NER: Debonding and Fracture of Ultra-Thin Films

NER：超薄膜的脱粘和断裂

• 批准号: 0303927
• 负责人: John Slattery
• 金额: $ 9.95万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0303927&HistoricalAwards=false
• 关键词: NER; Debonding; Fracture; Ultra; Thin

AbstractDebonding and fracture of ultra-thin (2 to 20 nm) films deposited on substrates (such as silicon) is an important problem in the manufacture of micro-electronic components. Internal stresses are developed in the thin films during their deposition, because there is a molecular mismatch at the interface between the thin film and its substrate. These stresses can result in both debonding (separation of the thin film from the substrate) and fracture.Traditional studies of stress-deformation behavior involve large material samples. The resulting descriptions of behavior assume that the material extends to ``infinity'' (perhaps 50 nm) in all directions. But within the immediate neighborhood of a phase interface, the material is subjected to long-range intermolecular forces from the adjoining phase, and the observed material behavior is different.Proposed herein is a novel extension of continuum mechanics to the near molecular scale to treat nanoscale fracturing and debonding phenomena. This theory employs known bulk material behavior outside an interfacial region and corrects this bulk material description within the interfacial region through the introduction of a body force (mutual force) that accounts for the difference in intermolecular forces when a portion of the material is replaced by an adjoinging phase. It is conjectured that this theory can provide a means to incorporate nanoscale modeling at a crack tip into macroscale fracture problems in order to predict fracture initiation and propagation from first priciples without (or with minimal) empirical parameter fitting.

摘要沉积在基底（如硅）上的超薄（2 至 20 nm）薄膜的脱粘和断裂是微电子元件制造中的一个重要问题。 由于薄膜与其基底之间的界面处存在分子失配，因此薄膜在沉积过程中会产生内应力。 这些应力会导致脱粘（薄膜与基材分离）和断裂。应力变形行为的传统研究涉及大型材料样品。 由此产生的行为描述假设材料在所有方向上延伸至“无限”（可能 50 nm）。但在相界面的紧邻范围内，材料受到来自相邻相的长程分子间力的作用，并且观察到的材料行为是不同的。本文提出了连续介质力学到近分子尺度的新扩展，以处理纳米尺度断裂和脱粘现象。该理论采用界面区域外已知的散装材料行为，并通过引入体积力（互力）来纠正界面区域内的散装材料描述，该体积力解释了当材料的一部分被替换时分子间力的差异。相邻阶段。据推测，该理论可以提供一种将裂纹尖端的纳米级建模纳入宏观断裂问题的方法，以便在没有（或最小化）经验参数拟合的情况下根据第一原理预测断裂的萌生和扩展。