采用纳秒准分子激光在单晶硅试样表面制备了调制周期为50nm、调制比为2的TiN/AlN多层复合膜,并研究了N2分压对多层膜微结构和硬度的影响。结果表明,在低N2分压下薄膜表面颗粒相对较小,颗粒之间的空隙也不明显;随着N2分压的升高,薄膜表面颗粒明显粗化,且直径变大高度增高,颗粒之间孔隙变大。X射线衍射(XRD)研究表明,N2分压的增大可以在一定程度上促进AlN(002)相的形成,但抑制了TiN(111)的形成。X射线光电子能谱(XPS)研究显示,薄膜中N、Al、Ti元素有多种键合形式存在,并在界面形成TixAl1-x N复合。纳米硬度测量发现,N2分压的增大有利于薄膜硬度的提高,且薄膜硬度明显依赖于晶粒的尺寸分布和相结构。这一结果说明,纳秒准分子激光沉积制备TiN/AlN的过程中,通过控制№分压调控激光等离子羽中粒子的运输能量不仅得到了预期的多层复合相结构,同时也调控了晶粒的尺寸分布。
In this study,polycrystalline TiN/AlN multi-layer composite films in various N2 partial pressures were deposited onto silicon substrate using the novel target by pulsed laser ablation. The results show that the microstructure, the grain size and the nanoindentation hardness of TiN/AlN multilayer films strongly depend on the N2 partial pressure. As the 5/2 partial pressure increasing, the energy of deposited particles and the mobility of the impinging particles are increased,which leads to the changes of orientation and surface morphology of the films. This point is also certified by XRD and XPS. Nanoinden- tation finds that the higher N2 partial pressure there is in the vacuum, the larger grain size there is in the film,and the better film hardness will be. These results indicate that it is possible to fabricate TiN/AlN multilayer films using the novel target produced by laser ablation. The morphology and size distribution of grain and phase can be controlled by N2 partial pressure. Also, the hardness depends on the size and chemical state of TiN and A1N in the multi-laver film.