General Model of Diffusion of Interstitial Oxygen in Silicon and Germanium Crystals
General Model of Diffusion of Interstitial Oxygen in Silicon and Germanium Crystals
复制标题
硅、锗晶体中间隙氧扩散的一般模型
DOI：
10.1557/proc-864-e9.20
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
V. Gusakov
中科院分区：
文献类型：
--
作者：
V. Gusakov
用分子力学、半经验和从头算方法对硅和锗晶体在常压和高静水压下的氧扩散系数进行了理论模拟。结果表明，间隙氧原子(OI)的扩散过程受最靠近间隙氧原子(OI)的三个硅(锗)原子的最佳构型控制。活化能=2.5 9 eV，a E Si∆()a E Ge∆=2.0 5 eV和指前因子D0(Si)=0.2 8sm S，D0(Ge)=0.39sm S的计算值与实验值吻合较好，首次较好地描述了硅单晶OI扩散常数的实验温度依赖关系(T=35 0 12 0 0°C)。静水压力(P≤80kbar)导致扩散势垒线性减小(对于Si晶体，P a E P∂∆-3 eVKbar)。计算的硅单晶OI扩散系数与压力增强的氧相关热施主的初始生长符合得很好。PAC编号：66.30.Jt，31.15.Ct，81.40.Vw，87.15Vv
A theoretical modeling of the oxygen diffusivity in silicon and germanium crystals both at normal and high hydrostatic pressure has been carried out using molecular mechanics, semiempirical and ab initio methods. It was established that the diffusion process of an interstitial oxygen atom (Oi) is controlled by the optimum configuration of three silicon (germanium) atoms nearest to Oi. The calculated values of the activation energy = 2.59 eV, ( ) a E Si ∆ ( ) a E Ge ∆ = 2.05 eV and pre-exponential factor D0 (Si) = 0.28 sm s, D0 (Ge) = 0.39 sm s are in a good agreement with experimental ones and for the first time describe perfectly an experimental temperature dependence of the Oi diffusion constant in Si crystals (T=350 1200°C). Hydrostatic pressure (P≤80 kbar) results in a linear decrease of the diffusion barrier ( = -4.38 10 ( ) P a E P ∂ ∆ -3 eV kbar for Si crystals). The calculated pressure dependence of Oi diffusivity in silicon crystals agrees well with the pressure enhanced initial growth of oxygen-related thermal donors. PACS numbers: 66.30.Jt, 31.15.Ct,81.40.Vw, 87.15Vv