Evaluation of thin metal film thickness from light attenuation and multi-reflection effects on micro-Raman response

• Published in: Thin solid films 2013-06, Vol.536, p.142-146
• Main Authors: Camerlingo, C., Lisitskiy, M.P., De Stefano, L., Rea, I., Delfino, I., Lepore, M.
• Format: Article
• Language: English
• Subjects: Attenuation; Condensed matter: structure, mechanical and thermal properties; Ellipsometry; Exact sciences and technology; Film thickness; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Metal films; Micro-Raman spectroscopy; Morphology; nano-meter characterization; Nanostructure; Optical instruments, equipment and techniques; Physics; Polarimeters and ellipsometers; Spectroscopy; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Thin films; ultra-thin films; variable angle spectroscopic ellipsometry
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.04.007

An optical model for Raman response of thin metal films has been developed, taking into account attenuation effects and multi-reflections occurring at film edges. Film thickness and surface morphology of nanometer thin NbN films have been inferred in the framework of this model using micro-Raman measurements. Results have been compared with those obtained by means of spectroscopic ellipsometry. The absolute value of the thickness is determined with a precision better than 20% on nanometric scale allowing us to control surface morphology with high accuracy also on large areas. •A micro-Raman spectroscopy method for evaluating film thickness is presented.•Raman signal attenuation and multi-reflections effects in thin films were studied.•Superconductor NbN thin films on MgO substrates have been fabricated and studied.•Thin NbN films have been investigated by micro-Raman spectroscopy and ellipsometry.