Determining thickness and refractive index from free-standing ultra-thin polymer films with spectroscopic ellipsometry
| Autor: | Michael Stadermann, Jianing Sun, James N. Hilfiker, Chantel Aracne-Ruddle, Jeffrey S. Hale, T. E. Tiwald, Philip E. Miller |
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| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Materials science business.industry Isotropy General Physics and Astronomy 02 engineering and technology Surfaces and Interfaces General Chemistry Polymer 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Wavelength Optics chemistry Ellipsometry Angle of incidence (optics) Spectroscopic ellipsometry 0210 nano-technology business Refractive index |
| Zdroj: | Applied Surface Science. 421:508-512 |
| ISSN: | 0169-4332 |
| Popis: | It is a well-known challenge to determine refractive index (n) from ultra-thin films where the thickness is less than about 10 nm [1,2]. We discovered an interesting exception to this issue while characterizing spectroscopic ellipsometry (SE) data from isotropic, free-standing polymer films. Ellipsometry analysis shows that both thickness and refractive index can be independently determined for free-standing films as thin as 5 nm. Simulations further confirm an orthogonal separation between thickness and index effects on the experimental SE data. Effects of angle of incidence and wavelength on the data and sensitivity are discussed. While others have demonstrated methods to determine refractive index from ultra-thin films [3,4], our analysis provides the first results to demonstrate high-sensitivity to the refractive index from ultra-thin layers. |
| Databáze: | OpenAIRE |
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