Molecular dynamics simulation of vacuum-based deposition processes

Usually, the development of sputtered layer systems as well as their manufacturing are characterised by empirical methods. To change that, a simulation approach based on molecular dynamics (MD) was developed towards its use as an engineering tool for vacuum-based deposition processes. For the MD dynamic equation, boundary conditions and mesoscopic observables consistent with thermodynamics had to be formulated. The molecular interaction potentials were developed by the application of the density functional based tight binding method (DFTB). As material system, copper and silicon were chosen. Input parameters for MD simulation are the substrate temperature and the in-situ monitored data of the particle flow. So far, several copper atoms were deposited on a 2x1 reconstruction of silicon (111). With a mesoscopic stress observable a residual tensile stress of -650 MPa was measured. Due to this approach, more detailed information about nucleation, coating morphology and microscopic origin of stress formation will be obtained.