Browse > Article

Electroless Plating of Co-Alloy Thin Films using Alkali-Free Chemicals  

Kim, Tae Ho (Department of Chemical Engineering, Division of Energy Systems Research, Ajou University)
Yun, Hyeong Jin (Department of Chemical Engineering, Division of Energy Systems Research, Ajou University)
Kim, Chang-Koo (Department of Chemical Engineering, Division of Energy Systems Research, Ajou University)
Publication Information
Korean Chemical Engineering Research / v.45, no.6, 2007 , pp. 633-637 More about this Journal
Abstract
Electroless plating of Co-alloy thin films as capping layers for Cu interconnection has been investigated using alkali-free precursors such as $(NH_4)_2Co(SO_4)_2{\cdot}6H_2O$, $(NH_4)_2WO_4$, $(NH_4)H_2PO_4$, etc. The characteristics of the Co-alloy thin films were discussed by analyses of the effects of pH, Co-precursor concentration, and deposition temperature on the thickness and surface morphology of the films. The thickness of the Co-alloy thin films increased with increasing pH, Co-precursor concentration, and deposition temperature, similarly to the results of electroless plating of Co-alloy thin films using alkali-containing chemicals. The SEM images of the surface of the Co-alloy thin films showed that the proper ranges of pH and deposition temperature were 8.5~9.5 and $75{\sim}85^{\circ}C$, respectively. This work found a feasibility that Co-alloy thin films as capping layers for Cu interconnection could be electroless plated using alkali-free chemicals.
Keywords
Electoless Plating; Co-Alloy Thin Films; Capping Layer; Alkali-Free Chemicals;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Liu, W., Chen, W., Tsai, T., Hsieh, S. and Chang S., 'Effect of Nickel on the Initial Growth Behavior of Electroless Ni-Co-P Alloy on Silicon Substrate', Appl. Surf. Sci., 253(8), 3843-3848(2007)   DOI   ScienceOn
2 Cotton, F. A., Wilkinson, G. and Gaus, P. L., Advanced Inorganic Chemistry: A Comprehensive Text, 4th ed., John Wiley, John Wiley & Sons, Inc., New York, NY(1980)
3 Chang, S. Y., Wan, C. C., Wang, Y. Y., Shih, C. H., Tsai, M. H., Shue, S. L., Yu, C. H. and Liang, M. S., 'Characterization of Pd-Free Electroless Co-Based Cap Selectively Deposited on Cu Surface via Borane-Based Reducing Agent,' Thin Solid Films, 515(3), 1107-1111(2006)   DOI   ScienceOn
4 Gambino, J., Wynne, J., Gill, J., Mongeon, S., Meatyard, D., Lee B., Bamnolker, H., Hall, L., Li, N., Hernandez, M., Little, P., Hamed, M., Ivanov, I. and Gan, C. L., 'Self-aligned Metal Capping Layers for Copper Interconnects Using Electroless Plating,' Microelec. Eng., 83, 2059-2067(2006)   DOI   ScienceOn
5 Wolf, S. and Tauber, R. N., Silicon Processing for the VLSI Era Volume 1-Process Technology, 2nd ed., Lattice Press, Sunset Beach, CA(2000)
6 Einati, H., Bogush, V., Sverdlov, Y., Rosenberg, Y. and Shacham-Diamand Y., 'The Effect of Tungsten and Boron on the Cu Barrier and Oxidation Properties of Thin Electroless Cobalt-Tungsten-Boron Films,' Microelec. Eng., 82, 623-628(2005)   DOI   ScienceOn
7 Shacham-Diamand, Y. and Lopatin, S., 'Integrated Electroless Metallization for ULSI', Electrochim. Acta, 44(21-22), 3639-3649(1999)   DOI   ScienceOn
8 Mitchell, B. S., An Introduction to Materials Engineering and Science for Chemical and Materials Engineers, John Wiley & Sons, Inc., New York, NY(2004)
9 Shacham-Diamand, Y., Sverdlov, Y. and Petrov, N., 'Electroless Deposition of Thin-Film Cobalt-Tungsten-Phosphorus Layers Using Tungsten Phosphoric Acid for ULSI and MEMS Applications,' J. Electrochem. Soc., 148(3), C162-C167(2001)   DOI   ScienceOn
10 Wang, S. Q., 'Barriers against Copper Diffusion into Silicon and Drift through Silicon Dioxide,' MRS Bull., 19(8), 30-40(1994)
11 Sverdlov, Y. and Shacham-Diamand, Y., 'Electroless Deposition of Co(W) Thin Films,' Microelec. Eng., 70, 512-518(2003)   DOI   ScienceOn
12 Gao, W., Gong, H., He, J., Thomas, A., Chan. L. and Li, S., 'Oxidation Behavior of Cu Thin Films on Si Wafer at 175-400,' Materials Letters, 51(1), 78-84(2001)   DOI   ScienceOn
13 Antonelli, S. B., Allen, T. L., Johnson, D. C. and Dubin, V. M., 'Crystallization Behavior of Ni-P Alloy Films on Co and Cu Seed Layers,' J. Electrochem. Soc., 152(9), J120-J124(2005)   DOI   ScienceOn
14 Huang Y. and Cui F., 'Effect of Complexing Agent on the Morphology and Microstructure of Electroless Deposited Ni-P Alloy,' Surface & Coatings Technology, 201, 5416-5418(2007)   DOI   ScienceOn
15 Paunovic, M. and Schlesinger, M., Fundamentals of Electrochemical Deposition, John Wiley & Sons, Inc., New York, NY(1988)
16 Petrov, N., Sverdlov, Y. and Shacham-Diamand, Y., 'Electrochemical Study of the Electroless Deposition of CoP and CoWP Alloys,' J. Electrochem. Soc., 149(4), C187-C194(2002)