Simulation of Abnormal Effect in Film Groeth Using KMC Method
ZHENG Xiao-ping1,2, ZHANG Pei-feng1,3, HE De-yan3, HAO Yuan2
1. Institute of Electronic Information Science and Technology, Lanzhou City University, Lanzhou 730070, China; 2. State Key Lab of Advanced Non-Ferrous Materials, Gansu Province, Lanzhou University of Technology, Lanzhou 730050, China; 3. School of Physics Science and Technology, Lanzhou University, Lanzhou 730000, China
摘要以扩散理论基础,建立以"基本微观过程"为核心的新模型,首次对存在表面活化剂时薄膜生长的微观过程进行KINETIC MONTE CARLO模拟。模拟发现,温度较低时沉积原子自身更容易聚集成核,这一反常效应是由于表面活化剂原子比沉积原子更容易被激活扩散造成的。活化层原子和沉积原子都会发生跨层间的扩散,交换比并非恒等于1,而是与温度、入射率、成膜厚度等多种因素有关。
Abstract:On the basis of the classic diffusion theory we have advanced a novel model,which consists of the basic micro-processes,and have simulated the growing process of surfactant-mediated epitaxial thin-film growth with the method of Kinetic Monte Carlo(KMC).The simulated results indicated that the adatoms easily aggregate to island seeds at the low temperature and the abnormal effect results from that the surfactant atoms are more easier to be activated and to diffuse than adatoms.Meanwhile,it was found that both surfactant atoms and adatoms would diffuse from one layer to another.The exchange rate is not constantly one,but is related with the substrate temperature,deposition flux,deposited depth and so on.
[1] ZHU W G,MONGEOT F B D,VALBUSA U,et al.Adatom a scending st step edges and faceting on fcc met al(110)surfaces[J].Phys Rew Lett,2004,92(10):106-102. [2] WU J,WANG E G,VARGA K,et al.Island shape selection in Pt(111)submonolayer homoepitaxy with or without CO as an adsorbate[J].Phys Rew Lett,2002,89(14),146-103. [3] ZHANG P F.ZHENG X P,HE D Y.Kinetic monte carlo simulation of Cu film growth[J].Vacuum,2004,72(4):405-410. [4] ZHANG P F,ZHENG X P,WU S P,et al.Application of computer simulation in thin-film epitaxy growth[J].Computational Materals Science,2004,30(3-4):331-336. [5] ZHANG P F,ZHENG X P,HE D Y.Monte carlo simuhtion of nucleation at the initial stage of thin film growth[J].J Keroan Phys Soc,2005,5,(46):92-95.