Research on the Microstructure of Cu Thin Films Deposited on Polycrystalline Al Surfaces Using Molecular Dynamics

Material Properties: Both Al and Cu are metals with a face-centered cubic (fcc) structure, known for their excellent electrical conductivity, thermal conductivity, and ductility. Depositing Cu thin films on polycrystalline Al surfaces can create composite materials with specific properties, which are widely used in electronics, micro-electromechanical systems (MEMS), and other fields.
Significance of the Study: Investigating the microstructure using molecular dynamics can provide insights into the atomic diffusion, bonding, and grain growth during the deposition process. This can offer a theoretical basis for optimizing thin-film preparation processes and enhancing film performance.

Model Construction: Polycrystalline Al is typically used as the substrate, with models constructed to have different grain sizes and orientations. Cu atoms are then added on the Al surface to form the Cu thin film. Interatomic interactions are usually described using Lennard-Jones potentials or the Embedded Atom Method (EAM).
Simulation Parameter Settings: Appropriate temperature, pressure, and deposition rate parameters are set. For example, the deposition rate affects the diffusion and bonding of Cu atoms on the Al surface, while temperature influences atomic thermal motion and diffusion behavior.
Simulation Process: Molecular dynamics software (such as LAMMPS) is used to simulate the deposition process of Cu atoms on the Al surface, observing behaviors such as atomic diffusion, bonding, and grain growth.

Microstructure Analysis: The study examines the grain size, grain orientation, and grain boundary distribution of the Cu thin film. Simulation results show that the grain size and orientation of the Cu film are influenced by deposition conditions. For example, a higher deposition rate may lead to smaller grain sizes and more random grain orientations.
Interface Structure and Interaction: The interface structure and interaction between the Cu film and the polycrystalline Al substrate are analyzed. Molecular dynamics simulations can reveal information such as the binding energy and stress distribution of Cu and Al atoms at the interface. The atomic arrangement and interaction at the interface significantly affect the mechanical and electrical properties of the film.
Performance Prediction: Based on microstructure analysis, the mechanical and electrical properties of the Cu thin film are predicted. For example, simulations can predict the relationship between the film's hardness, electrical conductivity, and its microstructure.

Current Status: Current research on Cu thin films deposited on polycrystalline Al mainly focuses on experimental preparation and macroscopic property testing. Molecular dynamics studies are relatively limited, but some existing research has revealed the microscopic mechanisms during the deposition process through simulations.
Future Outlook: Future research can further optimize molecular dynamics models by considering more practical factors, such as the presence of impurity atoms and the surface topography of the substrate. Additionally, combining experimental results to validate the accuracy of molecular dynamics simulations can provide a more reliable theoretical basis for optimizing thin-film preparation processes.

Note: The above content is based on existing literature. As of now, there are no specific references for the latest research progress in 2025.