Si含量对NbN/CrSiN纳米多层膜微观结构和力学性能的影响

Influence of Si content on microstructure and mechanical property of CrN/TiSiN nano-multilayered films

采用磁控溅射工艺在Si底片依次沉积NbN、CrSiN纳米层,通过改变靶材的Si含量,制备出一系列NbN/CrSiN纳米多层膜。分别采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、高透射电子显微镜(HRTEM)和纳米压痕仪研究Si含量对NbN/CrSiN纳米多层膜显微结构和力学性能的影响。实验结果表明,随着Si含量的增加,NbN相的结晶程度先增加后降低,薄膜的硬度和弹性模量也是先增高后降低,在n(Si)∶n(Nb)=3∶22时获得最高硬度和弹性模量,分别为31.92和359.3GPa。显微结构表征表明,当n(Si)∶n(Nb)=3∶22时,NbN/CrSiN纳米多层膜柱状晶生长状况最好,CrSiN层在NbN层的模板作用下转变为面心立方结构,并与NbN层呈共格外延生长。薄膜力学性能的提高主要与CrSiN与NbN形成的共格外延生长结构有关。

The NbN and CrSiN layers were alternately deposited on the Si substrates by using magnetron sputtering apparatus.A series of NbN/CrSiN nano-multilayered films with different Si contents were produced by using different Si contents.By X-ray diffractometry（XRD）,scanning electron microscopy（SEM）,high resolution transmission electron microscopy（HRTEM）and nano-indentation techniques,the influences of Si content on microstructure and mechanical properties of the NbN/CrSiN nano-multilayered films were investigated.The results indicate that with the increase of Si content,the crystallinity of the film firstly increases and then decreases,as well as the hardness and elastic modulus of the film.When the n（Si）∶n（Nb）ratio is 3∶22,the maximum hardness and elastic modulus are obtained to be 31.92 and 359.3 GPa respectively.The microstructural characterization shows that when the n（Si）∶n（Nb）ratio is 3∶22,the CrN/TiSiN nano-multilayered film presents the columnar growth feature.The CrSiN layers are fully transformed into fcc structure under the template effect and grown epitaxially with NbN layers.The improvement of the mechanical properties of the NbN/CrSiN nano-multiayered films can be attributed to the coherent and epitaxial growth between CrSiN and NbN layers.