Microscopic Studies of Friction and Wear at the Benzotriazole/Copper Interface

Department of Chemistry, University of Houston, Houston, Texas, United States
Tribology Letters (Impact Factor: 1.74). 04/2003; 14(4):261-268. DOI: 10.1023/A:1022684918089


Interfacial friction and topographic changes at copper surfaces have been measured in situ with AFM in nitric acid and in acidic and neutral solutions of benzotriazole (BTA), a known corrosion inhibitor. In addition, changes in the thickness of the copper film have been measured ex situ using stylus profilometry as a function of solution treatment. These measurements demonstrate isotropic dissolution in 0.10 M HNO3 solutions and little change in neutral solutions of BTA. However in acidified solutions of BTA, the formation of a substantial reaction overlayer, the presence of higher interfacial friction, and the tip-mediated, localized dissolution of copper interface is observed. These measurements indicate that BTA plays a multifunctional role under acidic conditions. In the absence of mechanical action, BTA acts to passivate the surface from isotropic etching under acidic conditions. In regions of interfacial contact, the dissolution of a BTA-Cu reaction layer leads to the localized removal of copper through a tip-mediated process.

3 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: The effect of a 1H-1,2,3-triazole, 1,2,3-benzotriazole and a number of substituted benzotriazoles, namely 1-hydroxybenzotriazole, 1H-benzotriazole-1-methanol and N-(1H-benzotriazol-1-ylmethyl)-formamide, have been investigated with respect to the corrosion of iron in 1mol/l HCl and 1mol/l HClO4. The Tafel extrapolation method, linear polarization resistance and electrochemical impedance spectroscopy illustrate the inhibiting effect of all of these compounds in both acids. They are better inhibitors in 1mol/l HCl than in 1mol/l HClO4. The changes of charge transfer resistance are also indicative for adsorption and inhibition of all of these compounds. This effect increases with time up to 16h. An equivalent circuit is suggested as a model for the impedance. The adsorption of triazole-type of compounds in both acids follows a Langmuir isotherm. Molecular modeling was used to gain some insight, about structural and electronic effects in relation to the inhibiting efficiencies.
    Journal of Solid State Electrochemistry 06/2005; 9(7):483-497. DOI:10.1007/s10008-004-0584-z · 2.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We examine the effect of different anions in solutions containing benzotriazole (BTA) on the Cu removal rate during chemical mechanical planarization (CMP). In solutions containing both and BTA, the Cu removal rate is nearly a factor of twenty lower than in solutions containing either or BTA alone. As-grown BTA films from solutions containing different anions are characterized using atomic force microscopy, ellipsometry, Raman spectroscopy, mass spectrometry, and open-circuit-potential measurements. Films grown from halide-containing solutions are found to be considerably thicker than those grown from other anions. The difference in Cu removal rate correlates well with the different as-grown film thicknesses.
    12/2006; 154(1):D57-D63. DOI:10.1149/1.2393013
  • [Show abstract] [Hide abstract]
    ABSTRACT: Two novel benzotriazolyl-containing polysulfides were synthesized as a part of the efforts of molecular design. The tribological properties of the synthetic products as additives in rapeseed oil were evaluated using a four-ball machine and compared with that of diiso-butylpolysulfides (DIBPS). The copper corrosion-inhibiting performance and thermal stabilities of the additives were explored as well. The results showed that the synthetic heterocyclic polysulfides had better corrosion-inhibiting properties and thermal stability than the DIBPS. Moreover, the heterocyclic polysulfide additives can improve extreme pressure properties of rapeseed oil as well as antiwear and friction-reducing abilities. However, compared with DIBPS, the heterocyclic polysulfide additives showed a little weaker performance. Tribofilms were investigated by means of scanning electron microscopy and X-ray photoelectron spectroscopy. Surface analysis indicated that the benzotriazolyl-containing polysulfides experienced tribochemical reactions with the rubbing steel surface to generate FeS and FeS(2), which together with the chemically absorbed organic N-containing species formed a surface protective film and hence significantly reduce wear of the steel-steel frictional pair. The titled synthetic compounds could be used as promising environmentally friendly multifunctional lubricating additives.
    Journal of Tribology 01/2009; 131(1). DOI:10.1115/1.2991125 · 1.10 Impact Factor
Show more