Molecular Dynamics Study Of Carbon-silicon Clusters Deposited On Silicon Substrat

The crystalline quality of silicon carbide(Si C)films plays a very important role in experimental and device production,yet the deposition and annealing processes have been little explored at the atomic scale.Using molecular dynamics,this paper simulates the deposition of crystalline carbon,silicon clusters on a rough-surfaced silicon substrate,followed by annealing and then polishing of the annealed surface.The main work is as follows(1)Deposition and annealing of carbon and silicon clusters on a rough silicon carbide surface.The effects of incidence rate on the surface morphology,crystallinity,surface roughness,incident atom distribution,density and vacancies of the films were investigated.The results show that the surface becomes smoother with increasing incidence rate before and after deposition,but the difference in surface roughness between film groups with different incidence rates decreases after annealing.After annealing,the film density increases with increasing cluster incidence rate,while the volume fraction of vacancies and cavities increases simultaneously.The higher the cluster incidence rate during deposition,the deeper the distribution of the incident atoms and the greater the mixing with the substrate atoms.An interesting phenomenon is observed during the high temperature relaxation phase of annealing,where the crystallisation increases first,then gradually stabilises and finally decreases as the chirality proceeds.(2)Nanopolishing was carried out on workpieces that had undergone cluster deposition and annealing processes.The effects of different polishing depths and polishing speeds on the physical properties of the workpiece(including coordination number,workpiece temperature and distribution,kinetic energy,friction coefficient,crystallisation and average height of the workpiece)were investigated separately.The results show that the polishing depth has a significant effect on the coordination number,surface morphology,friction coefficient,crystallisation effect and workpiece temperature during the polishing process.At a polishing depth of 20?,the workpiece surface was polished while maintaining the crystallisation rate.As the polishing rate increased,the coefficient of friction decreased,the workpiece temperature increased,the polishing trajectory became clearer and the crystallisation effect was relatively good at 1?/ps.This study has important implications for better understanding of nanoscale annealing for thin film deposition and guiding Si C thin film generation experiments.