The Influence of the Interaction between Silicon and Hydroxyl Radicals before the Copper Electrodeposition. Activity Changes of the Silicon Surface

Several studies have emerged in an attempt to explain the aging process which occurs in the human body, where free radicals (FR) are species involved in these alterations. Considering this subject, there is a great interest in being able to detect, quantify and control the amount of FR that human body produces at certain periods, and especially the hydroxyl radical (–OH) [[i] , [ii] ]. In this study we examined the changes in the surface activity of n-Si after its exposition to a solution containing hydroxyl radicals. Changes in the surface activity caused by the interaction between silicon and –OH radicals were characterized by analyzing the nucleation and growth mechanism (NGM) of copper on silicon electrodes. For this aim, we studied the copper deposition on: i) n-Si without exposure to hydroxyl radicals and ii) n-Si exposes at different periods of time to hydroxyl radical. It was observed a change in the copper NGM on n-Si, from 3D progressive nucleation diffusion-controlled growth (PN3D DIFF ), for the system without exposure to the –OH radical, toward 3D instantaneous nucleation diffusion-controlled growth (IN3D DIFF ), when the semiconductor substrate was exposed to the –OH radicals. In both cases analysis by the Atomic Force Microscopy (AFM) technique was performed confirming these mechanisms. [[i] ] Tomasz Rapecki, Anna M. Nowicka, Mikolaj Donten, Fritz Scholz, Zbigniew Stojek, Electrochem. Commun. 12, (2010), 1531-1534. [[ii] ] Anna Maria Nowicka, Ulrich Hasse, Mikolaj Donten, Michael Hermes, Zbigniew Jan Stojek, Fritz Scholz, J Solid State Electrochem., 15 , (2011), 2141–2147.