铜工艺电迁移分模式失效机理研究

在大规模集成电路进入深次微米时代的同时,铜工艺技术也被广范应用在金属互连层的工序当中。电迁移（Electromigration,EM）测试是检测金属互连层性能的主要方法,本文针对测试结果所呈现的分模式（Bi-modal）现象,对大量累积的测试数据以及物理失效分析的结果进行分析,并且结合对铜工艺的分析,给出了失效机理的解释并以图形化的形式进行了整合归纳。提供了一种快速的通过失效时间进行失效模式分析的方法,为我们不依靠物理失效分析而快速发现工艺问题提供了可能。

The Electromigration Bi-Modal Failure Mechanisms for Copper Processes

At the deep submicron era, copper interconnections are widely used on IC manufacturing. Electromigration (EM) is one of the major indices to evaluate the performance of copper interconnection. For the EM bi-modal phenomena we observe from actual tests, we propose the corresponding failure mechanisms for the samples with different lifetimes in this paper. Combining test data, process knowledge, and PFA (Physical Failure Analysis) results, our proposed mechanisms help formulate integrated solutions on faster data analysis and lot dispositions. Our approach also leads to timely detections on process abnormality from the TTF (Tome To Failure) instead of the time-consuming PFA feedback.