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.
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（above500 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.
作者
Fu-Jie Zhang
Bao-Hua Zhou
Xiao Liu
Yu Song
Xu Zuo
张福杰;周保花;刘笑;宋宇;左旭(College of Electronic Information and Optical Engineering,Nankai University,Tianjin 300071,China;Microsystem and Terahertz Research Center,China Academy of Engineering Physics,Chengdu 610200,China;Institute of Electronic Engineering,China Academy of Engineering Physics,Mianyang 621999,China;Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin,Tianjin 300350,China)
基金
Project supported by the Science Challenge Project,China(Grant No.TZ2016003-1-105)
the CAEP Microsystem and THz Science and Technology Foundation,China(Grant No.CAEPMT201501).
