NUCLEATION AND SURFACE MORPHOLOGY OF COBALT FILMS ELECTRODEPOSITED ON Pt/Si SUBSTRATES

Co films deposited on Pt/Si(100) surface by electrodeposition from mixed sulphate chloride baths are investigated. The influence of applied potentials on nucleation, growth and morphological properties is studied using electrochemistry, scanning electronic microscopy (SEM) and atomic force microscopy (AFM) measurements. The electrochemical techniques show a deposition peak characteristic of diffusion-limited growth. For both applied potentials, we note that deposition occurs by instantaneous nucleation and diffusion-limited growth of 3D nucleation mechanism. Morphology observations reveal the granular structure of the electrodeposited Co layers surface with the root-mean-square roughness, Rq, varied between 7.80 and 8.95 nm. The average sizes of the Co crystallites depend strongly on the film thickness and applied potentials.