Electromigration‐induced drift failure of via contacts in multilevel metallization
Electromigration‐induced drift failure of via contacts in multilevel metallization
复制标题
多层金属化中电迁移引起的通孔接触漂移失效
DOI：
10.1063/1.351615
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
S. Chittipeddi
中科院分区：
文献类型：
--
作者：
A. Oates;F. Nkansah;S. Chittipeddi
在多层金属化方案中，已经花费了大量的努力来改善通孔触点的金属侧壁复盖率，因为侧壁处的电迁移失败率可能会增加。多层导体在铝合金层下加入了耐火材料，将更好地抵抗这些空化故障。然而，这些金属化并不理想，因为在过孔的Al/耐火材料界面上，电迁移原子的通量不连续，这使得界面容易空化。本文研究了含有AlSiCu/TiN多层导体的过孔在侧壁和金属界面处的电迁移的相对重要性。我们的结果表明，空化失败与较差的金属台阶覆盖率无关，金属能级之间的界面是最容易空化的区域。金属层间空洞的形成是由于Al层偏离Al/TiN界面而形成的，并且存在一定的偏移量。
Much effort has been expended to improve metal sidewall coverage of via contacts in multilevel metallization schemes because of the possibility of an enhanced rate of electromigration failure at the sidewall. Multilayered conductors, which incorporate a refractory material beneath an Al alloy layer, will be more resistant to these voiding failures. These metallizations are not ideal, however, because of the discontinuities in the flux of electromigrating atoms at the Al/refractory interfaces of the via, which render the interfaces vulnerable to voiding. This paper examines the relative importance of electromigration at the sidewall and metal interface of vias containing AlSiCu/TiN multilayer conductors. Our results demonstrate that voiding failure is not associated with poor metal step coverage, and that the interface between the metal levels is the region most vulnerable to voiding. Formation of voids between the metal levels occurs by drift of the Al layer away from the Al/TiN interface, and there is a ...