Kinetic Monte Carlo Simulation Of The Thin Film Early Growth

The thin film manufacture technology is playing a very important role nowadays. Because of complicated growing process of thin film, there are some difficulties to study thin film growth with experimental methods and theoretical analyses. The microstructure evolution of thin film have been studied in dimension of atom-cluster by computer simulation technique in this paper. There are some important applications to do deeply research on the migration, coacervation and nucleation of island, to optimize the deposition process, to enhance the characteristics of thin film.In this paper, we consider the aided exchange progress that is included in reaction limited aggregation(RLA) theory, and propose a three dimensional model using the kinetic lattice Monte Carlo method, which is based on the diffusion limited aggregation theory. We try to probe that the changes of earliest islands are influenced by varying conditions in normal system and surfactant-mediated system by this new model. The simulation parameters, such as deposition rate, substrate temperature and maximum steps that a particle is permitted to migrate on the thin film are changed to study their effects on the results of the simulation. In addition, some of the simulation results are verified by experiment of literature. A sound arithmetic is introduced by choosing proper potential function, Morse parameter. The diffusion probabilities of all active particles, including deposition particles and surfactant epitaxy particles on the surface, are taken account of. This model simulates the microstructure evolution of thin film in the earliest ages of deposition process successfully. The island density, the average size of island and the average step of atomic diffusion related to temperature and the number of deposition layer of growth are obtained. The results were analyzed by using the Molecular Dynamics method.The results of simulation indicate that deposited atom primarily nucleate and grow before the island density reached the critical size in normal system. Then deposited atom will fill in the maze and form the continuous film shapes. In surfactant-mediated system, with the temperate in creasing, the island density becomes decreasing then increasing during the same deposition rate.