Theory of Electromigration Failure in Polycrystalline Metal Films

多晶金属薄膜的电迁移失效理论

• 批准号: 9100257
• 负责人: Richard Bradley
• 金额: $ 12万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 1994-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9100257&HistoricalAwards=false
• 关键词: Theory; Electromigration; Failure; Polycrystalline; Metal

Electromigration failure of polycrystalline aluminum interconnects is one of the primary failure mechanisms limiting the reliability of integrated circuits. In this research, Monte Carlo simulations and analytical studies will be made of a model of electromigration failure in polycrystalline metal thin films based on percolation theory. The dependence of the average film lifetime and the distributions of lifetimes on the temperature and degree of structural disorder will be investigated. An empirical distribution for the film lifetime which is commonly employed in engineering applications will be compared to the Monte Carlo results, providing a test of this distribution for much lower failure rates than is possible experimentally. A theory of the failure kinetics will be constructed which is based on recent advances in the theory of irreversible processes in random media. As time permits, these ideas will be applied to the related problem of fatigue-induced fracture in inhomogeneous brittle materials. %%% As integrated circuits become smaller and smaller, the problem of how to connect elements within these circuits, and the circuits themselves to the outside world, becomes more critical. As these connections, or interconnects, become smaller, the probability that circuit failure may occur in the interconnect increases. Thus, an understanding of the underlying mechanisms and of the probability for interconnect failure are important for predicting lifetimes of devices. This grant is using an unconventional approach to look at this difficult problem. Percolation theory looks at conducting systems such as interconnects from a general point of view. It is not as concerned about the underlying physical details as with the more global aspects of the problem. The research proposed here will use percolation theory for the first time to try to make predictions of interconnect lifetimes and determine general parameters which affect interconnect failure.

多晶铝互连线的电迁移失效是制约集成电路可靠性的主要失效机制之一。本研究基于渗流理论，对多晶金属薄膜的电迁移失效模型进行了蒙特卡罗模拟和分析研究。我们将研究薄膜的平均寿命和寿命分布与温度和结构无序度的关系。工程应用中常用的薄膜寿命的经验分布将与蒙特卡罗结果进行比较，从而在比实验可能的失效率低得多的情况下提供对该分布的测试。基于随机介质中不可逆过程理论的最新进展，将建立一个破坏动力学理论。在时间允许的情况下，这些想法将被应用于非均匀脆性材料中疲劳断裂的相关问题。随着集成电路变得越来越小，如何连接这些电路内的元件以及电路本身与外部世界的连接问题变得更加关键。随着这些连接或互连变得更小，在互连中可能发生电路故障的概率增加。因此，对基本机制和互连故障概率的了解对于预测器件的寿命是很重要的。这笔赠款正在用一种非常规的方法来看待这个难题。渗流理论从一般的角度看待诸如互连之类的导电系统。与其说它关心潜在的物理细节，不如说它关心这个问题更具全球性的方面。本文提出的研究将首次使用渗流理论来预测互连线寿命，并确定影响互连线失效的一般参数。