Simulation Study Of Oblique Incidence Ion-Beam Assisted Deposited Diamond Like Carbon Films

The growth mechanism and synthesis methods of diamond like carbon (DLC) films have attracted much attention in the fields of physics and materials science, due to their unique physical and chemical properties and potential applications. DLC films have been synthesized by using ion-beam assisted deposition method through experiments. Moreover, ion-beam assisted deposition (IBAD) can improve the film's density, hardness and adhesion to the substrate, in a certain experimental conditions. Actually, due to the complex shape of workpiece surface, there is a certain angle between the ion-beam incidence direction and the substrate of workpiece. Latest study indicated that ion-beam incidence angle greatly impacts on films structure and other properties while using IBAD method and the microstructure is of great difference under different ion-beam incident angle when the other deposition conditions are uniform. Based on MD method, interaction between atoms was described by chosen Brenner, Tersoff and Ziegler Biersack Littmark (ZBL) potentials respectively, and a computer experimental model was built that Ar ions assisted deposition at different incidence angles by which the dynamics process of C2 deposited DLC films on silicon (001)-(2×1) surface was simulated. The influence of different ion-beam incident angle on the structure of DLC films is discussed in the process of IBAD on atomic scale. The discussion focuses on the model of films surface, average density, SP3 hybridization, the Ar atoms in the films fraction under different ion-beam incidence angles, the changes of the ion-beam incidence angle as the ratio of assisted bombardment Ar ions to deposition C atoms (reach ratio) changes or as incident energy changes, and then the experiment results was compared. The results showed that horizontal kinetic energy of the incident atoms was enhanced by the oblique incident assisted ions, thereby the horizontal migration of the C atoms were also enhanced; The ratio of migration of C atoms with ion-beam oblique incidence became greater than that with vertical, however, the density of the films and SP3 hybridization fraction became smaller. The Ar atoms in the film are less by oblique incidence than incidence vertically and that improve the hardness of films. The effects on the films structure by different ion-beam incident angle with the variation of assistance/deposition atomic (Ar/C) and incident energy are different. Different structure films could be obtained in the case of the oblique incidence of ion-beam. The results are accordance with the experimental observation.