Three terminal âdotted-I’ interconnect structures, with vias at both ends and an additional via in the middle, were tested under various test conditions. Mortalities (failures) were found in right segments with jL value as low as 1250 A/cm, and the mortality of a dotted-I segment is dependent on the direction and magnitude of the current in the adjacent segment. Some mortalities were also found in the right segments under a test condition where no failure was expected. Cu extrusion along the delaminated Cu/Si₃N₄ interface near the central via region was believed to cause the unexpected failures. From the time-to-failure (TTF), it is possible to quantify the Cu/Si₃N₄ interfacial strength and bonding energy. Hence, the demonstrated test methodology can be used to investigate the integrity of the Cu dual damascene processes. As conventionally determined critical jL values in two-terminal via-terminated lines cannot be directly applied to interconnects with branched segments, this also serves as a good methodology to identify the critical effective jL values for immortality.
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机译：在各种测试条件下，测试了三个端子“点缀I”互连结构，两端都有通孔，中间有一个附加通孔。在正确的线段中发现死亡率（故障），jL值低至1250 A / cm，虚线I线段的死亡率取决于相邻线段中电流的方向和大小。在预期不会发生故障的测试条件下，在正确的段中也发现了一些死亡率。据认为，沿着中央通孔区域附近的分层Cu /Si₃N₄界面的Cu挤压会导致意外的故障。从失效时间（TTF），可以量化Cu /Si₃N₄的界面强度和结合能。因此，已证明的测试方法可用于研究铜双镶嵌工艺的完整性。由于传统上确定的两端通孔终止线中的临界jL值不能直接应用于具有支链段的互连，因此这也是一种确定永生的临界有效jL值的好方法。
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