Radiation-enhanced self- and boron diffusion in germanium
Radiation-enhanced self- and boron diffusion in germanium
复制标题
锗中辐射增强的自扩散和硼扩散
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
E. Haller
中科院分区：
文献类型：
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作者：
S. Schneider;H. Bracht;J. Klug;J. L. Hansen;A. Larsen;D. Bougeard;E. Haller
我们报告了在515 ℃和720 ℃之间的温度下，质子辐射增强的锗（Ge）中的自扩散和硼（B）扩散的实验。通过二次离子质谱法测量的实验扩散分布的建模实现的基础上的Frenkel对反应和双折射和解离扩散机制。的数值模拟确定的Ge的非晶和B-间隙对，偏离了几个数量级的热平衡值的浓度。自间隙相关的缺陷在辐照下的优势导致增强的自和B扩散Ge。对实验剖面的分析给出了Ge中自激子（I）的扩散和BI对的热平衡浓度的数据。这些量的温度依赖性提供了迁移焓的I和BI的形成焓，与最近的原子计算结果进行比较。同时退火和辐照下Ge中的自扩散和B扩散行为强烈地受到Ge表面阻止自异质结湮灭的性质的影响。Ge表面有限的湮没效率可能是由于真空退火下有利于施主型表面态的产生，但其物理根源尚未解决。
We report experiments on proton radiation-enhanced self- and boron (B) diffusion in germanium (Ge) for temperatures between 515 ∘C and 720 ∘C. Modeling of the experimental diffusion profiles measured by means of secondary ion mass spectrometry is achieved on the basis of the Frenkel pair reaction and the interstitialcy and dissociative diffusion mechanisms. The numerical simulations ascertain concentrations of Ge interstitials and B-interstitial pairs that deviate by several orders of magnitude from their thermal equilibrium values. The dominance of self-interstitial related defects under irradiation leads to an enhanced self- and B diffusion in Ge. Analysis of the experimental profiles yields data for the diffusion of self-interstitials (I) and the thermal equilibrium concentration of BI pairs in Ge. The temperature dependence of these quantities provides the migration enthalpy of I and formation enthalpy of BI that are compared with recent results of atomistic calculations. The behavior of self- and B diffusion in Ge under concurrent annealing and irradiation is strongly affected by the property of the Ge surface to hinder the annihilation of self-interstitials. The limited annihilation efficiency of the Ge surface can be caused by donor-type surface states favored under vacuum annealing, but the physical origin remains unsolved.