氮分压对反应溅射(Ti,Al)N薄膜微结构与力学性能的影响

Influence of N_2 Partial Pressure on Microstructure and Mechanical Properties of Reactively Sputtered (Ti,Al)N Films

采用Ti Al复合靶在不同氮分压下制备了一系列 (Ti,Al)N薄膜 ,用EDS、XRD、TEM和微力学探针表征了薄膜的沉积速率、化学成分、微结构和力学性能。结果表明 ,氮分压对 (Ti,Al)N薄膜影响显著 :合适的氮分压可以得到化学计量比的(Ti,Al)N薄膜 ,薄膜为单相组织 ,并呈现 (111)择优取向 ,最高硬度和弹性模量分别达到 34.4GPa和 392GPa ;过低的氮分压不但会造成薄膜贫氮 ,而且薄膜中的Al含量偏低 ,硬度不高 ;过高的氮分压下 ,由于存在”靶中毒”现象 ,尽管薄膜的成分无明显变化 ,但会大大降低其沉积速率 ,并使薄膜形成纳米晶或非晶态结构 ,薄膜的硬度也较低。

Different types of (Ti, Al)N films were grown in a gaseous mixture of argon and nitrogen by reactive sputtering of a Ti-Al composite target under different film growth conditions. The properties of the films were characterized with electron diffraction spectroscopy (EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that N2 partial pressure significantly affects the microstructures and mechanical properties of the film. At an optimal N2 partial pressure, single phased film with strong (111) texture and good stoichiometry can be easily grown and that the film displays some favorable mechanical properties, such as a maximum hardness of 34.4 GPa and an elastic module of 392 GPa. However, higher or lower N2 partial pressures may inversely affect the film quality. For instance, lower N2 pressure results in Al-poor films with deficiency of N and low hardness. Whereas, higher N2 pressure leads to target poisoning, reduction of deposition rate, and the growth of amorphous films with much lower hardness.