The Interrelation between the Optical Coefficients of Ultrathin Metal Films and Their Geometric Parameters of Surface Morphology

Abstract
The theoretical and experimental data on the study of the optical coefficients of electromagnetic waves in the super high frequency range 2–4,5 GHz and their relationship with the thickness of the conductive films by the example of aluminum are presented. It is showed that transformation of the relief of a thin-film structure with an increase in the bulk mass of the deposited material causes an increase in surface roughness with a maximum of 7 nanometers. It is worth noting that exactly for these thicknesses of the studied films the maximum absorption of the incident electromagnetic wave is experimentally achieved. Meanwhile, a theoretical calculation of the reflection, transmission and absorption coefficients showed the maximum absorption of the incident wave at a thickness of 5 nm. The difference between the experimental and theoretical values of the absorptivity is explained by the non-ideal geometry of ultrathin conductive surfaces. At the thicknesses from 1 nm to 10 nm the film itself is formed in the form of separate nanoislands.

Keywords
optical coefficients, electromagnetic interaction, ultrathin structures, metal films
УДК 537.9; 549.086; 537.86.029

The Interrelation between the Optical Coefficients of Ultrathin Metal Films and Their Geometric Parameters of Surface Morphology (RUS)