Plastic deformation of nanometric single crystal silicon wire in AFM bending test at intermediate temperatures
Plastic deformation of nanometric single crystal silicon wire in AFM bending test at intermediate temperatures
复制标题
纳米单晶硅丝中温AFM弯曲试验中的塑性变形
DOI：
10.1109/84.993447
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
T. Tanaka
中科院分区：
文献类型：
--
作者：
T. Namazu;Y. Isono;T. Tanaka
研究了中温条件下样品尺寸和温度对纳米单晶硅丝力学性能的影响。用原子力显微镜（AFM）对纳米SCS线的力学性能进行了表征。采用AFM场增强阳极氧化和各向异性湿法刻蚀技术在硅膜片上制备了宽度为200 ~ 800 nm、厚度为255 nm的固定-固定SCS线。在295 ~ 573 K的温度范围内，在高真空中进行了SCS丝的AFM弯曲试验。SCS线的弹性模量表现出温度依赖性，但没有尺寸效应。然而，塑性性能，如临界分解剪切应力和塑性变形范围表现出明显的依赖于试样的尺寸和温度。临界分辨切应力为4.2 ~ 7.2GPa，比毫米尺度的切应力高10倍。力-位移曲线和滑移线的原子力显微镜观察还表明，纳米SCS线在373 K（非常接近室温）下诱导塑性流动。提出了一个位错模型的AFM观察的基础上，这是能够合理化的纳米样品有很大的影响，在热激活过程中的激活吉布斯自由能。
This paper focuses on revealing specimen size and temperature effects on mechanical properties of nanometric single crystal silicon (SCS) wires at intermediate temperatures. Mechanical properties of the nanometric SCS wires were characterized by bending tests with an atomic force microscope (AFM). The fixed-fixed SCS wires with widths from 200 nm to 800 nm and a thickness of 255 nm were fabricated on a silicon diaphragm by means of field-enhanced anodization with AFM and anisotropic wet etching. The AFM bending tests of the SCS wires were carried out at temperatures ranging from 295 K to 573 K in high vacuum. Elastic moduli of the SCS wires showed temperature dependence, but had no size effect. However, plastic properties such as critical resolved shear stress and plastic deformation range showed a clear dependence on both of specimen size and temperature. The critical resolved shear stress ranged from 4.2 GPa to 7.2 GPa, which was 10 times higher than that in a millimeter scale specimen. Force-displacement curves and AFM observations of the slip line also showed that plastic flow in the nanometric SCS wires was induced at 373 K, which was very close to room temperature. A dislocation model is proposed on the basis of the AFM observation, which was able to rationalize that the nanometric specimen had a large influence on the activation Gibbs free energy in the thermal activated process.