FIRST-PRINCIPLES STUDY OF THE ADSORPTION AND DIFFUSION OF O2 ON A Si(001) SURFACE
FIRST-PRINCIPLES STUDY OF THE ADSORPTION AND DIFFUSION OF O2 ON A Si(001) SURFACE
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O2在Si(001)表面吸附和扩散的第一性原理研究
DOI：
10.1142/s0218625x11014692
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Xiaogang Liang
中科院分区：
文献类型：
--
作者：
Chun Yang;Chun Yang;Chong Yang;Ping Huang;Xiaogang Liang
本文采用基于密度泛函理论的第一性原理分子动力学方法计算了O2分子在Si（001）表面上的几种初始构型。研究了键合过程、吸附能、动力学轨迹和扩散系数。结果表明，吸附过程可分为4个阶段：物理吸附阶段、化学吸附初期阶段、化学吸附后期阶段和表面稳定阶段。Si=O结构、Si-O-Si表面氧桥结构和稳定吸附结构中氧原子插入表面与第二层硅原子之间的背键的Si-O-Si氧桥结构有利于二氧化硅四面体结构的形成。我们得出结论，在物理吸附阶段的扩散系数之间的显着差异导致不同的扩散路径，这导致在硅表面氧化的早期过程中形成的两个相伴的稳定结构。
We apply a first-principles molecular-dynamics method based on the density functional theory to calculate several initial configurations of an O2 molecule adsorbed on a Si(001) surface. The bonding processing, adsorption energy, dynamic track, and diffusion coefficient are investigated. The results indicate that the adsorption process may be divided into four stages: physical adsorption, chemical adsorption early stage, chemical adsorption late stage, and the superficial stable state. The Si=O structure, the Si–O–Si surface oxygen-bridge structure, and the Si–O–Si oxygen-bridge structure where oxygen atoms are inserted into the backbonds between the surface and the second layer of silicon atoms in the stable adsorption structures, are beneficial to the formation of the silica tetrahedral structure. We conclude that the remarkable difference between the diffusion coefficients during the physical adsorption stage leads to different diffusion paths, which results in the formation of two concomitant stable structures in the early process of silicon surface oxidation.