Abstract

The morphology and optical properties of PMMA thin films deposited on silicon substrates were investigated. The spin coated films were characterized by atomic force microscopy and spectroscopic ellipsometry. Regardless that, the samples were deposited at different coating speeds, the surface structures of all PMMA thin films were consistent, and found to be relatively smooth, with a mean grain size in the range of 13-25 nm. The refractive index as well as the extinction coefficient of the films was determined using spectroscopic ellipsometry data over the wavelength range 380-750 nm. For this purpose, we used the Cauchy dispersion relation in order to represent PMMA layers, and then models were built by adding a roughness layer, which simply corrects any possible deviation from planarity. Besides, the thicknesses of all four films were calculated simultaneously based on multiple sample analysis method. By using this method, optical properties were coupled in such way that, the optical constants for all samples were assumed to be identical.

This work is licensed under a Creative Commons Attribution 4.0 License.