Molecular Dynamics Simulation Of The Effect Of Incident Energy On The Growth Of Au/Au(111) And Cu/Si(001) Nano-film

Recently, the study of thin films is one of the most investigated fields due to itsnovel properties of optical, electromagnetic and catalytic, which make them useful in avariety of applications, from nano-photonics, chemical and biological sensors, catalysisto the medical field and electronics industry．Because the micro mechanism has a directimpact on the microstructure and surface morphology, which will further determine thespecial properties of the films. The study on the micro mechanism of the thin filmgrowth is of great significance in controlling the parameters of thin films growth andimproving the quality of thin films. Due to the nano-film growth involves theoreticalanalysis at atomic level, while the existing experiment condition cannot implementatomic tracing, to compensate for the lack of experiments, making use of computersimulation, to study the micro mechanism of the thin film growth at atomic level,provides theoretical foundation for the study of nano-films growth.In this thesis, the thin films growth, including the Au/Au（111）and the Cu/Si(001)have been simulated under three-dimensional molecular dynamics by a multi-atomicdeposition process and an open source software LAMMPS.The incident-energy effectson the thin film growth were respectively studied in detail. The main work and researchresults are as follows:For simulating the growth of the Au/Au (111) film, the atomic interactionpotential with embedded atom method was used in the simulation. The incident-energyeffects on the morphologies, the surface roughness and the layer coverage of thedeposited films have been observed and summarized. When the incident energy (Ein)alters from0.1eV to50eV, the transition of incident energy dependence occurs whenthe energy value is about25eV. The incident energy of about25eV is the sputteringthreshold of Au(111) substrate. When the incident energy is lower than25eV, allatoms are all in face-centered cubic (111) arrangement without dislocation. The surfaceroughness decreases with the increase of the incident energy. For the case of Eingreaterthan25eV, Surface roughness increases with the increase of the incident energy, andthe energetic deposition results in defects of both substrate and films.For the growth of the Cu/Si (001) film，the atomic interaction potential with modify embedded atom method was used in the simulation. The incident-energy effectson the morphologies, the interface conditions,the surface roughness and the layercoverage of the deposited films also have been observed and summarized. When theincident energy (Ein) alters from1eV to40eV, the transition of incident energydependence occurs when the energy value is about11.87eV. When the incident energyis lower than11.87eV, it is not obvious that atomic mixing at the interface and thesurface roughness decreases with the increase of the incident energy, which helps thesubstrate and films combinate. For the case of Einis greater than11.87eV, surfaceroughness increases and the interface mixing becomes fierce with the increase of theincident energy, and the energetic deposition results in sputtering. The optimal growthof energy for the Cu/Si (001) is from10eV to20eV.