Modeling surface imperfections in thin films and nanostructured surfaces

Poul-Erik Hansen, J. S. Madsen, S. A. Jensen, M. H. Madsen, Mirza Karamehmedović

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Accurate scatterometry and ellipsometry characterization of non-perfect thin films and nanostructured surfaces are challenging. Imperfections like surface roughness make the associated modelling and inverse problem solution difficult due to the lack of knowledge about the imperfection on the surface. Combining measurement data from several instruments increases the knowledge of non-perfect surfaces. In this paper we investigate how to incorporate this knowledge of surface imperfection into inverse methods used in scatterometry and ellipsometry using the Rigorous Coupled Wave Analysis. Three classes of imperfections are examined. The imperfections are introduced as periodic structures with a super cell periods ten times larger than the simple grating period. Two classes of imperfections concern the grating and one class concern the substrate. It is shown that imperfections of a few nanometers can severely change the reflective response on silicon gratings. Inverse scatterometry analyses of gratings with imperfection using simulated data with white noise have been performed. The results show that scatterometry is a robust technology that is able to characterize grating imperfections provided that the imperfection class is known.
Original languageEnglish
Title of host publicationProceedings of SPIE
Number of pages5
PublisherSPIE - International Society for Optical Engineering
Publication date2017
Article number103300J
Publication statusPublished - 2017
EventModeling Aspects in Optical Metrology - Internationales Congress Center, Munich, Germany
Duration: 25 Jun 201729 Jun 2017
Conference number: 10330


ConferenceModeling Aspects in Optical Metrology
LocationInternationales Congress Center
SeriesProceedings of S P I E - International Society for Optical Engineering

Cite this

Hansen, P-E., Madsen, J. S., Jensen, S. A., Madsen, M. H., & Karamehmedović, M. (2017). Modeling surface imperfections in thin films and nanostructured surfaces. In Proceedings of SPIE (Vol. 10330). [103300J ] SPIE - International Society for Optical Engineering. Proceedings of S P I E - International Society for Optical Engineering, Vol.. 10330