Electromigration Investigations of Al-Cu Interconnect Reliability

Al-Cu 互连可靠性的电迁移研究

• 批准号: 9975893
• 负责人: David Heskett
• 金额: $ 20.96万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-15 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9975893&HistoricalAwards=false
• 关键词: Electromigration; Investigations; Al; Cu; Interconnect

9975893HeskettWith the continual shrinking of semiconductor devices, failures due to electromigration-induced damage in metal interconnects have become a significant problem and concern. It has been known for some time that the addition of small amounts of copper in aluminum interconnects increases their resistance to electromigration. However, the exact role of this copper is not well understood. In this proposal the PIs will combine theoretical modeling with a variety of experimental techniques to examine and clarify the role of copper in the early stages of electromigration-induced damage of aluminum alloy interconnects. Furthermore the PIs will develop a reliable method for extrapolating the results of accelerated stress tests to normal operating conditions.Specific outcomes of their work will include the following:1. Development of a microscopic model of the electromigration process.2. Reevaluation of the conventional model used to extrapolate the results of accelerated stress tests. (Determination of the correct temperature dependence in "Black's Law".)3. Determination of the physical meaning of the stress-induced activation energy for copper and aluminum diffusion in Al-Cu metal lines.4. Determination of copper and aluminum-copper precipitate mobility in these systems as well as the specific role they play in blocking aluminum diffusion.5. Rutherford Backscattering measurements of the current-induced diffusion of copper in Al-Cu interconnects.6. Focused Ion Beam measurements of the role of film morphology (i.e. grain size distribution) in electromigration.These studies will directly address a real world problem in the microelectronics industry and will result in a significant advance in current understanding of metal diffusion under highly stressed conditions.***

9975893Heskett随着半导体器件的不断缩小，由于金属互连中电迁移引起的损坏而导致的故障已成为一个重大问题和关注点。 一段时间以来，人们已经知道，在铝互连中添加少量铜可以提高其抗电迁移能力。 然而，这种铜的确切作用尚不清楚。 在该提案中，PI 将把理论模型与各种实验技术相结合，以检查和阐明铜在电迁移引起的铝合金互连损伤早期阶段的作用。 此外，PI 将开发一种可靠的方法，将加速压力测试的结果外推到正常操作条件。他们工作的具体成果将包括以下内容：1．电迁移过程微观模型的开发。2．重新评估用于推断加速压力测试结果的传统模型。 （确定“布莱克定律”中正确的温度依赖性。） 3．确定了Al-Cu金属线中铜、铝扩散应力诱导活化能的物理意义。 4．测定铜和铝-铜沉淀物在这些系统中的迁移率以及它们在阻止铝扩散方面所起的具体作用。5． Al-Cu 互连中铜的电流感应扩散的卢瑟福背向散射测量。6．聚焦离子束测量薄膜形态（即晶粒尺寸分布）在电迁移中的作用。这些研究将直接解决微电子行业的现实问题，并将导致当前对高应力条件下金属扩散的理解取得重大进展。***