Measurement of the optical constants of Sc films in the extreme ultraviolet

The optical properties of thin Sc films deposited in ultra high vacuum conditions have been investigated in the 6.7-174.4 nm spectral range. Transmittance and multi-angle reflectance were measured in situ in the 53.6-174.4 nm spectral range and they were used to obtain the complex refractive index of Sc films at every individual wavelength investigated. Transmittance measurements were made on Sc samples that were deposited over grids coated with a support C film. The transmittance and the extinction coefficient of Sc films at wavelengths shorter than 30 nm were measured ex situ. The ex situ samples were protected with an additional top C film before removal from vacuum. The transmittance characteristics of Sc films make them a potential candidate for EUV filters.