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

摘要

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 surfaceunder optimized conditions [2]. The various properties of the coating surfaces during exposure to anaqueous solution were evaluated and compared with a bare nickel surface through electrochemicalanalyses such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS).Potentiodynamic polarization studies revealed that these coatings inhibit both anodic and cathodicreactions as both the Ecorr and Icorr values of the coating surfaces decrease. An electrical equivalentcircuit (EEC) model is employed to analyze the impedance data. The protection efficiency of thesecoatings when exposed to commercial Cu and W slurry were also evaluated. Ni with a V-SAM coatingshowed good corrosion resistance against Cu slurry. However, these coatings could not provideadequate protection to an underlying Ni layer against exposure to W slurry. Thus, the base Ni layerwas replaced with a Ni alloy (palladium-nickel-chrome) and V-SAM coatings were prepared using thesame two precursors. These coatings showed high protection efficiency, even against the highly acidicW slurry. In addition, fluorocarbons of various thicknesses deposited on Ni and Ni alloys by a plasmapolymerization technique showed higher corrosion resistance to the W slurry. Contact anglemeasurements were also used to assess the structural integrity of the coatings.