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Fu Z, Chen J, Zhao P, Guo X, Xiao Q, Fu X, Wang J, Yang C, Xu J, Yang JY. Interfacial Reaction and Electromigration Failure of Cu Pillar/Ni/Sn-Ag/Cu Microbumps under Bidirectional Current Stressing. Materials (Basel) 2023; 16:1134. [PMID: 36770139 PMCID: PMC9920230 DOI: 10.3390/ma16031134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/21/2023] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
The electromigration behavior of microbumps is inevitably altered under bidirectional currents. Herein, based on a designed test system, the effect of current direction and time proportion of forward current is investigated on Cu Pillar/Ni/Sn-1.8 Ag/Cu microbumps. Under thermo-electric stressing, microbumps are found to be susceptible to complete alloying to Cu6Sn5 and Cu3Sn. As a Ni layer prevents the contact of the Cu pillar with the solder, Sn atoms mainly react with the Cu pad, and the growth of Cu3Sn is concentrated on the Cu pad sides. With direct current densities of 3.5 × 104 A/cm2 at 125 °C, the dissolution of a Ni layer on the cathode leads to a direct contact reaction between the Cu pillar and the solder, and the consumption of the Cu pillar and the Cu pad shows an obvious polarity difference. However, with a bidirectional current, there is a canceling effect of an atomic electromigration flux. With current densities of 2.5 × 104 A/cm2 at 125 °C, as the time proportion of the forward current approaches 50%, a polarity structural evolution will be hard to detect, and the influence of the chemical flux on Cu-Sn compounds will be more obvious. The mechanical properties of Cu/Sn3.0Ag0.5Cu/Cu are analyzed at 125 °C with direct and bidirectional currents of 1.0 × 104 A/cm2. Compared with high-temperature stressing, the coupled direct currents significantly reduced the mechanical strength of the interconnects, and the Cu-Sn compound layers on the cathode became the vulnerable spot. While under bidirectional currents, as the canceling effect of the electromigration flux intensifies, the interconnect shear strength gradually increases, and the fracture location is no longer concentrated on the cathode sides.
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Affiliation(s)
- Zhiwei Fu
- School of Energy and Power Engineering, Shandong University, Jinan 250100, China
- Science and Technology on Reliability Physics and Application of Electronic Component Laboratory, China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou 510610, China
| | - Jian Chen
- Science and Technology on Reliability Physics and Application of Electronic Component Laboratory, China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou 510610, China
| | - Pengfei Zhao
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China
| | - Xiaotong Guo
- Science and Technology on Reliability Physics and Application of Electronic Component Laboratory, China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou 510610, China
| | - Qingzhong Xiao
- Science and Technology on Reliability Physics and Application of Electronic Component Laboratory, China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou 510610, China
| | - Xing Fu
- Science and Technology on Reliability Physics and Application of Electronic Component Laboratory, China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou 510610, China
| | - Jian Wang
- School of Energy and Power Engineering, Shandong University, Jinan 250100, China
- Science and Technology on Reliability Physics and Application of Electronic Component Laboratory, China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou 510610, China
| | - Chao Yang
- School of Energy and Power Engineering, Shandong University, Jinan 250100, China
- Science and Technology on Reliability Physics and Application of Electronic Component Laboratory, China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou 510610, China
| | - Jile Xu
- Jiaxing Key Laboratory of Flexible Electronics Based Intelligent Sensing and Advanced Manufacturing Technology, Institute of Flexible Electronics Technology of THU, Jiaxing 314000, China
| | - Jia-Yue Yang
- School of Energy and Power Engineering, Shandong University, Jinan 250100, China
- Optics & Thermal Radiation Research Center, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao 266237, China
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Annuar S, Mahmoodian R, Hamdi M, Tu KN. Intermetallic compounds in 3D integrated circuits technology: a brief review. Sci Technol Adv Mater 2017; 18:693-703. [PMID: 29057024 PMCID: PMC5642821 DOI: 10.1080/14686996.2017.1364975] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 08/04/2017] [Accepted: 08/04/2017] [Indexed: 06/07/2023]
Abstract
The high performance and downsizing technology of three-dimensional integrated circuits (3D-ICs) for mobile consumer electronic products have gained much attention in the microelectronics industry. This has been driven by the utilization of chip stacking by through-Si-via and solder microbumps. Pb-free solder microbumps are intended to replace conventional Pb-containing solder joints due to the rising awareness of environmental preservation. The use of low-volume solder microbumps has led to crucial constraints that cause several reliability issues, including excessive intermetallic compounds (IMCs) formation and solder microbump embrittlement due to IMCs growth. This article reviews technologies related to 3D-ICs, IMCs formation mechanisms and reliability issues concerning IMCs with Pb-free solder microbumps. Finally, future outlook on the potential growth of research in this area is discussed.
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Affiliation(s)
- Syahira Annuar
- Centre for advanced manufacturing and materials processing (AMMP), Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Reza Mahmoodian
- Centre for advanced manufacturing and materials processing (AMMP), Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
- Department of Materials Science and Engineering, University of California at Los Angeles, Los Angeles, CA, USA
- Department of Research and Development, Azarin Kar IND. Co, Kerman, Iran
| | - Mohd Hamdi
- Centre for advanced manufacturing and materials processing (AMMP), Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
- Department of Materials Science and Engineering, University of California at Los Angeles, Los Angeles, CA, USA
| | - King-Ning Tu
- Department of Materials Science and Engineering, University of California at Los Angeles, Los Angeles, CA, USA
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan, People's Republic of China
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