Shearing Characteristics of Cu-Cu Joints Fabricated by Two-Step Process Using Highly -Oriented Nanotwinned Cu

被引：16

作者：

Ong, Jia-Juen ^{[1
,2
]}

Dinh-Phuc Tran ^{[1
,2
]}

Yang, Shih-Chi ^{[1
,2
]}

Shie, Kai-Cheng ^{[1
,2
]}

Chen, Chih ^{[1
,2
]}

机构：

[1] Natl Yang Ming Chiao Tung Univ, Dept Mat Sci & Engn, Hsinchu 30010, Taiwan

[2] Natl Chiao Tung Univ, Dept Mat Sci & Engn, Hsinchu 30010, Taiwan

来源：

METALS | 2021年 / 11卷 / 11期

关键词：

highly -oriented nanotwinned copper; die-to-die bonding; die-to-wafer bonding; post-annealing; grain growth; die shear test; COPPER; MICROBUMPS; STRENGTH; GROWTH;

D O I：

10.3390/met11111864

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Cu-Cu bonding has the potential to break through the extreme boundary of scaling down chips' I/Os into the sub-micrometer scale. In this study, we investigated the effect of 2-step bonding on the shear strength and electrical resistance of Cu-Cu microbumps using highly -oriented nanotwinned Cu (nt-Cu). Alignment and bonding were achieved at 10 s in the first step, and a post-annealing process was further conducted to enhance its bonding strength. Results show that bonding strength was enhanced by 2-3 times after a post-annealing step. We found 50% of ductile fractures among 4548 post-annealed microbumps in one chip, while the rate was less than 20% for the as-bonded counterparts. During the post-annealing, interfacial grain growth and recrystallization occurred, and the bonding interface was eliminated. Ductile fracture in the form of zig-zag grain boundary was found at the original bonding interface, thus resulting in an increase in bonding strength of the microbumps.

引用

页数：15

共 28 条

[1] A global assessment of adaptation investment from the perspectives of equity and efficiency [J].