高密度三维封装TSV电迁移可靠性机理研究

项目名称： 高密度三维封装TSV电迁移可靠性机理研究

项目编号： No.61474140

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 曹立强

作者单位： 中国科学院微电子研究所

项目金额： 87万元

中文摘要： 随着CMOS工艺的不断推进和发展，晶体管数量越来越多，导致互连尺寸越来越小，信号延迟问题日趋严重，成为影响系统速度提高的关键因素。采用2.5D/3D集成的芯片堆叠技术，将有助于大大减小布线长度、缩短信号延迟，降低功耗，同时又可以缩小芯片尺寸、从而提高器件的系统性能。硅通孔（TSV）技术被认为是实现2.5D/3D芯片堆叠的关键核心技术之一。然而，该技术的真正应用仍然面临着诸多的技术挑战，电迁移可靠性问题尤为突出。本项目拟系统研究不同电流密度和环境温度条件下TSV的电迁移失效机理，评估不同TSV尺寸的电迁移失效时间（MTTF），确认电、热及应力场耦合作用下失效模式；利用同步辐射x-射线衍射技术探明原子扩散迁移引起的应力演变；借助FIB、XRD等设备检测Cu-TSV微观观组织变化，建立晶体取向与应力演变的内在联系；应用有限元分析方法进行Cu-TSV电迁移过程的仿真模拟，建立验证模型。

中文关键词： 电迁移；TSV转接板；力学性能；应力演变；微观结构

英文摘要： With the continuous development of the CMOS technology, the quantity of the transistors becomes more and more, leading to much shorter interconnecting wire and much worse signal delay, which takes the main influencing factors on the improvement of system speed. Therefore, the 2.5D/3D integrated chip stacking technology has great advantage in decreasing the wire length and signal delay, lowering the power consumption, reducing the chip size, accordingly improves the system performance of the device. TSV technoloy is considered as one of the most promising core technologies to realize the 2.5D/3D chip stacking. However, many technical challenges should be confronted before the real application. Electromigration (EM) reliability of TSV is one of the most important issues. In this project, the EM induced failure mechanism of Cu-TSV was systematicly studied with different current densities and environmental temperatures. Mean time to failure (MTTF) of EM was evaluated based on different TSV sizes, confirming the failure mode with coupling effect of electric,thermal and stress fields. Furthermore, the stress evolution induced by the atomic migration and thermal expansion was detected by synchrotron radiation x-ray technology. FIB and XRD equipments were applied to observe the microstructure of the TSV, building the internal relationship between the crystal orientation and stress evolution. Finally, FEA method was used to simulate the atomic migration process of the Cu-TSV, establishing the test model.

英文关键词： electromigration;TSV interposer;mechanical property;stress evolution;microstructure