具有冗余设计的铜互连线电迁移可靠性评估

铜互连的电迁移可靠性与晶粒结构、几何结构、制造工艺以及介质材料等因素有着密切的关系。分别试制了末端有一定延伸的互连线冗余结构设计的样品,以及无冗余结构的互连线样品,并对样品进行了失效加速测试。测试结果显示,采用冗余结构设计的互连线失效时间更长,具有更好的抗电迁移可靠性。对冗余结构的失效模式进行了讨论,并结合互连线的制造工艺,指出采用冗余结构设计的互连线可以在有效改善互连线的电迁移特性,而且不会引入其他影响可靠性的因素,是一种有效提高铜互连电迁移可靠性的方法。

The Evaluation on Electromigration Reliability of Copper Interconnect Structures with Extension

The electromigration(EM) reliability of Cu interconnects is closely related with the grain structure, geometric structures, technology and dielectric materials. The interconnect line samples with and without extension were produced in this paper. Failure acceleration tests were carried out on the samples. The result of the tests shows the interconnect lines with extension have longer lifetime and better EM reliability. The failure mode of the structure with extension is discussed. Based on the process, it is pointed out that interconnects EM performance can be improved effectively by using the structure with extension. The factors, which affect the reliability, won't be introduced with the application of the structure with extension. Therefore, it is an effective method to improve the Cu interconnects EM reliability.