Molecular Dynamics Simulation on Forming Process of Nano Contact

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As the effort is made on the downsizing of electronic devices, the element size is approaching the nano-meter scale. Especially, the forming process of contact between the elements is one of key technologies in the future electronic industry.The purpose of this project is to elucidate the mechanism and mechanics of the mechanically forming process as well as the deformation property by atomic simulations.The following simulation of aluminum contact is carried out. (1) Ab initio simulation of atomic chain where atoms aline on a direction, (2) Ab initio and EMT (Effective Medium Theory) simulation on single crystal in order to evaluate the validity of EMT potential, and (3) tensile simulation of thin wire by means of the EMT simulation. The simulation (1) reveals that the ideal strength of atomic chain is about 1nN, and the chain shows higher strength and lower elongation than the bulk. From the simulation (2), the EMT simulation reproduces very well the tensile property of disordered atomic structure (e.g. grain boundary) as well as single crystal in tension. The simulation (3) reveals the thinning process of the nano-wire. The wire deforms easily in tension by dislocations nucleation from the surface and quick relaxation. At late stage of tension, the rotation of atoms governs the deformation process. The effect of initial crystal orientation on the thinning process is also discussed.