phase Metrics DFHT IV and Zygo Pegasus 2000 fly height testers

Corley W. Strunk, Christopher C. Zahn, and Paul J. Sides  »View Author Affiliations

Applied Optics, Vol. 40, Issue 25, pp. 4507-4513 (2001)

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The performance of the Phase Metrics DFHT IV (DFHT) fly height tester was compared with the performance of the Zygo Pegasus 2000 (P2000) fly height tester. The testers showed comparable repeatabilities (0.25 nm for the DFHT and 0.30 nm for the P2000) and correlated well at all points except at the center rail trailing edge. The DFHT had a measurement uncertainty of 0.76 nm at a fly height of 25 nm and 0.35 nm near contact. Similarly the P2000 exhibited an uncertainty of 1 nm at 25 nm and 0.5 nm at contact. The measurement uncertainty of the DFHT is due to calibration at a location different from the measurement location; for the P2000, it is primarily due to residual uncertainty in the correction for stress-induced birefringence in the test disk. The P2000 did not recognize the presence of small diamondlike carbon bumps on the air bearing surface. There was a consistent 3-nm absolute offset between the fly height measurements of the two testers. Neither tester possessed a clear advantage over the other in the approaching era of near-contact recording.

© 2001 Optical Society of America

OCIS Codes
(120.2130) Instrumentation, measurement, and metrology : Ellipsometry and polarimetry
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.3930) Instrumentation, measurement, and metrology : Metrological instrumentation
(120.4640) Instrumentation, measurement, and metrology : Optical instruments

Original Manuscript: November 27, 2000
Revised Manuscript: May 10, 2001
Published: September 1, 2001

Corley W. Strunk, Christopher C. Zahn, and Paul J. Sides, "Comparison of the Phase Metrics DFHT IV and Zygo Pegasus 2000 fly height testers," Appl. Opt. 40, 4507-4513 (2001)

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