Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation
Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation
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利用纳米压痕技术研究 SiO2 薄膜厚度相关硬度的实验研究
DOI：
10.3390/coatings11010023
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发表时间：
2021-01-01
期刊：
影响因子：
3.4
通讯作者：
Zhao，Chunwang
中科院分区：
文献类型：
--
作者：
Zhang，Weiguang;Li，Jijun;Zhao，Chunwang
SiO2薄膜在微机电系统、集成电路和光学薄膜器件中有着广泛的应用。SiO_2薄膜的制备工艺和光学性能的研究已经取得了很大的进展，但对其力学性能的研究却很少。在此，通过原子力显微镜观察Si衬底上的500 nm厚、1000 nm厚和2000 nm厚的SiO2薄膜的表面形貌。采用纳米压痕技术测量了3种不同厚度SiO2薄膜的硬度，分析了SiO2薄膜硬度与厚度的关系。结果表明，SiO2薄膜的平均晶粒尺寸随薄膜厚度的增加而增大。对于三种不同厚度的SiO2薄膜，存在相同的相对穿透深度范围~0.4-0.5，在此范围以上可以确定不受基底影响的本征硬度。SiO2薄膜的平均本征硬度随薄膜厚度和平均晶粒尺寸的增加而降低，其变化趋势与Hall-Petch型关系相似。
SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.