Multiscale Molecular Dynamics Simulation of Plasma Processing: Application to Plasma Sputtering

Abstract

Molecular dynamics is an atomistic tool that is able to treat dynamics of atom/molecules/cluster assemblies mainly in the condensed and liquid phases. The goal of the present article is to provide a new methodology for describing all phenomena of plasma processing and beyond such as gas phase chemistry as well. Simulations of condensed matter and liquid processes by molecular dynamics are now readily accessible provided the interaction potentials are available, so quantitative parameters can be deduced as diffusion coefficient, etc. The situation is less clear for gas phase processes while they operate on larger space and time scales than for condensed phases and at lower specie densities. The present article is proposing a new methodology for describing plasma core interactions in taking into account experimental space and time scales. This is illustrated on a plasma sputtering process and deposition in a single simulation.

On the role of ion potential energy in low energy HiPIMS deposition: An atomistic simulation

“…The latter is only true within a fixed energy flux, otherwise the energy distribution allows gas phase collisions [10,14]. Recently, Brault [17] demonstrated the gas phase clustering using a multi-scale MD simulation, i.e. when the deposition flux travels a distance similar to that in a typical experiment, with gas phase collisions treated properly.…”

“…So far the target side simulations are focused on the sputter yield and energy distribution of ejected atoms from the target [15,16]. Recently, Brault [17] included the working gas between target and deposition sides within a multi-scale MD simulation. He suggested that the effect of the gas phase in sputter deposition is limited to the narrowing of the energy distribution as atoms travel towards the substrate.…”

Multiscale Molecular Dynamics Simulations of Fuel Cell Nanocatalyst Plasma Sputtering Growth and Deposition

“…The height of the space between the target and the electrode was chosen to mimic an experimental argon pressure of 7.5 Pa for an experimental target to substrate separation of 6.5 cm. Applying the equality of collision numbers in the simulation box and the experiment [13,18] led to a height of 120 nm and 17,388 Argon atoms. The corresponding simulation box is drawn in Figure 1.…”

“…To this end, many synthesis techniques such as plasma sputtering deposition have been investigated, including conventional magnetron, high-power impulse magnetron sputtering, and magnetron gas aggregation source depositions [4][5][6][7]. Since these deposition processes are of atomic nature, the description and insights into targeted growth processes to improve NP morphology, structure, and properties can successfully be explored using atomistic simulations, especially molecular dynamics [8][9][10][11][12][13][14][15][16]. Both growth in inert and reactive plasma environments has, thus, been shown feasible.…”

“…A better way would be to simulate the whole sputtering/deposition/growth process occurring in these techniques. A preliminary attempt has been realized considering atomic deposition, at low pressure (2.5 Pa) from conventional sputtering [13]. The simulation box included a platinum target, the plasma forming gas (argon here), and the substrate (a model porous Vulcan carbon [17] for mimicking a fuel cell uncatalyzed electrode).…”