Research Paper: Calculation of Optical Coefficients and Thickness of TiO2 Thin Film Using the Single Wavelength Ellipsometry Method

Document Type : Research Paper

Author

Associate Professor, Department of Physics, Faculty of Sciences, University of Bu Ali Sina, Hamedan, Iran

Abstract

The optical coefficients and thickness of thin films are essential parameters in many branches of science and technology. Ellipsometry is a well-known and powerful technique for calculating the essential optical parameters of thin films, due to its accuracy and non-destructive capabilities. In this paper, a single wavelength (SW) ellipsometer which is relatively simple and inexpensive compared to other conventional ellipsometers have been designed. The light source used in this design was a He-Ne laser with wavelength of 633 nm. Rotating analyzer ellipsometry (RAE) technique at different incidence angles was used to measure the ellipsometry parameters (𝜓, Δ). The efficiency and accuracy of this method were examined by calculating the optical coefficients and thickness of TiO2 thin film (with known optical parameters). In order to increase accuracy of measurements, the ellipsometry parameters (𝜓, Δ) were acquired from different regions of the film surface. Refractive index obtained for the substrate was 1.48 and refractive index, extinction coefficient and film thickness obtained for TiO2 thin film, was 2.58, 0.04 and 49.60 nm, respectively. These results, extracted from the ellipsometry data curve fitting and employing the numerical inverse method, showed the efficiency and reliability of designed configuration.

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References

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History

  • Receive Date: 09 August 2020
  • Revise Date: 16 October 2020
  • Accept Date: 29 November 2020

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