|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Emerging Interconnect and Pb-free Materials for Advanced Packaging Technology
||Low-Temperature Cu-to-Cu Direct Bonding Enabled by Highly (111)-oriented and Nanotwinned Cu
||Chih Chen, Chien-Min Liu, Tien-Lin Lu, Han-wen Lin, Yi Cheng Chu, Chia-Ling Lu, Jing-Ye Juang, Kuan-Neng Chen, King-Ning Tu
|On-Site Speaker (Planned)
Low-temperature Cu-to-Cu direct bonding appears to be one of the solutions for fine-pitch microbumps for 3D IC packaging. However, the high bonding temperature and pressure are the main problems of this approach. We achieve low-temperature Cu-to-Cu direct bonding at low pressure and ordinary vacuum by highly (111)-oriented and nanotwinned Cu (nt-Cu). The bonding temperature can be lowered to 150°C at a compressive stress of 114 psi held for 60 min at 10-3 torr, or at 200°C for 30 min. Excellent bonding interface can be obtained by bonding two highly (111)-oriented nt-Cu films. Our breakthrough is based on the finding that the diffusivity of Cu atoms on (111) surfaces is approximately 3-4 orders higher than other major planes. Bonding results for patterned Cu microbumps will be also presented in the conference.
||Planned: Supplemental Proceedings volume