Fracture toughness of freestanding copper films with a thickness of 39 nm
Fracture toughness of freestanding copper films with a thickness of 39 nm
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39 nm 厚度独立铜膜的断裂韧性
DOI：
10.1016/j.engfracmech.2018.08.019
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发表时间：
2018
影响因子：
5.4
通讯作者：
Hiroyuki Hirakata and Kohji Minoshima
中科院分区：
文献类型：
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作者：
Toshiyuki Kondo;Kazuki Hiramine;Hiroyuki Hirakata and Kohji Minoshima
对39 nm厚的铜自支撑薄膜进行了现场场发射扫描电子显微镜(FESEM)断裂韧性测试。我们开发了制备和测试超薄独立金属膜试件的断裂韧性的方法。虽然39 nm厚的铜薄膜的临界裂纹尖端张开位移(CTOD)低于100-2600 nm厚的薄膜，但当按膜厚归一化时，两种薄膜的临界裂纹尖端张开位移(CTOD)相似。归一化CTOD对薄膜厚度的无关性表明，在厚度为10 nm的薄膜中，局部断口形貌存在几何相似性。超薄膜的裂纹萌生伴随着延性断裂。
In situ field emission scanning electron microscope (FESEM) fracture toughness experiments on 39-nm-thick freestanding copper (Cu) films were conducted. We developed methods for fabricating and testing the fracture toughness of ultrathin freestanding metallic film specimens. Although 39-nm-thick Cu films showed lower critical crack tip opening displacement (CTOD) than 100–2600-nm-thick films, both films had similar critical CTODs when normalized by their film thickness. This independence of normalized CTOD on film thickness indicates that geometric similarity of local fracture morphologies exists in films with a thickness of the order of 10 nm. Crack initiation in ultrathin films was accompanied by ductile fracture.