Abstract
Five polyethylene glycol (PEG)-based compounds with varying terminal functional groups were investigated as suppressors to investigate the effect of different terminal functional groups on the ability of PEG-based suppressors to inhibit Cu pillar electroplating. The inhibition ability of the suppressors increased with increasing steric hindrance of the aromatic functional group and length of the alkyl group. PEG-based compounds bearing terminal functional groups with large steric hindrances significantly impeded the diffusion of electroplating accelerator, thus enhancing the inhibitory effect. When the molecular weight of PEG was less than 1000, possessing a terminal functional group had a greater effect on the inhibitory ability than increasing the molecular weight. The wetting ability of the electrolyte increased as the inhibitory ability of the suppressor increased. The significant steric effect of PEG p-(1,1,3,3-tetramethyl butyl)-phenyl ether was confirmed, which contributed to the convex shape of the Cu pillars and the growth of small-sized Cu grains. Conversely, the interaction between PEG and Cu electrode surface was weak. Thus, flat-top Cu pillars were obtained when PEG was used as the suppressor.
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P.C. Andricacos, C. Uzoh, J.O. Dukovic, J. Horkans, H. Deligianni, Damascene copper electroplating for chip interconnections. IBM J. Res. & Dev. 42, 567 (1998)
T. Kobayashi, J. Kawasaki, K. Mihara, H. Honma, Via-filling using electroplating for build-up PCBs. Electrochim. Acta 47, 85 (2001)
K. Kondo, T. Yonezawa, D. Mikami, T. Okubo, Y. Taguchi, K. Takahashi, D.P. Barkey, High-aspect-ratio copper-via-filling for three-dimensional chip stacking II. Reduced electrodeposition process time. J. Electrochem. Soc. 152, H173 (2005)
B.-S. Lee, S.-B. Jung, J.W. Yoon, Enhancement of Cu pillar bumps by electroless Ni plating. Microelectron. Eng. 180, 52 (2017)
L.-L. Li, C.J. Yang, Size control of copper grains by optimization of additives to achieve flat-top copper pillars through electroplating. J. Electrochem. Soc. 164, D315 (2017)
H. Honma, Plating technology for electronics packaging. Electrochim. Acta 47, 75 (2001)
Y. Shacham-Diamand, T. Osaka, M. Datta, T. Ohba, Advanced Nanoscale ULSI Interconnects: Fundamentals and Applications (Springer, Berlin, 2009).
F. Wang, K. Zhou, Q. Zhang, Y. Le, W. Liu, Y. Wang, F. Wang, Effect of molecular weight and concentration of polyethylene glycol on throughsilicon via filling by copper. Microelectron. Eng. 251, 111003 (2019)
K. Kondo, N. Yamakawa, Z. Tanaka, K. Hayashi, Copper damascene electrodeposition and additives. J. Electroanal. Chem. 559, 137 (2003)
E. Delbos, L. Omnès, A. Etcheberry, Bottom-up filling optimization for efficient TSV metallization. Microelectron. Eng. 87, 514 (2010)
W.-P. Dow, M.-Y. Yen, W.-B. Lin, S.-W. Ho, Influence of molecular weight of polyethylene glycol on microvia filling by copper electroplating. J. Electrochem. Soc. 152, C769 (2005)
C. Gabrielli, P. Mocotéguy, H. Perrot, D. Nieto-Sanz, A. Zdunek, A model for copper deposition in the damascene process. Electrochim. Acta 51, 1462 (2006)
Z. Yang, X. Wang, N. Li, Z. Wang, Design and achievement of a complete bottom-up electroless copper filling for sub-micrometer trenches. Electrochim. Acta 56, 3317 (2011)
