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Microstructural characterization of phase-separated co-deposited Cu–Ta immiscible alloy thin films

Published online by Cambridge University Press:  26 May 2020

Max Powers ,
Benjamin Derby ,
Alex Shaw ,
Evan Raeker  and
Amit Misra
Max Powers*
Affiliation:
Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan48109, USA
Benjamin Derby
Affiliation:
Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan48109, USA
Alex Shaw
Affiliation:
Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan48109, USA
Evan Raeker
Affiliation:
Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan48109, USA
Amit Misra
Affiliation:
Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan48109, USA
*
a)Address all correspondence to this author. e-mail: maxpow@umich.edu
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Abstract

Elevated temperature co-sputtering of immiscible elements results in a variety of self-organized morphologies due to phase separation. Cu–Ta is used as a model system to understand the evolution of phase-separated microstructural morphologies by co-sputtering thin films with nominal 50–50 at.% composition at four temperatures: 25, 400, 600, and 800 °C. Scanning/transmission electron microscopy of the film cross sections showed the microstructure morphology varied from nanocrystalline Cu–Ta at 25 °C to a wavy ribbon-like structure at 400 °C, to Cu-rich agglomerates surrounded by Ta-rich veins at 600 and 800 °C. In the agglomerate-vein morphology, microstructural features were present on two length scales, from a few nanometers to a few tens of nanometers, thus making the structures hierarchical. On the nanoscale, the Cu-rich agglomerates contained Ta precipitates, whereas the Ta-rich veins had embedded Cu nanocrystals. The various microstructures can be attributed to the highly disparate constituent element interdiffusion at the deposition temperatures with the Cu having orders of magnitude higher mobility than Ta at the deposition temperatures. This study of processing–microstructure relationship will be useful in guiding the design of hierarchical multiphase microstructures in binary or multicomponent thin films with tailored mechanical properties.

Keywords

physical vapor depositionthin filmscanning transmission electron microscopy
Type
Novel Synthesis and Processing of Metals
Information
Journal of Materials Research , Volume 35 , Issue 12 , 29 June 2020 , pp. 1531 - 1542
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Copyright
Copyright © Materials Research Society 2020

