INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
Copper electrodeposition onto hydrogenated Si(111) surfaces. Influence of thiourea.
Autor/es:
MA. BERNARDA QUIROGA ARGAÑARAZ; CECILIA I. VÁZQUEZ; GABRIELA I. LACCONI
Revista:
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
Editorial:
Elsevier
Referencias:
Año: 2009
ISSN:
0022-0728
Resumen:
Kinetics of initial steps of copper electrodeposition onto hydrogen terminated n- Si(111) surfaces from sulfuric acid electrolyte, was obtained using cyclic voltammetry and potentiostatic transients. Capacitance measurements at different potentials in Cu2+ ion free solutions with different thiourea concentrations were used to determine the flat band potential of n-Si(111) substrates. The analysis of the j/t transients according to existing theories indicates that copper deposition occurs by three-dimensional nucleation, followed by diffusion controlled growth of nuclei. The influence of thiourea (TU) on the initial steps of copper deposition is analyzed. The presence of thiourea produces an inhibition of the copper electrocrystallization. Adsorption of the additive on the hydrogenated substrate is evidenced by the changes observed in the flat band potential. Copper deposition kinetic from TU containing solutions corresponds to a progressive nucleation with diffusion controlled crystal growth. Nucleation rates of copper deposition for additive free and TU containing solutions are determined from the analysis of current transients at different overpotentials.