Expanded beam spectro-ellipsometry for big area on-line monitoring

M. Fried, C. Major, G. Juhasz, P. Petrik, Z. Horvath

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Non-destructive analysing tools are needed at all stages of thin film process-development, especially photovoltaic (PV) development, and on production lines. In the case of thin films, layer thicknesses, micro-structure, composition, layer optical properties, and their uniformity are important parameters. An important focus is to express the dielectric functions of each component material in terms of a handful of wavelength independent parameters whose variation can cover all process variants of that material. With the resulting database, spectroscopic ellipsometry coupled with multilayer analysis can be developed for on-line point-by-point mapping and on-line line-by-line imaging. Off-line point-by-point mapping can be effective for characterization of non-uniformities in full scale PV panels or big area (even 450 mm diameter) Si-wafers in developing labs but it is slow in the on-line mode when only 15 points can be obtained (within 1 min) as a 120 cm long panel moves by the mapping station. Last years [M. Fried et al, Thin Solid Films 519, 2730 (2011)], a new instrumentation was developed that provides a line image of spectroscopic ellipsometry (wl=350-1000 nm) data. Earlier a single 30 point line image could be collected in 10 s over a 15 cm width of PV material. Recent years we have built a 30, a 45 and a 60 cm width expanded beam ellipsometer which speed is increased by 10x. Now, 1800 points can be mapped in a 1 min traverse of a 60∗120 cm PV panel or flexible roll-to-roll substrate.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
ISBN (Print)9781628416855
Publication statusPublished - 2015
EventOptical Measurement Systems for Industrial Inspection IX - Munich, Germany
Duration: Jun 22 2015Jun 25 2015


OtherOptical Measurement Systems for Industrial Inspection IX


  • mapping
  • on-line monitoring
  • spectro-ellipsometry

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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    Fried, M., Major, C., Juhasz, G., Petrik, P., & Horvath, Z. (2015). Expanded beam spectro-ellipsometry for big area on-line monitoring. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 9525). [95251S] SPIE. https://doi.org/10.1117/12.2184713