Fluorine in Si: Native-defect complexes and the suppression of impurity diffusion
Fluorine in Si: Native-defect complexes and the suppression of impurity diffusion
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Si 中的氟：天然缺陷复合物和抑制杂质扩散
DOI：
10.1103/physrevb.72.045219
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发表时间：
2005
影响因子：
3.7
通讯作者：
E. Napolitani
中科院分区：
文献类型：
--
作者：
G. M. Lopez;V. Fiorentini;G. Impellizzeri;S. Mirabella;E. Napolitani
受主杂质的瞬态增强扩散严重影响了小型化硅基器件中双掺杂区的实现。已经发现氟共掺杂抑制这种瞬态扩散，但这种效应的机制尚不清楚。有人提出氟-杂质或氟-缺陷相互作用可能是原因。在这里，我们澄清这一机制相结合的第一性原理理论研究的氟在硅和有目的地设计的实验硅结构含硼和氟。中心的相互作用机制是优先结合的氟硅空位悬挂键和随后形成的空位氟复合物。后者有效地作为陷阱的过量的自激，通常会导致硼瞬态增强扩散。相反，氟-硼相互作用是边缘的，不起任何重要作用。我们的研究结果也与其他观察，如本征缺陷捕获和气泡的形成是一致的。
The transient enhanced diffusion of acceptor impurities severely affects the realization of ultrahigh doping regions in miniaturized Si-based devices. Fluorine codoping has been found to suppress this transient diffusion, but the mechanism underlying this effect is not understood. It has been proposed that fluorine-impurity or fluorine\char21{}native-defect interactions may be responsible. Here we clarify this mechanism combining first-principles theoretical studies of fluorine in Si and purposely designed experiments on Si structures containing boron and fluorine. The central interaction mechanism is the preferential binding of fluorine to Si-vacancy dangling bonds and the consequent formation of vacancy-fluorine complexes. The latter effectively act as traps for the excess self-interstitials that would normally cause boron transient enhanced diffusion. Instead, fluorine-boron interactions are marginal and do not play any significant role. Our results are also consistent with other observations such as native-defect trapping and bubble formation.