Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-08T11:27:36.831Z Has data issue: false hasContentIssue false
  • English
  • Français

A Study of Diffusion Barrier Characteristics of Electroless Co(W,P) Layers to Lead-free SnAgCu Solder

Published online by Cambridge University Press:  31 January 2011

Hung-Chun Pan  and
Tsung-Eong Hsieh
Hung-Chun Pan
Affiliation:
[email protected], National Chiao Tung University, Department of Materials Science and Engineering, Hsinchu, Taiwan, Province of China
Tsung-Eong Hsieh
Affiliation:
[email protected], National Chiao Tung University, Department of Materials Science and Engineering, Hsinchu, Taiwan, Province of China
Get access

Abstract

Diffusion barrier characteristics of amorphous and polycrystalline electroless Co(W,P) layers (α-Co(W,P) and poly-Co(W,P)) to lead-free SnAgCu (SAC) solder were investigated via the liquid- and solid-state aging tests. In the sample containing α-Co(W,P) subjected to liquid-state aging at 250°C for 1 hr, the spallation of (Co,Cu)Sn3 intermetallic compound (IMC) into the solder and formation of a polycrystalline P-rich layer in between SAC and Co(W,P) were found. Further, the α-Co(W,P) transforms into polycrystalline structure embedded with tiny Co2P precipitates As to the sample containing α-Co(W,P) subjected to solid-state aging at 150°C up to 1000 hrs, a thick (Cu,Co)6Sn5 IMC resided in between SAC and Co(W,P) and the P-rich layer beneath IMCs was similarly seen. In the samples containing poly-Co(W,P) subjected to liquid-state aging, a mixture of (Co,Cu)Sn3 and (Co,Ag)Sn3 IMCs formed in between SAC and Co(W,P). An amorphous W-rich layer formed in between SAC and poly-Co(W,P). Similar interfacial morphology was observed in the samples subjected to the solid-state aging test. Analytical results indicated the electroless Co(W,P) is in essential a combined-type, i.e., sacrificial-type plus stuffed-type, diffusion barrier. However, the α-Co(W,P) is a better diffusion barrier for under bump metallurgy (UBM) applications in flip-chip (FC) bonding since it exhibits a lower Co consumption rate in comparison with poly-Co(W,P).

Keywords

amorphousbarrier layerdiffusion
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1156: Symposium D – Materials, Processes and Reliability for Advanced Interconnects for Micro-and Nanoelectronics–2009 , 2009 , 1156-D03-07
Copyright
Copyright © Materials Research Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Nicolet, M. A. Thin Solid Films 52, 415 (1978).Google Scholar
2 Uang, R. H. Chen, K. C. Lu, S. W. Hu, H. T. and Huang, S. H. (IEEE Electron. Packaging. Technol. Conf., Singapore, December 5-7 2000), p.292.Google Scholar
3 Liang, M.W. Hsieh, T.E. Chen, C.C. and Hung, Y.T. Jpn. J. Appl. Phys. 43, 8258 (2004).Google Scholar
4 Oppert, T., Zakel, E. and Teutsch, T. (Proc. IEMT/IMC Symp., Japan, April15-17 1998), p.106.Google Scholar
5 Teutsch, T. Oppert, T. Zakel, E. and Klusmann, E. (Electron. Comp. and Technol. Conf., Las Vegas, NV, Piscataway, NJ USA, 2000), p.107.Google Scholar
6 Mallory, G. O. and Hajdu, J. B. Electroless Plating Fundamentals and Applications, (AESF Orlando, Florida 1990) Chap. 1–7.Google Scholar
7 O'Sullivan, E. J., Schrott, A. G. Paunovic, M. Sambucetti, C. J. Marino, J. R. Bailey, P. J. Kaja, S., and Semkow, K. W. IBM J. Res. and Develop. 42, 607 (1998).Google Scholar
8 Kohn, A. Eizenberg, M. Shacham-Diamand, Y., and Sverdlov, Y. Mater. Sci. Eng. A302, 18 (2001).Google Scholar
9 Kohn, A. Eizenberg, M. Shacham-Diamand, Y., and Sverdlov, Y. Microelectron. Eng. 55, 297 (2001).Google Scholar
10 Ho, C. E. Tsai, R. Y. Lin, Y. L. and Kao, C. R. J. Elect. Mater. 31(6), 584 (2002).Google Scholar
11 Hwang, Chi-Won and Suganuma, Katsuaki, J. Mater. Res. 18(11), 2540 (2003).Google Scholar
12 Lin, Yung-Chi and Duh, Jenq-Gong, Scripta Mater. 54, 1661 (2006).Google Scholar
13 Lin, Yung-Chi and Duh, Jenq-Gong, Scripta Mater. 56, 49 (2007).Google Scholar
14 Vuorinen, V. Laurila, T. Yu, H. and Kivilahti, J. K. J. Appl. Phys. 99, 023530 (2006).Google Scholar
15 Lin, Yung-Chi, Duh, Jenq-Gong, and Chiou, Bi-Shiou, J. Elect. Mater. 35(1), 9 (2006).Google Scholar
16 Lin, Yung-Chi, Duh, Jenq-Gong, and Chiou, Bi-Shiou, J. Elect. Mater. 35(8), 1665 (2006).Google Scholar
17 Lin, Yung-Chi, Duh, Jenq-Gong, and Chiou, Bi-Shiou, J. Elect. Mater. 36 (11), 1469 (2007).Google Scholar