A Novel Lining Method for Eliminating Plastic Deformation and Protrusion of Copper in Cu-TSV Using FEM Analysis
A Novel Lining Method for Eliminating Plastic Deformation and Protrusion of Copper in Cu-TSV Using FEM Analysis
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DOI：
10.1007/s11664-020-08076-z
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发表时间：
2020-03
影响因子：
2.1
通讯作者：
Yazdan Zare;Y. Sasajima;J. Onuki
中科院分区：
文献类型：
--
作者：
Yazdan Zare;Y. Sasajima;J. Onuki
通过有限元分析，提出了一种新的内衬方法，以防止铜在经历了一个热循环(从室温加热到300℃，然后冷却到室温)后发生塑性变形和突出。使用这种技术，施加在通孔上的热应力降低到低于铜的屈服应力，防止铜发生塑性变形。因此，不仅在300℃时铜的凸出高度降低，而且在热循环结束时没有挤压凸起或盘状。与传统的钛阻挡层相比，热循环结束时铜的突出量在第一次热循环后从208.2 nm减小到3.4 nm，在连续10次热循环后从325.2 nm减小到3.4 nm。
Employing FEM analysis, a new lining method was invented to prevent plastic deformation and protrusion of copper in Cu-TSV after experiencing a thermal cycle (heating up from room temperature to 300°C and then cooling down to room temperature). Using this technique, thermal stresses exerted to the via were reduced to below the yield stress of copper, preventing copper from undergoing plastic deformation. Consequently, not only was the height of copper protrusion at 300°C decreased, but there was no extrusion bulge or dishing at the end of thermal cycle. Compared with traditional titanium barriers, copper protrusion at the end of thermal cycle decreased from 208.2 nm to 3.4 nm after the first thermal cycle and from 325.2 nm to (again) 3.4 nm after 10 successive thermal cycles.