P.M. Vereecken, R.A. Binstead, H. Deliginni, P.C. Andricacos, The chemistry of additives in damascene copper plating. IBM J. Res. Dev. 49, 3 (2005)
C. Wang, J. Zhang, P. Yang, B. Zhang, M. An, Through-hole copper electroplating using nitrotetrazolium blue chloride as a leveler. J. Electrochem. Soc. 160, D85 (2013)
W.-P. Dow, C.-W. Liu, Evaluating the filling performance of a copper plating formula using a simple galvanostat method. J. Electrochem. Soc. 153, C190 (2006)
S. Miura, H. Honma, Advanced copper electroplating for application of electronics. Surf. Coat. Technol. 91, 169–170 (2003)
K. Doblhofer, S. Wasle, D.M. Soares, K.G. Weil, G. Ertl, An EQCM study of the electrochemical copper(II)/copper(I)/copper system in the presence of PEG and chloride ions. J. Electrochem. Soc. 150, C657 (2003)
M. Hasegawa, Y. Negishi, T. Nakanishi, T. Osaka, Effects of additives on copper electrodeposition in submicrometer trenches. J. Electrochem. Soc. 152, C221 (2005)
Z.V. Feng, X. Li, A.A. Gewirth, Inhibition due to the interaction of polyethylene glycol, chloride, and copper in plating baths: a surface-enhanced Raman study. J. Phem. Chem. B 107, 9415 (2003)
M. Yokoi, S. Konishi, T. Hayashi, Adsorption behavior of polyoxyethyleneglycole on the copper surface in an acid copper sulfate bath. Denki Kagaku oyobi Kogyo Butsuri Kagaku 52, 218 (1984)
L. Zhang, Z.-Q. Liu, S.-W. Chen, Y.-D. Wang, W.-M. Long, Y.-H. Guo, S.-Q. Wang, G. Ye, W.-Y. Liu, Materials, processing and reliability of low temperature bonding in 3D chip stacking. J. Alloy. Compd. 750, 980 (2018)
L. Qiu, A. Ikeda, K. Noda, S. Nakai, T. Asano, Room-temperature Cu microjoining with ultrasonic bonding of cone-shaped bump. Jpn. J. Appl. Phys. 52, 04CB10 (2013)
A.J. Bard, L.R. Faulkner, Electrochemical Methods, Fundamentals and Applications,&Nbsp;Chapter 1, 2nd edn. (Wiley, New York, 2001).
J. Mendez, R. Akolkar, U. Landau, Polyether suppressors enabling copper metallization of high aspect ratio interconnects. J. Electrochem. Soc. 156, D474 (2009)
W. Hayes, B.W. Greenland, Supramolecular Polymer Networks and Gels, Chapter 4 (Springer, Cham, 2015).
R.J. Robson, E.A. Dennis, The size, shape, and hydration of nonionic surfactant micelles. Triton X-100. J. Phys. Chem. 81, 1075 (1977)
G. Behl, P. Kumar, M. Sikka, L. Fitzhenry, A. Chhikara, PEG-coumarin nanoaggregates as π–π stacking derived small molecule lipophile containing self-assemblies for anti-tumour drug delivery. J. Biomater. Sci. Polym. Ed. 29, 360 (2018)
M. Dong, Y. Zhang, T. Hang, M. Li, Structural effect of inhibitors on adsorption and desorption behaviors during copper electroplating for through-silicon vias. Electrochim. Acta 372, 137907 (2021)
W.-P. Dow, H.-S. Huang, M.-Y. Yen, H.-C. Huang, Influence of convection-dependent adsorption of additives on microvia filling by copper electroplating. J. Electrochem. Soc. 152, C425 (2005)
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The work was partly supported by the Ministry of Science and Technology of Taiwan under Grant No. 103-2113-M-239-001-MY2.
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Li, LL., Yeh, HC. Effect of the functional group of polyethylene glycol on the characteristics of copper pillars obtained by electroplating. J Mater Sci: Mater Electron 32, 14358–14367 (2021). https://doi.org/10.1007/s10854-021-05998-0
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DOI: https://doi.org/10.1007/s10854-021-05998-0