中国物理B ›› 2020, Vol. 29 ›› Issue (2): 27101-027101.doi: 10.1088/1674-1056/ab5fc5

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Molecular dynamics simulation of atomic hydrogen diffusion in strained amorphous silica

Fu-Jie Zhang(张福杰), Bao-Hua Zhou(周保花), Xiao Liu(刘笑), Yu Song(宋宇), Xu Zuo(左旭)   

  1. 1 College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071, China;
    2 Microsystem and Terahertz Research Center, China Academy of Engineering Physics, Chengdu 610200, China;
    3 Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621999, China;
    4 Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin, Tianjin 300350, China
  • 收稿日期:2019-11-04 修回日期:2019-12-04 出版日期:2020-02-05 发布日期:2020-02-05
  • 通讯作者: Xu Zuo E-mail:xzuo@nankai.edu.cn
  • 基金资助:
    Project supported by the Science Challenge Project, China (Grant No. TZ2016003-1-105) and the CAEP Microsystem and THz Science and Technology Foundation, China (Grant No. CAEPMT201501).

Molecular dynamics simulation of atomic hydrogen diffusion in strained amorphous silica

Fu-Jie Zhang(张福杰)1, Bao-Hua Zhou(周保花)1, Xiao Liu(刘笑)1, Yu Song(宋宇)2,3, Xu Zuo(左旭)1,4   

  1. 1 College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071, China;
    2 Microsystem and Terahertz Research Center, China Academy of Engineering Physics, Chengdu 610200, China;
    3 Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621999, China;
    4 Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin, Tianjin 300350, China
  • Received:2019-11-04 Revised:2019-12-04 Online:2020-02-05 Published:2020-02-05
  • Contact: Xu Zuo E-mail:xzuo@nankai.edu.cn
  • Supported by:
    Project supported by the Science Challenge Project, China (Grant No. TZ2016003-1-105) and the CAEP Microsystem and THz Science and Technology Foundation, China (Grant No. CAEPMT201501).

摘要: Understanding hydrogen diffusion in amorphous SiO2 (a-SiO2), especially under strain, is of prominent importance for improving the reliability of semiconducting devices, such as metal-oxide-semiconductor field effect transistors. In this work, the diffusion of hydrogen atom in a-SiO2 under strain is simulated by using molecular dynamics (MD) with the ReaxFF force field. A defect-free a-SiO2 atomic model, of which the local structure parameters accord well with the experimental results, is established. Strain is applied by using the uniaxial tensile method, and the values of maximum strain, ultimate strength, and Young's modulus of the a-SiO2 model under different tensile rates are calculated. The diffusion of hydrogen atom is simulated by MD with the ReaxFF, and its pathway is identified to be a series of hops among local energy minima. Moreover, the calculated diffusivity and activation energy show their dependence on strain. The diffusivity is substantially enhanced by the tensile strain at a low temperature (below 500 K), but reduced at a high temperature (above 500 K). The activation energy decreases as strain increases. Our research shows that the tensile strain can have an influence on hydrogen transportation in a-SiO2, which may be utilized to improve the reliability of semiconducting devices.

关键词: molecular dynamics, tensile strain, amorphous SiO2, hydrogen diffusion

Abstract: Understanding hydrogen diffusion in amorphous SiO2 (a-SiO2), especially under strain, is of prominent importance for improving the reliability of semiconducting devices, such as metal-oxide-semiconductor field effect transistors. In this work, the diffusion of hydrogen atom in a-SiO2 under strain is simulated by using molecular dynamics (MD) with the ReaxFF force field. A defect-free a-SiO2 atomic model, of which the local structure parameters accord well with the experimental results, is established. Strain is applied by using the uniaxial tensile method, and the values of maximum strain, ultimate strength, and Young's modulus of the a-SiO2 model under different tensile rates are calculated. The diffusion of hydrogen atom is simulated by MD with the ReaxFF, and its pathway is identified to be a series of hops among local energy minima. Moreover, the calculated diffusivity and activation energy show their dependence on strain. The diffusivity is substantially enhanced by the tensile strain at a low temperature (below 500 K), but reduced at a high temperature (above 500 K). The activation energy decreases as strain increases. Our research shows that the tensile strain can have an influence on hydrogen transportation in a-SiO2, which may be utilized to improve the reliability of semiconducting devices.

Key words: molecular dynamics, tensile strain, amorphous SiO2, hydrogen diffusion

中图分类号:  (Molecular dynamics calculations (Car-Parrinello) and other numerical simulations)

  • 71.15.Pd
71.20.-b (Electron density of states and band structure of crystalline solids) 66.30.-h (Diffusion in solids) 61.72.Hh (Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.))