Reservoirs, extensions at the cathode-end, are constructed to extend the lifetime of integrated circuit (IC) lines in terms of electromigration (EM) damage. The threshold current density j_th is the maximum current density that can be supported without causing EM damage due to the matching of the EM driving force and the back flow force, which is related to the atomic density gradient. In a previous study, we reported that reservoirs can affect j_th. In this present study, the j_th of straight Al polycrystalline lines covered with passivation was evaluated using a numerical simulation technique focusing not only on the formation of voids but also hillocks. The optimum reservoir/sink length based on ease of formation of voids and hillocks was discussed. The reservoir suppressed void formation but promoted hillock formation. Conversely, the sink suppressed hillock formation but promoted void formation. Therefore, when void and hillock formation occurred with equal case, it was considered that either no extension, or reservoir and sink of identical length were preferable for optimal threshold current density j_th. Additionally, when considering the diffusivity of atoms depending on grain boundary direction, the absence of the extension represented the optimum condition because longer reservoirs/sinks produced smaller j_th. When the ease of void and hillock formation changed, the critical atomic density of void and hillock formation shifted in response, causing the optimal extension length to change. It was found that the optimum extension length changed almost linearly based on the ease of void and hillock formation.

储液池（阴极端的延伸部分）的构造可延长电迁移（EM）损坏方面集成电路（IC）线的寿命。阈值电流密度j _th是由于与原子密度梯度有关的EM驱动力和回流力的匹配而可以在不引起EM损坏的情况下支持的最大电流密度。在先前的研究中，我们报道了储层会影响j _th。在这本研究中，Ĵ_日使用数值模拟技术评估了覆盖有钝化层的直Al多晶线的数量，该技术不仅关注空隙的形成，还关注丘陵。讨论了基于孔隙和丘陵形成容易程度的最佳储层/水槽长度。该储层抑制了孔隙的形成，但促进了小丘的形成。相反，水槽抑制了小丘的形成，但促进了空洞的形成。因此，当在相同的情况下发生空隙和小丘形成时，对于最佳阈值电流密度j _th，认为没有延伸或相同长度的储层和凹陷是优选的。另外，当考虑取决于晶界方向的原子的扩散率时，不存在延伸表示最佳条件，因为较长的储库/沉产生较小的j _th。当空隙和小丘形成的难易程度发生变化时，空隙和小丘形成的临界原子密度相应地发生移动，从而导致最佳延伸长度发生变化。发现最佳的延伸长度基于空隙和小丘形成的容易度几乎线性地变化。