Superconformal electrodeposition in submicron features.

Superconformal electrodeposition is explained based on a local growth velocity that increases with coverage of a catalytic species adsorbed on the copper-electrolyte interface. For dilute concentration of the catalyst precursor in the electrolyte, local coverage in fine features changes more due to interface area change than by accumulation from the electrolyte, yielding superconformal growth. The model is supported by experiments and simulations of copper deposition in 350-100 nm wide features, helping to explain the influence of adsorbates on roughness evolution.