Modification of Diamond Conditioner with V-SAM Coatings for Corrosion Prevention During Metal CMP

Abstract

In the present work, the vapor phase-self assembled monolayers made from two different precursors, 1-dodecanethiol (DT) and perfluoroctyltrichlorosilane (FOTS), were prepared on a nickel surface under optimized conditions [2]. The various properties of the coating surfaces during exposure to an aqueous solution were evaluated and compared with a bare nickel surface through electrochemical analyses such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Potentiodynamic polarization studies revealed that these coatings inhibit both anodic and cathodic reactions as both the E-corr and I-corr values of the coating surfaces decrease. An electrical equivalent circuit (EEC) model is employed to analyze the impedance data. The protection efficiency of these coatings when exposed to commercial Cu and W slurry were also evaluated. Ni with a V-SAM coating showed good corrosion resistance against Cu slurry. However, these coatings could not provide adequate protection to an underlying Ni layer against exposure to W slurry. Thus, the base Ni layer was replaced with a Ni alloy (palladium-nickel-chrome) and V-SAM coatings were prepared using the same two precursors. These coatings showed high protection efficiency, even against the highly acidic W slurry. In addition, fluorocarbons of various thicknesses deposited on Ni and Ni alloys by a plasma polymerization technique showed higher corrosion resistance to the W slurry. Contact angle measurements were also used to assess the structural integrity of the coatings.