Characterization Of Spin Coated Polymers In Nano-environments As A Function Of Film Thickness

Characterization of Spin Coated Polymers in Nano-environments as a Function of Film Thickness Catherine E. Beck Thesis submitted to the Faculty of the Virginia Polytechnic Institute and State University in partial fulfillment for the requirements for the degree of Master of Science in Chemistry Thomas C. Ward, Chair Alan R. Esker John G. Dillard July 26, 2001 Blacksburg, VA Keywords: Thin films, Cooperativity, Polymer Brushes Characterization of Spin Coated Polymers in Nano-environments as a Function of Film Thickness (Abstract) Catherine E. Beck Polymer applications have become more demanding as industry continuously turns to more microscopic parts. Due to the interactions of the polymer chains with the supporting surface and the air interface, the thinner films required for such applications have distinctly different properties than those of the well-defined bulk systems. The goal of the current research is to elucidate the behavior of ultrathin films. Two separate studies were performed on thin films supported on silicon wafer substrates: the first focuses on the viscoelastic cooperativity of thin films, and the second concentrates on the morphological behavior of polymer brush films. For the first study, polymethyl methacrylate films were spin coated onto silicon wafers, and the film thickness was determined using ellipsometry. A series of thin films were examined using techniques such as dielectric analysis and thermal mechanical analysis. The theory of cooperativity, which explains polymeric behavior using the intermolecular and intramolecular forces among polymer chains, was employed to understand the behavior of these thin films. Another type of thin film, a polymer brush, was investigated in the second study. Polymer brushes are formed by chemically bonding one end of many polymer chains to a substrate. The other ends