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References

Avallone, J., Nizolek, T., Pollock, T., and Begley, M.: A model for high temperature deformation of nanolaminate Cu–Nb composites. Mater. Sci. Eng., A 761, 138016 (2019).CrossRefGoogle Scholar
Wu, K., Zhang, J., Li, J., Wang, Y., Liu, G., and Sun, J.: Length-scale-dependent cracking and buckling behaviors of nanostructured Cu/Cr multilayer films on compliant substrates. Acta Mater. 100, 344–358 (2015).CrossRefGoogle Scholar
Cui, Y., Derby, B., Li, N., and Misra, A.: Design of bicontinuous metallic nanocomposites for high-strength and plasticity. Mater. Des. 166, 107602 (2019).CrossRefGoogle Scholar
Vullers, F.T.N. and Spolenak, R.: From solid solutions to fully phase separated interpenetrating networks in sputter deposited “immiscible” W–Cu thin films. Acta Mater. 99, 213–227 (2015).CrossRefGoogle Scholar
Cui, Y., Li, N., and Misra, A.: An overview of interface-dominated deformation mechanisms in metallic nanocomposites elucidates using in situ straining in a TEM. J. Mater. Res. 34, 1470–1478 (2019).CrossRefGoogle Scholar
Mara, N. and Beyerlin, I.: Interface-dominant multilayers fabricated by severe plastic deformation: Stability under extreme conditions. Curr. Opin. Solid State Mater. Sci. 19, 265–276 (2015).CrossRefGoogle Scholar
Misra, A., Demkowicz, M., Zhang, X., and Hoagland, R.: The radiation damage tolerance of ultra-high strength nanolayered composites. JOM 59, 62–65 (2007).CrossRefGoogle Scholar
Wang, Y.C., Misra, A., and Hoagland, R.: Fatigue properties of nanoscale Cu/Nb multilayers. Scripta Mater. 54, 1593–1598 (2006).CrossRefGoogle Scholar
Beyerlin, I. and Wang, J.: Interface-drive mechanisms in cubic/noncubic nanolaminates at different scales. MRS Bull. 44, 31–39 (2019).CrossRefGoogle Scholar
Thornton, J.: Influence of apparatus geometry and deposition conditions on the structure and topography of thick sputtered coatings. J. Vac. Sci. Tech. 11, 666–670 (1974).CrossRefGoogle Scholar
Derby, B., Cui, Y., Baldwin, J.K., and Misra, A.: Effects of substrate temperature and deposition rate on the phase separated morphology of co-sputtered Cu–Mo thin films. Thin Solid Films 647, 50–56 (2018).CrossRefGoogle Scholar
Derby, B., Cui, Y., Baldwin, J.K., Arroyave, R., Demkowicz, M., and Misra, A.: Processing of novel psuedomorphic Cu–Mo hierarchies in thin films. Mater. Res. Lett. 7, 1–11 (2019).CrossRefGoogle Scholar
Lu, Y., Wang, C., Gao, Y., Shi, R., Liu, X., and Wang, Y.: Microstructure map for self-organized phase separation during film deposition. Phys. Rev. Lett. 109, 086101 (2012).CrossRefGoogle ScholarPubMed
Kumar, A., Derby, B., Raghavan, R., Misra, A., and Demkowicz, M.: 3-D phase-field simulations of self-organized composite morphologies in physical vapor deposited phase-separating binary alloys. J. Appl. Phys 126, 075306 (2019).Google Scholar
Holloway, K., Fryer, P., Cabral, C., Harper, J.M.E., Bailer, P.J., and Kelleher, K.H.: Tantalum as a diffusion barrier between copper and silicon: Failure mechanism and effect of nitrogen additions. J. Appl. Phys 71, 5433 (1992).CrossRefGoogle Scholar
Jain, A., Ong, S.P., Hautier, G., Chen, W., Richards, W.D., Dacek, S., Cholia, S., Gunter, D., Skinner, D., Ceder, G., and Persson, K.A.: The materials project: A materials genome approach to accelerating materials innovation. APL Mater. 1, 011002 (2013).CrossRefGoogle Scholar
Buehler, M. and Misra, A.: Mechanical behavior of nanocomposites. MRS Bull. 44, 19–24 (2019).CrossRefGoogle Scholar
Muller, C.M., Parviainen, S., Djurabekova, F., Nordlund, K., and Spolenak, R.: The as-deposited structure of co-sputtered Cu–Ta alloys, studied by X-ray diffraction and molecular dynamics simulations. Acta Mater. 82, 51–63 (2015).CrossRefGoogle Scholar
Muller, C.M., Sologubenko, A., Gerstl, S., and Spolenak, R.: On spinodal decomposition in Cu-34 at.% Ta thin films—An atom probe tomography and transmission electron microscopy study. Acta Mater. 89, 181–192 (2015).CrossRefGoogle Scholar
Kwon, K.W., Ryu, C., Sinclair, R., and Wong, S.S.: Evidence of heteroepitaxial growth of copper on beta-tantalum. Appl. Phys. Lett. 71, 3069 (1997).CrossRefGoogle Scholar
