Radiation defect dynamics in Si at room temperature studied by pulsed ion beams
Radiation defect dynamics in Si at room temperature studied by pulsed ion beams
复制标题
脉冲离子束研究室温下硅的辐射缺陷动力学
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
S. Kucheyev
中科院分区：
文献类型：
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作者：
J. Wallace;S. Charnvanichborikarn;L. B. B. Aji;M. T. Myers;L. Shao;S. Kucheyev
碰撞级联热化后辐射缺陷的演变通常在电子和核材料应用感兴趣的结晶固体中稳定辐射无序的形成中起主导作用。在这里，我们探索了一种脉冲离子束方法来研究室温下用 500 keV Ne、Ar、Kr 和 Xe 离子轰击的 Si 晶体中的缺陷相互作用动力学。通过研究晶格无序（通过离子沟道监测）对束占空比被动部分的依赖性，可以直接测量缺陷相互作用的有效时间常数。有效缺陷扩散长度通过损伤对光束占空比活性部分的依赖性来揭示。结果表明，对于所有研究的情况，缺陷弛豫行为均遵循二阶动力学过程，时间常数范围为～4–13ms，扩散长度为～15–50nm。两个辐射动力学参数（时间常数和扩散长度）基本上与研究范围内的最大瞬时剂量率、总离子剂量和掺杂剂浓度无关。然而，时间常数和扩散长度都随着离子质量的增加而增加。这表明碰撞级联的密度不仅影响缺陷产生和退火效率，还影响缺陷相互作用动力学。
The evolution of radiation defects after the thermalization of collision cascades often plays the dominant role in the formation of stable radiation disorder in crystalline solids of interest to electronics and nuclear materials applications. Here, we explore a pulsed-ion-beam method to study defect interaction dynamics in Si crystals bombarded at room temperature with 500 keV Ne, Ar, Kr, and Xe ions. The effective time constant of defect interaction is measured directly by studying the dependence of lattice disorder, monitored by ion channeling, on the passive part of the beam duty cycle. The effective defect diffusion length is revealed by the dependence of damage on the active part of the beam duty cycle. Results show that the defect relaxation behavior obeys a second order kinetic process for all the cases studied, with a time constant in the range of ∼4–13 ms and a diffusion length of ∼15–50 nm. Both radiation dynamics parameters (the time constant and diffusion length) are essentially independent of the maximum instantaneous dose rate, total ion dose, and dopant concentration within the ranges studied. However, both the time constant and diffusion length increase with increasing ion mass. This demonstrates that the density of collision cascades influences not only defect production and annealing efficiencies but also the defect interaction dynamics.