Ti稳定N三元Cu合金薄膜

N-Containing Ternary Cu Alloy Films Stabilized by Ti

摘要:

由于铜不能渗氮，所以普通的表面硬化方法不能用于提高铜的表面硬度。本文通过添加能够稳定N的合金元素Ti，研究含氮Cu合金薄膜的稳定性以及硬度，探索提高Cu表面硬度的有效方式。利用磁控溅射的方法将不同Ti、N含量的Cu膜溅射到单晶Si(100)基体上进行微结构、硬度以及电阻率的研究，结果表明加入Ti 确实可以使N以钛氮化合物的形式稳定存在于Cu薄膜中，且合金薄膜的硬度比纯Cu膜（~3.5 GPa）有了很大的提高，特别是Cu80.2Ti9.8N10.0薄膜即使在400℃/1h退火后硬度依然高达5.4 GPa。Ti、N含量高的Cu81.2Ti9.9N8.9薄膜的电阻率（~660 μΩ?cm）比Cu88.5Ti4.3N7.2的电阻率（~123 μΩ?cm）要高得多，但是两薄膜的硬度却相差不大，都约为5.2 GPa，由此可见，薄膜中并不是Ti、N含量越高性能越好，因此应该合理控制薄膜中的Ti、N含量。

Abstract:

Since the copper could not be nitrided, the conventional surface hardening method can not be used to improve the surface hardness of the copper. In this paper, the stability and hardness of N-containing Cu alloy films were studied by adding Ti which could stabilize N to Cu alloy films, and the effective method of improving the surface hardness of the copper was further explored. The Cu alloy films containing different content of Ti, N were deposited onto the Si (100) substrates by magnetron sputtering and their microstructure, hardness and resistivities were analyzed. The result suggests that the addition of Ti could make N exist in Cu alloys films in the form of Ti-N compounds, and the hardness of the alloy films was improved compared with that of pure Cu film (~3.5 GPa). Especially, the hardness of Cu80.2Ti9.8N10.0 film was still up to 5.4 GPa even after annealing at 400 ℃ for 1 h. The resistivity of the Cu81.2Ti9.9N8.9 film (~660 μΩ?cm) with large contents of Ti and N was much higher than that of Cu88.5Ti4.3N7.2 film (~123 μΩ?cm), but the two films were about the same hardness (~5.2 GPa). Therefore, the Ti, N contents should be controlled properly when preparing Cu(Ti, N) films.