Deposition and Sticking of Atoms in the Sub-Monolayer Regime - SUB-ML
Institution
CRP Gabriel Lippmann
Partenaire(s) :
Institut Jean Lamour, Nancy (F) ,
University of Helsinki (Finland)
Du : 01/03/2010
Au : 28/02/2013
Budget : 463 000,00€
Contact(s) :
Philipp Patrick
Summary
The sticking and reorganization of atoms in the sub-monolayer range is of great importance in the field of surface treatments, the first monolayers defining the interface structure and properties between deposited layer and substrate as well as the adhesion of this deposited layer on the substrate. In plasma deposition techniques, the balance between sputtering and deposition of matter in general, and during the initial stages of growth in particular, is governed by the species in the plasma as well as their distributions of impact energy and incidence angle on the substrate.
In the past, many studies on thin film deposition, experimental as well as simulations, have been carried out for the initial monolayers and well beyond, yet the plasma-surface interactions remain largely unexplored. In particular, molecular dynamics (MD) simulation studies of plasma deposited matter in the sub-monolayer range have been reported only for very few applications, while simulation studies on rough surfaces have not been reported at all. In the Sub-ML project, we will study the adhesion and sticking of atoms on a substrate by a multi-disciplinary approach involving numerical simulations, deposition techniques as well as surface characterization tools. The plasma by itself is not investigated in this project but it will be treated as a source of atoms / ions and small clusters.
The major parameters explored in this project include particle properties as well as substrate composition and roughness. Large-scale MD simulations making use of reactive force fields will be used to understand the atomistic processes underlying the adhesion and reorganization of atoms on the substrates. The influence of atom and cluster energies and incidence angles on sticking and surface diffusion will be investigated for different surfaces with respect to surface coverage. The MD simulations will be coupled with Density Functional Theory (DFT) calculations. DFT calculations will be used to identify adsorption sites and to parameterize the force field of the MD simulations.
Most processes related to the adsorption and sticking of atoms can be studied by the above-mentioned simulation techniques. If processes occurring on large timescales are identified, kinetic Monte Carlo simulations will be considered. The simulation results will be validated experimentally: sputter deposition and physical vapour deposition will be used to deposit matter in the sub-monolayer range. In-vacuum Scanning Probe Microscopy (SPM) and Secondary Ion Mass Spectrometry (SIMS) allow to characterize the clustering of adatoms and to calculate the total amount of matter deposited.