EUV reflectometry for thickness and density determination of thin film coatings

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2012-06, Vol.107 (4), p.795-800
• Main Authors: Döring, S., Hertlein, F., Bayer, A., Mann, K.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Machines; Manufacturing; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Structure and morphology; thickness; Surfaces and Interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-012-6914-6

An EUV reflectometer for the analysis of surfaces and thin films regarding refractive index, surface roughness, and mass density at the wavelength of 12.98 nm was developed. The setup uses a laser produced plasma source with an oxygen gas puff target for the generation of narrow-band EUV radiation and a flexible Kirkpatrick–Baez optics for focusing. We present EUV reflectometry (EUVR) measurements conducted on a series of carbon thin films to determine thickness and mass density of the coatings. In case of the thickness measurements results are compared to data obtained from nondestructive standard methods, i.e., grazing incidence X-ray reflectometry and spectroscopic ellipsometry. In addition, we propose a method to deduce the mass density of a sample directly from the fitted index of refraction obtained from EUVR measurements.