摘要
纳米压痕法在确定纳米结构材料,特别是具有较大高宽比的一维纳米结构/对象的力学特性时,若纳米结构沿压入方向的等效刚度远小于针尖-样品的接触刚度,应用常规数据分析(Oliver-Pharr)模型会导致较大的测量偏差.对常规Oliver-Pharr解析模型进行了推广,以补偿一维纳米材料等效刚度对测量结果的影响,进而提出了适用于此类测量对象的通用纳米压痕分析模型,并应用于分析柱状微纳米结构的准静态压痕测量数据.实验中应用原子力显微镜(AFM)定量测量了湿法刻蚀获得的一维单晶硅柱状结构的几何参数(包括硅纳米柱的直径和长度).实验结果表明,应用常规模型分析对较大高宽比的硅纳米柱(直径386 nm,长500 nm)的压痕数据会导致大于50%的偏差.应用修正模型分析实验数据时,测量结果不受被测对象几何参数的影响,因而可以有效提高应用纳米压痕法对微纳米结构材料,特别是一维材料的测量精度.
The measurement uncertainty of depth sensing indentation technique （also referred to as nanoindentation technique） for the determination of the mechanical properties of nano-objects is subject to plenty of error sources, including sample roughness, indentation size effect （ISE） , etc. Regarding one- dimensional （1D） nano-objects with relatively large aspect ratio, it is revealed in this paper that the equivalent specimen stiffness of this kind of nano-objects becomes one of the main error sources for quan- titative nanoindentation measurement. For the purpose of improvement of the measurement uncertainty of nanoindentation testing for 1D materials, the currently available Oliver-Pharr method is further extended to compensate for the negative influence of the specimen stiffness of 1D nano-objeets. To verify the feasi- bility of this practical data interpretation method, nanoindentation tests on silicon nano-pillars with differ- ent pillar diameters were performed. The geometrical dimensions （i.e. vertical height and in-plane diam- eter, respectively） of these chemically etched nanopillars were quantitatively determined by atomic force microscopy （AFM）. Experimental results indicate that the measurement error would amount to higher than 50% for nanopillars with actual diameter of 386 nm and an aspect ratio of about 1.3 in the case of Oliver-Pharr data evaluation method being applied. In contrast, with the proposed data interpretation method for nanoindentation testing, the measurement results are no longer sensitive to the geometrical di- mensions of nanopillars.
出处
《纳米技术与精密工程》
CAS
CSCD
2014年第3期182-188,共7页
Nanotechnology and Precision Engineering
基金
欧洲计量联合研究计划资助项目(EMRP)
关键词
纳米对象
纳米柱
纳米材料测试
纳米压痕法
尺寸效应
nano-objeets
nano-pillars
nanoscale material testing
nanoindentation techqnique
sizeeffect
