Development of new barrier materials of compound for ultra-fine copper interconnects

我们在低温下制备了Zr-B薄膜，作为一种新材料，适用于Si-ULSI金属化中极薄的Cu扩散阻挡层。复合靶溅射沉积的Zr-B薄膜主要由ZrB_2相组成，在SiO_2上为纳米晶织构，在Cu上为纤维织构。Zr-B薄膜的电阻率与衬底SiO_2或Cu有关。B/Zr的构成比几乎为2，尽管氧、氮和碳的污染物结合在膜中。在500℃退火30 min后，Zr-B薄膜的纳米晶结构稳定。我们将3 nm厚的Zr-B薄膜应用于Cu和SiO_2之间的扩散阻挡层，证实了其稳定的阻挡性能。我们可以证明，薄Zr-B膜是一个有前途的候选人薄膜应用到金属化材料的硅ULSIs。

We have prepared thin Zr-B films at low temperatures as a new material applicable to an extremely thin barrier against Cu diffusion in Si-ULSI metallization. The sputter-deposited Zr-B films from a composite target mainly consist of ZrB_2 phase with a nanocrystalline texture on SiO_2 and a fiber texture on Cu. The resistivity of the Zr-B films depends on the substrate of SiO_2 or Cu. The constituent ratio of B/Zr is almost 2, though the contaminants of oxygen, nitrogen, and carbon are incorporated in the film. The nanocrystalline structure of the Zr-B film on SiO_2 is stable due to annealing at temperatures up to 500℃ for 30 min. We applied the 3-nm thick Zr-B film to a diffusion barrier between Cu and SiO_2, and the stable barrier properties were confirmed. We can demonstrate that the thin Zr-B film is a promising candidate for thin film application to a metallization material in Si-ULSIs.