Low-temperature Cu-Cu bonding by self-reduction of particle-free Ag ion paste

With the assistance of Pt-catalyzed formic acid vapor, robust Ag-Cu bonding was realized at an ultra-low temperature of 160 °C under 3 MPa for 30 min via the sintering of Ag nanoparticles in situ generated from Ag2O microparticles. The Cu oxide layer at the interface after bonding can be eliminated, which improves the bond strength and electrical conductivity of the joint. A metallic bond contact between the sintered Ag and the Cu substrate is obtained without interfacial solid solution and intermetallic phases, and the shear strength is comparable to previous bonding at a higher temperature. The bonding mechanisms were figured out by comparing the bonding with and without the Pt-catalyzed formic acid vapor. This ultra-low temperature Ag-Cu bonding method may create more flexibilities in the structure design and material selection for power device integration.

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Facile Preparation of Self-Reducible Cu Nanoparticle Paste for Low Temperature Cu-Cu Bonding

JOM ◽

10.1007/s11837-019-03517-5 ◽

2019 ◽

Vol 71 (9) ◽

pp. 3076-3083 ◽

Cited By ~ 6

Author(s):

Yun Mou ◽

Jiaxin Liu ◽

Hao Cheng ◽

Yang Peng ◽

Mingxiang Chen

Keyword(s):

Low Temperature ◽

Facile Preparation ◽

Cu Nanoparticle ◽

Cu Bonding

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Low-Temperature Cu-Cu Bonding Using Silver Nanoparticles Fabricated by Physical Vapor Deposition

Journal of Electronic Materials ◽

10.1007/s11664-017-5831-z ◽

2017 ◽

Vol 47 (2) ◽

pp. 988-993 ◽

Cited By ~ 10

Author(s):

Zijian Wu ◽

Jian Cai ◽

Junqiang Wang ◽

Zhiting Geng ◽

Qian Wang

Keyword(s):

Silver Nanoparticles ◽

Low Temperature ◽

Vapor Deposition ◽

Physical Vapor Deposition ◽

Cu Bonding

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Low-temperature Cu-to-Cu bonding using silver nanoparticles stabilised by saturated dodecanoic acid

Materials Science and Engineering A ◽

10.1016/j.msea.2014.07.002 ◽

2014 ◽

Vol 613 ◽

pp. 372-378 ◽

Cited By ~ 17

Author(s):

Wen-Hua Li ◽

Pei-Syuan Lin ◽

Chen-Ni Chen ◽

Teng-Yuan Dong ◽

Chi-Hang Tsai ◽

...

Keyword(s):

Silver Nanoparticles ◽

Low Temperature ◽

Dodecanoic Acid ◽

Cu Bonding

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High-Density Large-Area-Array Interconnects Formed by Low-Temperature Cu/Sn–Cu Bonding for Three-Dimensional Integrated Circuits

IEEE Transactions on Electron Devices ◽

10.1109/ted.2012.2193404 ◽

2012 ◽

Vol 59 (7) ◽

pp. 1941-1947 ◽

Cited By ~ 19

Author(s):

M. R. Lueck ◽

J. D. Reed ◽

C. W. Gregory ◽

A. Huffman ◽

J. M. Lannon ◽

...

Keyword(s):

Low Temperature ◽

Integrated Circuits ◽

Three Dimensional ◽

High Density ◽

Large Area ◽

Area Array ◽

Cu Bonding

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Low Temperature Cu–Cu Bonding Technology in Three-Dimensional Integration: An Extensive Review

Journal of Electronic Packaging ◽

10.1115/1.4038392 ◽

2018 ◽

Vol 140 (1) ◽

Cited By ~ 15

Author(s):

Asisa Kumar Panigrahy ◽

Kuan-Neng Chen

Keyword(s):

Low Temperature ◽

Integrated Circuit ◽

Large Scale ◽

Three Dimensional ◽

3D Ic ◽

Bonding Technology ◽

Three Dimensional Integrated Circuit ◽

Low Temperature Bonding ◽

Cu Bonding

Arguably, the integrated circuit (IC) industry has received robust scientific and technological attention due to the ultra-small and extremely fast transistors since past four decades that consents to Moore's law. The introduction of new interconnect materials as well as innovative architectures has aided for large-scale miniaturization of devices, but their contributions were limited. Thus, the focus has shifted toward the development of new integration approaches that reduce the interconnect delays which has been achieved successfully by three-dimensional integrated circuit (3D IC). At this juncture, semiconductor industries utilize Cu–Cu bonding as a key technique for 3D IC integration. This review paper focuses on the key role of low temperature Cu–Cu bonding, renaissance of the low temperature bonding, and current research trends to achieve low temperature Cu–Cu bonding for 3D IC and heterogeneous integration applications.

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Cu-Cu bonding enhancement at low temperature by using carboxylic acid surface-modified Cu nanoparticles

Materials Letters ◽

10.1016/j.matlet.2018.05.037 ◽

2018 ◽

Vol 227 ◽

pp. 179-183 ◽

Cited By ~ 23

Author(s):

Yun Mou ◽

Yang Peng ◽

Yueru Zhang ◽

Hao Cheng ◽

Mingxiang Chen

Keyword(s):

Carboxylic Acid ◽

Low Temperature ◽

Cu Nanoparticles ◽

Cu Bonding ◽

Surface Modified

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The Effect of an Ag Nanofilm on Low-Temperature Cu/Ag-Ag/Cu Chip Bonding in Air

Applied Sciences ◽

10.3390/app11209444 ◽

2021 ◽

Vol 11 (20) ◽

pp. 9444

Author(s):

Yoonho Kim ◽

Seungmin Park ◽

Sarah Eunkyung Kim

Keyword(s):

Low Temperature ◽

High Performance ◽

Bonding Process ◽

Bonding Interface ◽

Fine Pitch ◽

Bonding Technology ◽

Cu Bonding ◽

Cu Oxidation ◽

Pure Cu

Low-temperature Cu-Cu bonding technology plays a key role in high-density and high-performance 3D interconnects. Despite the advantages of good electrical and thermal conductivity and the potential for fine pitch patterns, Cu bonding is vulnerable to oxidation and the high temperature of the bonding process. In this study, chip-level Cu bonding using an Ag nanofilm at 150 °C and 180 °C was studied in air, and the effect of the Ag nanofilm was investigated. A 15-nm Ag nanofilm prevented Cu oxidation prior to the Cu bonding process in air. In the bonding process, Cu diffused rapidly to the bonding interface and pure Cu-Cu bonding occurred. However, some Ag was observed at the bonding interface due to the short bonding time of 30 min in the absence of annealing. The shear strength of the Cu/Ag-Ag/Cu bonding interface was measured to be about 23.27 MPa, with some Ag remaining at the interface. This study demonstrated the good bonding quality of Cu bonding using an Ag nanofilm at 150 °C.

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