The Role of Viscosity on Ion Transport in Thin-layer Electrodeposition,

G. GONZALEZ; G. MARSHALL; F. V. MOLINA; S. DENGRA; H. SANCHEZ

Morphological Evolution of Electrodeposits -and- Electrochemical Processing in ULSI Fabrication and Electrodeposition of and on Semiconductors IV

The Electrochemical Society

Lugar: Washington; Año: 2004; p. 43 - 52

The effects of viscosity variation on ion transport and growth morphology, under constant electric current and convection prevailing regimes , is studied through experiments and computational modeling. The viscosity was changed through glycerol addition. Optical techniques and particle image velocimetry using micron sized particles, allowed the tracking of the convective, migration and concentration fronts and the measurement of fluid velocity.  Computational modeling is based on a macroscopic model describing the coupling of ion transport, electrostatic potential and fluid flow. Experimental results and computational modeling show that concentration and convective fronts slow down with viscosity, but their time scaling follows the same law as for pure aqueous solutions. Velocity measurements reveal that increasing viscosity the intensity of gravitoconvective motion decreases, while gravitoconvection becomes relatively stronger.