Modelling Thin Film Growth In Three Dimensions By Kinetic Monte Carlo

For a long time, a considerable number of theoretical and experimental studies are focused on film growth. And such films are widely used in modern optical and electric devices, or in catalysis industry. Many properties of opt-electronic thin film depend on the film morphology, texture and microstructure. The morphology of a thin film is influenced by the atom-level growing process. STM and AFM are the main devices to study the atom-level process in experiment. At the same time, many theoretical models about thin film growth have been proposed, such as DLA and transition state etc. With development of computer and the new algorithm coming forth, simulating the growth of thin films in large scale becomes available. By simulation of thin films growth, some microscopic processes can be revealed in extreme condition, such as high temperature and high deposition rate. In this paper, we propose a three dimensional model using the kinetic lattice Monte Carlo method, in which the processes of deposition and diffusion are included. A hashing array was constructed to store the coordinates and the diffusion rates of atoms. By utilizing hashing search algorithm, the atom which will jump to an empty lattice site is soon selected. So we can simulate the growth of thin films in large scale. The three dimensional morphology and microstructures of Cu film have been investigated in this model. The effects of incident angle, the deposition rate and temperature on the morphology of films were studied in details in this paper. The results show that the columns will form when the deposition rate is high or the incident angle is large. This is in agreement with the experiment.