Multiscale Simulations of Copper Electrodeposition | |||
|
The formation of ultrafine metal films and clusters by electrochemical deposition is a critical step in fabrication of nanoscale systems including sensors, microelectronic devices, and other significant technological application for which multiscale, multiphenomena simulations are needed. The key challenge is to simulate the complex role that trace quantities of solution additives play on nucleation, growth and shape evolution of deposits. The computational time for identifying the most sensitive parameters and estimating their values requires significant computational resources. A central focus of the ITR project has therefore been development of ultrafast and reliable algorithms and software for model development, validated by experimental data. New algorithms were developed and dynamically linked for the multiscale simulation of electrochemical nucleation on irregular domains with moving boundaries. The nucleation, growth and surface chemistry of a metal electrodeposition under the influence of additives was described by an island dynamics algorithm. The transport of solution-phase species was described by a finite volume discretization of the equations for diffusion and migration with electroneutrality constraint. The solution phase was discretized in three dimensions, with the effect of explicitly describing the concentration profiles surrounding growing nuclei and fully accounting for the effects of mass transport on the surface morphology in electrochemical systems. The surface code provided the flux boundary conditions for the electrolyte transport equations, and the electrolyte code provided the surface kinetics with reactant concentrations at the electrolyte-surface interface. The two codes were linked by a semi-implicit method, which allowed reasonable stability for relatively stiff systems. These methods will be used for analysis of experimental nucleation data to estimate parameter values and uncertainties. This work is in collaboration with Professor Richard Alkire and Richard Braatz of the Department of Chemical and Biomolecular Engineering at the University of Illinois at Urbana-Champaign (links), and their research groups, and is supported by NSF (put NSF logo).
|
