Microsystem Technologies

, Volume 18, Issue 9–10, pp 1283–1288 | Cite as

Ellipsometric measurement accuracy of ultrathin lubricant thickness on magnetic head slider

Technical Paper


The quantitative analysis of lubricant transferred from disk to slider is important in understanding the interaction in head-disk interface and designing a stable head-disk system. When applying ellipsometric technology to determine the lubricant thickness on slider, the measurement accuracy is of concern due to the location-to-location variations of slider optical constants. This paper carried out a systematic and quantitative study on how the variations of slider optical constants affect the measurement accuracy of lubricant thickness. In this study, the distribution of slider optical constant was obtained; a differential method was used to calculate the uncertainty in lubricant thickness and the calculated results were experimentally verified. The results show that for the state-of-art sliders, the uncertainty in lubricant thickness is about 20 % for below 2 nm thicknesses and less than 15 % for around 3 nm thicknesses when measured at 632.8 nm wavelength. The results of this study might be also useful for the other optical instruments used to determine the amount of the transferred lubricant.


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Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  1. 1.Data Storage Institute, Agent for Science, Technology and ResearchSingaporeSingapore
  2. 2.WD Media (Singapore) Pte LtdSingaporeSingapore

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