中国物理B ›› 2000, Vol. 9 ›› Issue (1): 49-54.doi: 10.1088/1009-1963/9/1/010

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SIMULATION OF FRACTAL GROWTH OF THIN FILMS AT LOW TEMPERATURE

吴自勤1, 吴锋民2, 朱启鹏2, 施建青2   

  1. (1)Center of Fundamental Physics, University of Science and Technology of China, Hefei 230026, China; (2)Institute of Technical Physics, Zhejiang University of Technology, Hangzhou 310014, China
  • 收稿日期:1999-08-26 出版日期:2000-01-15 发布日期:2005-06-10
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 49672095) and the Natural Science Foundation of Zhejiang Province of China (Grant No. 198034), and the Foundation of Engineering Science Center of Zhejiang University of Tech

SIMULATION OF FRACTAL GROWTH OF THIN FILMS AT LOW TEMPERATURE

Wu Feng-min (吴锋民)a, Zhu Qi-peng (朱启鹏)a, Shi Jian-qing (施建青)a, Wu Zi-qin (吴自勤)b   

  1. a Institute of Technical Physics, Zhejiang University of Technology, Hangzhou 310014, China b Center of Fundamental Physics, University of Science and Technology of China, Hefei 230026, China; 
  • Received:1999-08-26 Online:2000-01-15 Published:2005-06-10
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 49672095) and the Natural Science Foundation of Zhejiang Province of China (Grant No. 198034), and the Foundation of Engineering Science Center of Zhejiang University of Tech

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摘要： Fractal growth of thin films at low temperature (50－175 K) is simulated by Monte Carlo method. It is shown that the thin film growth is quite different from the diffusion-limited aggregation (DLA) model when the coverage is larger than 0.1 ML. The average branch width of clusters increases with increasing temperature and it usually larger than the branch width (1.9 atom) in the classic DLA model. The average fractal dimension of clusters increases also with increasing coverage while the fractal dimension of DLA model remains constant. This difference comes from the weak screening effect during the late stage of thin film growth. The relationship between the saturation island number ns and deposition interval Δt is described in a power law: ns∝Δtγ, where γ=-0.332 is very close to the theoretical value -1/3 of rate equations from nucleation theory.

Abstract: Fractal growth of thin films at low temperature (50－175 K) is simulated by Monte Carlo method. It is shown that the thin film growth is quite different from the diffusion-limited aggregation (DLA) model when the coverage is larger than 0.1 ML. The average branch width of clusters increases with increasing temperature and it usually larger than the branch width (1.9 atom) in the classic DLA model. The average fractal dimension of clusters increases also with increasing coverage while the fractal dimension of DLA model remains constant. This difference comes from the weak screening effect during the late stage of thin film growth. The relationship between the saturation island number ns and deposition interval $\Delta t$ is described in a power law: $n_{\rm s}\propto \Delta t^{\gamma}$, where ${\gamma}$ =-0.332 is very close to the theoretical value -1/3 of rate equations from nucleation theory.

中图分类号:  (Structural modeling: serial-addition models, computer simulation)

  • 61.43.Bn
61.43.Hv (Fractals; macroscopic aggregates (including diffusion-limited Aggregates)) 68.55.A- (Nucleation and growth)