As the semiconductor industry turns to alternate conductors to replace Cu for future interconnect nodes, much attention has been focused on evaluating the electrical performance of Ru. The typical hexagonal close-packed (hcp) phase has been extensively studied, but relatively little attention has been paid to the face-centered cubic (fcc) phase, which has been shown to nucleate in confined structures and may be present in tight-pitch interconnects. Using techniques, we benchmark the performance of fcc Ru. We find that the phonon-limited bulk resistivity of the fcc Ru is less than half of that of hcp Ru, a feature we trace back to the stronger electron-phonon coupling elements in hcp Ru that are geometrically inherited from the modified Fermi surface shape of the fcc crystal. Despite this benefit of the fcc phase, high grain boundary scattering results in increased resistivity compared to Cu-based interconnects with similar average grain size. We find, however, that the line resistance of fcc Ru is lower than that of Cu below 21 nm line width due to the conductor volume lost to adhesion and wetting liners. In addition to studying bulk transport properties, we evaluate the performance of adhesion liners for fcc Ru. We find that it is energetically more favorable for fcc Ru to bind directly to silicon dioxide than through conventional adhesion liners such as TaN and TiN. In the case that a thin liner is necessary for the Ru deposition technique, we find that the vertical resistance penalty of a liner for fcc Ru can be up to eight times lower than that calculated for conventional liners used for Cu interconnects. Our calculations, therefore, suggest that the formation of the fcc phase of Ru may be a beneficial for advanced, low-resistance interconnects.

中文翻译：

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fcc钌在高级互连中的使用的第一性原理评估

随着半导体工业转向备用导体来代替Cu作为未来的互连节点，人们已经将许多注意力集中在评估Ru的电性能上。已经对典型的六方密堆积（hcp）相进行了广泛研究，但对面心立方（fcc）相的关注却很少，该相已显示在密闭结构中成核，并且可能以紧密间距存在互连。使用技术，我们对fcc Ru的性能进行了基准测试。我们发现fcc Ru的受声子限制的体电阻率小于hcp Ru的一半，我们可以追溯到hcp Ru中更强的电子-声子耦合元素，这些元素是从费米表面修饰的费米表面形状继承而来的。 fcc晶体。尽管有fcc阶段的好处，与具有类似平均晶粒尺寸的铜基互连相比，高晶界散射导致电阻率增加。但是，我们发现，由于导体体积因粘附力和润湿衬里而损失，fcc Ru的线电阻低于21 nm线宽以下的Cu的线电阻。除了研究散装运输性能外，我们还评估了fcc Ru的粘附衬里的性能。我们发现，与通过诸如TaN和TiN之类的传统粘合衬里相比，FCC Ru直接与二氧化硅结合在能量上更有利。在Ru沉积技术需要薄衬里的情况下，我们发现fcc Ru衬里的垂直电阻损失可以比用于Cu互连的常规衬里计算的垂直电阻损失低八倍。因此，我们的计算