论文标题
Cu以外的互连的外延金属
Epitaxial metals for interconnects beyond Cu
论文作者
论文摘要
在C-Plane Sapphire底物上生长的CO（0001）和RU（0001）单晶薄膜的实验测量的电阻率，作为厚度的函数，使用Fuchs-Sondheimer的半经典模型进行建模。该模型拟合表明，RU的电阻率将以约20 nm的厚度延伸到CO下方。对于厚度高于20 nm的RU膜，透射电子显微镜的螺纹和错位脱位，堆叠故障和变形双胞胎。 CO膜暴露于环境空气，以及RU上SiO2，Mgo，Al2O3和CR2O3的氧化物层的沉积，降低了金属层的表面镜面。但是，对于Ru膜，在减少环境中退火恢复了表面镜面。 CO在外延沉积的RU层上的外延电化学沉积被用作示例，以证明生成线结构后端的外延互连的可行性。描述了基于紧密结合方法的电子传输模型，其中RU互连使用了一个示例。该模型允许计算用于组成大型原子集合（10^5-10^6）结构的电导率，该结构与系统大小线性缩放，还可以结合缺陷。
The experimentally measured resistivity of Co(0001) and Ru(0001) single crystal thin films, grown on c-plane sapphire substrates, as a function of thickness is modeled using the semiclassical model of Fuchs-Sondheimer. The model fits show that the resistivity of Ru would cross below that for Co at a thickness of approximately 20 nm. For Ru films with thicknesses above 20 nm, transmission electron microscopy evidences threading and misfit dislocations, stacking faults and deformation twins. Exposure of Co films to ambient air, and the deposition of oxide layers of SiO2, MgO, Al2O3 and Cr2O3 on Ru degrade the surface specularity of the metallic layer. However, for the Ru films, annealing in a reducing ambient restores the surface specularity. Epitaxial electrochemical deposition of Co on epitaxially-deposited Ru layers is used as an example to demonstrate the feasibility of generating epitaxial interconnects for back-end of line structures. An electron transport model based on a tight-binding approach is described, with Ru interconnects used an example. The model allows conductivity to be computed for structures comprising large ensembles of atoms (10^5-10^6), scales linearly with system size and can also incorporate defects.
