Gas phase deposition of hybrid coatings

Abstract

A new approach for depositing polymer/inorganic hybrid films using gas phase deposition technology has been developed and is the focus of this work. These films combine the high hardness and scratch resistance of inorganic SiO2 films with properties such as flexibility and toughness usually associated with softer polymeric films. The gas phase deposition process eliminates several of the key problems associated with the traditional wet chemical preparation of hybrid materials namely, a reduction in process steps and the elimination of harmful solvents from the process. In addition, gas phase deposition processes generate inherently denser materials then wet chemical processes eliminating post deposition annealing procedures that may damage the substrate. In this study, films are deposited on polycarbonate (PC) and silicon substrates using a novel plasma reactor. In this system, two gas streams, activated by separate plasmas, are combined to form a hybrid thin film. Films are grown from the precursor Tetraethoxysilane (TEOS), 1,2 Bis(trimethylsiloxy)ethane (TMSE) and Tripropylsilane (TPS) evaluated with respect to mechanical, chemical and optical properties, using scratch resistance (Taber abrasion), Methyl Ethyl Ketone (MEK), adhesion and visible transmission measurements. Structural and chemical properties of the deposited films are determined using IR spectroscopic measurements coupled with spectroscopic ellipsometry. The process chemistry and mechanisms are studied using in situ mass spectroscopy, in situ FTIR and spectroscopic ellipsometry.