Irregular bending growth of free-standing Al microwire by electromigration
Irregular bending growth of free-standing Al microwire by electromigration
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DOI：
10.1016/j.actamat.2018.07.026
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发表时间：
2018-09
期刊：
影响因子：
9.4
通讯作者：
Y. Kimura
中科院分区：
文献类型：
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作者：
Y. Kimura
电迁移（EM）可以产生独立的微纳米线，这些微纳米线偶尔会不规则地弯曲成扭结、弯曲或折叠的形状。根据电镜数据，讨论了不规则弯曲的机理。竹节结构和单晶Al微丝分别在晶界处和无晶界处发生扭结。在钢丝中发现了位错网和氧化产物簇。扭结机理主要是由于GBs的作用改变了线材的生长方向，以及团簇之间的摩擦和TiN钝化作用导致线材外径的生长速率不同。没有观察到重力引起的屈曲。高生长速率的铝微丝在孔内放电时电阻较低，这是由于沿孔周边的均匀摩擦所致。此外，低丝径使生长速率的差异最小化。因此，通过增加输入电流和衬底温度来增加线材的生长速率和线材直径的减小有利于线材的直线度。
Electromigration (EM) can generate free-standing micro- and nanowires that are occasionally irregularly bent to kinked and curved or collapsed shapes. The mechanism behind irregular bending was discussed based on electron microscopy data. Al microwires with the bamboo structure or single crystals were kinked at the grain boundaries (GBs) or at locations without GBs, respectively. Dislocation network and clusters of oxidation products were found in the wires. The kinking mechanism was attributed to the changing growth direction owing to GBs and the different growth rate of the outer circumference of the wire owing to the friction between the clusters and the TiN passivation. No buckling owing to gravity was observed. The high growth rate of Al microwires would be accompanied by low resistance in the discharge through a hole, which is attributed to the uniform friction along the periphery of the hole. In addition, the low wire diameter minimized the differences in growth rate. Hence, the increase in the growth rate of the wire by increasing the input current and substrate temperature and the decrease in the wire diameter favor wire straightness.