Analysis of Electromechanically-Induced Failure of Metallic Thin Films Mediated by Void Dynamics

空洞动力学介导的机电诱发金属薄膜失效分析

• 批准号: 0302226
• 负责人: Dimitrios Maroudas
• 金额: $ 20.51万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2005-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0302226&HistoricalAwards=false
• 关键词: Analysis; Electromechanically; Induced; Failure; Metallic

0201319MaroudasDevice interconnections in modern integrated circuits consist of metallic lines with cross-sections characterized by sub-micron length scales. Electromechanically-induced failure of such metallic lines is a major materials reliability problem in microelectronics. Failure is commonly mediated by the dynamics of microvoids that exist in these metallic lines. Void migration, growth, and morphological change are driven by electromigration, curvature-driven surface diffusion, and stress-induced surface diffusion, coupled with plastic flow in the strained metallic film. Fundamental understanding of such microstructural-scale dynamical phenomena and development of computational tools for their quantitative analysis are necessary for enabling engineering strategies to improve interconnect reliability. Toward this end, the proposed research addresses systematically the complex, nonlinear void dynamics in ductile metallic thin films over the range of electromechanical conditions that interconnect lines are subjected to. A number of interrelated problems will be pursued that involve single- and multiple-void dynamics, including: (i) combined effects of electromigration and mechanical stress on the migration and morphological stability of single voids, (ii) current-induced wave propagation on single void surfaces, (iii) void-void interactions that may lead to void breakup and coalescence phenomena, (iv) plastic deformation mechanisms around evolving voids, and (v) the role of plastic flow in interconnect failure. The proposed research plan emphasizes a self-consistent mesoscopic formulation of void surface evolution due to surface mass transport and plastic flow under the action of electric and stress fields, as well as systematic parametric studies to determine the onset of instabilities that may trigger failure modes. Computational implementation of the self-consistent model will be based on novel boundary-integral methods, standard finite-element methods, and recently developed methods for tracking moving interfaces. The predictive capabilities of this mesoscopic modeling will be enhanced by atomistic calculations of surface and interface properties according to many-body interatomic potentials. In addition, multi-million-atom molecular-dynamics (MD) simulations will be carried out to probe the nano-scale mechanisms that govern plastic deformation in the vicinity of voids in strained ductile metallic systems. Analysis of the MD results will provide the constitutive relations for plastic deformation required for the closure of the meso-scale problem.***

0201319 Maroudas现代集成电路中的器件互连由具有亚微米长度尺度的横截面的金属线组成。 这种金属线的机电诱导失效是微电子学中的主要材料可靠性问题。 失效通常由这些金属线中存在的微孔的动力学介导。 空穴迁移、生长和形态变化是由电迁移、曲率驱动的表面扩散和应力诱导的表面扩散以及应变金属膜中的塑性流动驱动的。 这种微观尺度的动力学现象和发展的计算工具，其定量分析的基本理解是必要的，使工程策略，以提高互连可靠性。为此，拟议的研究系统地解决了复杂的，非线性的空隙动力学在韧性金属薄膜的机电条件的范围内，互连线进行。 将探讨一些涉及单空穴和多空穴动力学的相互关联的问题，包括：（i）电迁移和机械应力对单个空隙的迁移和形态稳定性的组合效应，（ii）单个空隙表面上的电流感应波传播，（iii）可能导致空隙分裂和合并现象的空隙-空隙相互作用，（iv）围绕演化空隙的塑性变形机制，以及（v）塑性流动在互连失效中的作用。拟议的研究计划强调一个自洽的介观配方的空隙表面演变，由于表面质量传输和塑性流动的作用下的电场和应力场，以及系统的参数研究，以确定发病的不稳定性，可能会触发故障模式。 自洽模型的计算实现将基于新的边界积分方法，标准的有限元方法，以及最近开发的跟踪移动界面的方法。 这种介观模型的预测能力将得到加强，根据多体原子间作用势的表面和界面性质的原子计算。 此外，将进行数百万原子的分子动力学（MD）模拟，以探索在应变韧性金属系统中的空隙附近的塑性变形的纳米尺度机制。 MD结果的分析将提供闭合细观问题所需的塑性变形的本构关系。*