Lee, H.J., Kwon, K.W., Ryu, C., and Sinclair, R.: Thermal stability of a Cu/Ta multilayer: An intriguing interfacial reaction. Acta Mater. 47, 3965–3975 (1999).CrossRefGoogle Scholar
Jackson, M. and Li, C.: Stress relaxation and hillock growth in thin films. Acta Metall. 30, 1993–2000 (1982).CrossRefGoogle Scholar
Segmuller, A. and Murakami, M.: X-ray diffraction analysis of strains and stresses in thin films. Treatise Mater. Sci. Technol. 27, 143–200 (1988).CrossRefGoogle Scholar
Jiang, A., Tyson, T.A., Axe, L., Gladczuk, L., Sosnowski, M., and Cote, P.: The structure and stability of β-Ta thin films. Thin Solid Films 479, 166–173 (2005).CrossRefGoogle Scholar
Colin, J.J., Abadias, G., Michel, A., and Jaouen, C.: On the origin of the metastable β-Ta phase stabilization in sputtered thin films. Acta Mater. 126, 481–493 (2017).CrossRefGoogle Scholar
Read, M. and Altman, C.: A new structure in tantalum thin films. Appl. Phys. Lett. 7, 51 (1965).CrossRefGoogle Scholar
Jiang, A., Yohannan, A., Nnolim, N., Tyson, T.A., Axe, L., Lee, S., and Cote, P.: Investigation of the structure of β-Ta. Thin Solid Films 437, 116–122 (2003).CrossRefGoogle Scholar
Lee, S.L., Doxbeck, M., Mueller, J., Cipollo, M., and Cote, P.: Texture, structure, and phase transformation in sputter beta tantalum coating. Surf. Coating. Technol. 177–178, 44–51 (2004).CrossRefGoogle Scholar
Clevenger, L.A., Mutscheller, A., Harper, J.M.E., Cabral, C., and Barmak, K.: The relationship between deposition conditions, the beta to alpha phase transformation, and stress relaxation in tantalum thin films. J. Appl. Phys. 72, 4918 (1992).CrossRefGoogle Scholar
Wang, J. and Zhang, X.: Twinning effects on strength and plasticity of metallic materials. MRS Bull. 41, 274–281 (2016).CrossRefGoogle Scholar
Puthucode, A., Devaraj, A., Nag, S., Bose, S., Ayyub, P., Kaufman, M.J., and Banerjee, R.: De-vitrification of nanoscale phase-separated amorphous thin films in the immiscible copper-niobium system. Phil. Mag. 94, 1622–1641 (2014).CrossRefGoogle Scholar
Rajagopalan, M., Darling, K., Turnage, S., Koju, R.K., Hornbuckle, B., Mishin, Y., and Solanki, K.N.: Microstructural evolution in a nanocrystalline Cu–Ta alloy: A combined in situ TEM and atomistic study. Mater. Des. 113, 178–185 (2017).CrossRefGoogle Scholar
Powers, M., Derby, B., Raeker, E., Champion, N., and Misra, A.: Hillock formation in co-deposited thin films of immiscible metal alloy systems. Thin Solid Films 693, 137692 (2020).CrossRefGoogle Scholar
Nastasi, M., Saris, F.W., Hung, L.S., and Mayer, J.W.: Stability of amorphous Cu/Ta and Cu/W alloys. J. Appl. Phys. 58, 3052–3058 (1985).CrossRefGoogle Scholar
Xue, J., Li, Y., Hao, L., Gao, L., Qian, D., Song, Z., and Chen, J.: Investigation on the interfacial stability of multilayered Cu–W films at elevated deposition temperatures during co-sputtering. Vacuum 166, 162–169 (2019).CrossRefGoogle Scholar
Bonzel, H.P.: Surface diffusion tables. In Diffusion in Solid Metals and Alloys, 1st ed., Mehrer, H., ed. (Springer-Verlag, Berlin, Germany, 1990); pp. 728–744.CrossRefGoogle Scholar
Adams, C.D., Atzmon, M., Cheng, Y.T., and Srolovitz, D.J.: Phase separation during co-deposition of Al–Ge thin films. J. Mater. Res. 7, 653–666 (1991).CrossRefGoogle Scholar
Fukutani, K., Tanji, K., Saito, T., and Den, T.: Fabrication of well-aligned Al nanowire array embedded in Si matrix using limited spinodal decomposition. Jpn. J. Appl. Phys. 47, 1140–1146 (2008).CrossRefGoogle Scholar
Ohring, M.: Materials Science of Thin Films: Deposition and Structure, 2nd ed. (Academic Press, San Diego, 2002); p. 495.CrossRefGoogle Scholar
Stewart, J. and Dingreville, R.: Microstructure morphology and concentration modulation of nanocomposite thin-films during simulation physical vapor deposition. Acta Mater. 188, 181–191 (2020).CrossRefGoogle Scholar
Banerjee, R., Puthucode, A., Bose, S., and Ayyub, P.: Nanoscale phase separation in amorphous immiscible copper-niobium alloy thin films. Appl. Phys. Lett. 90, 021904 (2007).CrossRefGoogle Scholar