Surface diffusion of Si, Ge and C adatoms on Si (001) substrate studied by the molecular dynamics simulation
Chen Zhi-Hui(陈智辉), Yu Zhong-Yuan(俞重远)†, Lu Peng-Fei(芦鹏飞), and Liu Yu-Min(刘玉敏)
Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing 100876, China Institute of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China
Abstract Depositions of Si, Ge and C atoms onto a preliminary Si (001) substrate at different temperatures are investigated by using the molecular dynamics method. The mechanism of atomic self-assembling occurring locally on the flat terraces between steps is suggested. Diffusion and arrangement patterns of adatoms at different temperatures are observed. At 900 K, the deposited atoms are more likely to form dimers in the perpendicular [110] direction due to the more favourable movement along the perpendicular [110] direction. C adatoms are more likely to break or reconstruct the dimers on the substrate surface and have larger diffusion distances than Ge and Si adatoms. Exchange between C adatoms and substrate atoms are obvious and the epitaxial thickness is small. Total potential energies of adatoms and substrate atoms involved in the simulation cell are computed. When a newly arrived adatom reaches the stable position, the potential energy of the system will decrease and the curves turns into a ladder-like shape. It is found that C adatoms can lead to more reduction of the system energy and the potential energy of the system will increase as temperature increases.
Received: 27 October 2008
Revised: 08 April 2009
Accepted manuscript online:
Fund: Project supported
by the National High Technology Research and Development Program of
China (Grant No 2009AA03Z405) and the National Natural Science
Foundation of China (Grant No 60644004).
Cite this article:
Chen Zhi-Hui(陈智辉), Yu Zhong-Yuan(俞重远), Lu Peng-Fei(芦鹏飞), and Liu Yu-Min(刘玉敏) Surface diffusion of Si, Ge and C adatoms on Si (001) substrate studied by the molecular dynamics simulation 2009 Chin. Phys. B 18 4591
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