基于稳定固溶体团簇模型的含氮铜合金薄膜

Nitrogenous Copper Alloy Thin Films Based on Stable Solid Solution Cluster Model

目的制备结构和性能稳定的含氮铜合金薄膜,提高铜合金的硬度。方法基于稳定固溶体团簇模型在Cu-Ni基合金成分设计方面的研究,进一步利用Nb与N相对较大的负混合焓以及Ni的作用,将N带入Cu中,达到稳定N的目的。采用磁控溅射方法在N2/Ar比为1/30的气氛中制备了Si(100)基Cu-Ni-Nb-N四元合金薄膜和参比样品,并通过电子探针、X射线衍射仪和透射电子显微镜分别分析了薄膜的成分、结构和膜-基界面,采用双电测四探针测量仪和超轻微载荷努氏硬度计测量了薄膜的电阻率和硬度。结果与Cu(N)薄膜相比,四元合金薄膜具有更好的结构稳定性和更高的硬度。溅射态时,四元薄膜由铜的纳米柱状晶和少量NbN组成,硬度均在5 GPa左右。550℃/1 h退火后,薄膜致密度好,部分N能以NbN化合物的形式稳定存在于薄膜中,大部分薄膜的硬度在3 GPa以上,并且具有较好的导电性。结论采用稳定固溶体团簇模型选择固氮元素,能够制备出综合性能较好的含氮铜合金薄膜,为其进一步用于铜及其合金的表面改性奠定了基础。

In order to prepare nitrogen-containing copper alloy films with stable structure and performance, and then improve the hardness of copper alloys, the relatively large negative mixing enthalpy between Nb and N and the effect of Ni were utilized to bring N into Cu to achieve the purpose of stable existence of N, which based on previous research of the stable solid solution cluster model in the composition design of Cu-Ni-based copper alloys. Cu-Ni-Nb-N quaternary alloy thin films and reference samples were prepared by magnetron sputtering on Si(100) substrates in an atmosphere where the N2/Ar ratio was 1/30. Then the composition, structure and film-substrate interface of films were analyzed by EPMA, XRD and TEM, respectively, and the resistivity and hardness was measured by double-electric four-probe instrument and super-light-load Nodule hardness tester. Compared with Cu(N) films, quaternary alloy films exhibit better structural stability and higher hardness. The as-deposited quaternary thin films are composed of nanoscale columnar crystals of copper and a small amount of NbN, and their hardness values are about 5 GPa. After annealing at 550 ℃ for 1 h, the films show good densification, part of N can exist stably in the form of NbN compound, the hardness of most of the films is above 3 GPa, simultaneously, these films exhibit good conductivity. Therefore, the stable solid solution cluster model can be used to select the nitrogen fixation elements, and the nitrogen-containing copper alloy films with good comprehensive performance can be prepared, which lays a foundation for their further application in the surface modification of copper and its alloys.