Heterogeneous and Homogeneous Nucleation of Epitaxial NiSi2 in [110] Si Nanowires

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• 作者：Yi-Chia Chou ; Wen-Wei Wu ; Chung-Yang Lee ; Chun-Yi Liu ; Lih-Juann Chen ; King-Ning Tu
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：January 20, 2011
• 年：2011
• 卷：115
• 期：2
• 页码：397-401
• 全文大小：235K
• 年卷期：v.115,no.2(January 20, 2011)
• ISSN：1932-7455

文摘

We report here both heterogeneous and homogeneous nucleation of epitaxial silicide of NiSi₂ in Si nanowires grown in [110] direction by in situ observation in high-resolution transmission electron microscopy (TEM). Owing to the excellent lattice match between Si and NiSi₂, a giant epitaxial step of 2鈭? nm wide forms at the interface between Si and NiSi₂ during the growth of the latter. The step formation results in two silicide/Si interfaces parallel to each other in TEM observations. Heterogeneous nucleation of NiSi₂ occurs at the intersection where the step meets the interfaces. However, we have also observed the epitaxial growth of NiSi₂ having a single interface with the Si, i.e., without a giant step. Homogeneous nucleation of NiSi₂ occurs on the single interface. Incubation time of heterogeneous nucleation of NiSi₂ has been measured by high-resolution video to be much shorter than that of homogeneous nucleation. The overall growth rate of NiSi₂ for the case of heterogeneous nucleation is faster than that for the case of homogeneous nucleation. Kinetic analysis of both types of nucleation is presented for a direct comparison in order to have a better understanding of the nucleation events.