Journal of The Electrochemical Society · 2009 · 23 citations · 22 references
Natural SciencesMaterials EngineeringMaterials ScienceElectrochemistrySurface ChemistrySurface ScienceElectrochemical CellsElectrode MaterialsElectrode-electrolyte InterfacesElectrolyte MaterialsElectrolyte SolutionsSurface ModificationAnodic OxidationCathodic Reaction MechanismsConcentrationDeposition RateDeposition Rate EffectsElectrochemical Surface EngineeringElectroless DepositionElectrolytic Deposition
Superconformal Cu electroless deposition is demonstrated in a CuSO4–EDTA–HCHO (where EDTA is ethylenediaminetetraacetic \nacid) electrolyte containing 2-mercapto-5-benzimidazolesulfonic acid (MBIS). MBIS reveals a concentration-dependent effect in \nthe deposition rate on planar substrates, whereby acceleration at low concentration and suppression at high concentration are \nevident. The half-cell reaction experiments show that the acceleration effect of MBIS is mainly associated with the cathodic \nreaction, while MBIS inhibits the oxidation of HCHO in the anodic reaction. The addition of MBIS offers preferential Cu \nelectroless deposition at the bottom of 500 nm wide trenches. Poly(ethylene glycol) improved the surface roughness, maintaining \nthe shape evolution of superconformal feature filling.
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