摘要
通过对TiN/SiC、TiN/TiB_2和TiN/SiO_2纳米多层膜微结构和力学性能的研究,展示了通常溅射沉积态为非晶的SiC、TiB_2和SiO_2薄膜,在立方结构的TiN晶体层模板作用下的晶化现象,以及多层膜由此产生的生长结构和力学性能的变化．结果表明：SiC在层厚≤0．6nm时晶化为立方结构后,可以反过来促进TiN/SiC多层膜中TiN层的晶体完整性；TiB_2在层厚≤2．9nm时晶化为六方结构,并与TiN形成{111}TiN//{0001}TiB_2,<100>TiN//<11(?)0>TiB_2的共格关系；SiO_2在层厚≤0．9nm时晶化为立方结构的赝晶．多层膜中SiC、TiB_2和SiO_2品化后都与TiN形成共格外延的生长结构,并相应产生了硬度升高的超硬效应．随着SiC、TiB_2和SiO_2层厚的增加,它们又转变为非晶态,多层膜的共格外延生长受到破坏,其硬度亦明显降低．
Template-induced epitaxial crystallization of SiC, TiB2 and SiO2 in TiN/SiC, TiN/TiB2 and TiN/SiO2 aaao-multilayer films and its influence on mechanical properties of the corresponding films were investigated. Results reveal that amorphous SiC, TiB2 and SiO2, which are more favorable under sputtering conditions, crystallize at smaller layer thicknesses due to the template effect of c-TiN layers. In particular, SiC crystallizes out in the face-centered cubic structure when its thickness is less than 0.6nm, which improves the crystal quality and structural integrity of the films; While TiB2, with thickness less than 2.9nm, forms hcp structure. The epitaxial orientation relationship between TiN and TiB2 is {111}TiN//{0001}TiB2, 〈 100 〉TiN // 〈 112^-0 〉WiB2; SiO2, different from the above two, forms fcc pseudo-crystalline structure under a thickness of 0.9nm. With the crystallization of SiC, TiB2 and SiO2, hardness anomalous enhancement, i.e. superhardness effect, appears in those films. This phenomenon of hardness enhancement disappears rapidly when further increase the thickness of SiC, TiB2 and SiO2 layers, and at the same time, crystallines of SiC, TiB2 and SiO2 transform into their amorphous forms, respectively. The formation of these relatively soft amorphous layers, which blocks the coherent growth of the multilayer films, is the main reason of hardness decline at large SiC, TiB2 and SiO2 layer thicknesses.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第6期1292-1300,共9页
Journal of Inorganic Materials
基金
国家自然科学基金(50571062)
关键词
纳米多层膜
外延生长
非晶晶化
超硬效应
nano-multilayer films
epitaxial growth
crystallization of amorphous
superhardness effect
