铝互连线的电迁移问题及超深亚微米技术下的挑战

Electromigration in Al interconnects and the challenges in ultra-deep submicron technology

铝互连线的电迁移问题历来是微电子产业的研究热点,其面临的电迁移可靠性挑战也是芯片制造业最持久和最重要的挑战之一.从20世纪90年代开始,超深亚微米(特征尺寸≤0·18μm)铝互连技术面临了更加复杂的电迁移可靠性问题.从电迁移理论出发,分析概括了铝互连电迁移问题的研究方法,总结了上世纪至今关于铝互连电迁移问题的主要经验;最后结合已知的结论和目前芯片制造业现状,分析了当前超深亚微米铝互连线电迁移可靠性挑战的原因和表现形式,提出了解决这些问题的总方向.

Electromigration （EM） problem in Al interconnects is one of the most persistent and important challenges in the microelectronic industry. From 1990s, with the scaling down and new processes introduced, ultra-deep submicron （feature size ≤0.18μm） Al interconnects involve more complicated EM issues. In this paper, we summarized the basic formulae of the EM phenomena and got the important flux divergence equations. Based on the equations, the research methods for EM problems were reviewed. The main issues and solutions during the half century of investigation for Al EM challenges were reviewed as well. Finally, the essentials and challenges of current ultra-deep submicron Al EM reliability are analyzed, and some prospective solutions were also proposed.