铜工艺电迁移分模式失效机理研究

The Electromigration Bi-Modal Failure Mechanisms for Copper Processes

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。

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 interconneetion. 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 TFF （ Tome To Failure ） instead of the time-consuming PFA feedback.