Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-10T19:33:04.411Z Has data issue: false hasContentIssue false
  • English
  • Français

Silicide formation during Mn doping of Ge/Si (001) self-assembled quantum dots

Published online by Cambridge University Press:  06 December 2013

J. Kassim ,
Christopher A. Nolph ,
Matthieu Jamet ,
Petra Reinke  and
Jerrold A. Floro
J. Kassim*
Affiliation:
Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904
Christopher A. Nolph
Affiliation:
Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904
Matthieu Jamet
Affiliation:
Institut Nanosciences et Cryogénie/SP2M, CEA-Université Joseph Fourier, F-38054 Grenoble, France
Petra Reinke
Affiliation:
Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904
Jerrold A. Floro*
Affiliation:
Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904
*
a)Address all correspondence to this author. e-mail: jaf9r@virginia.edu
Get access

Abstract

Heteroepitaxial Ge quantum dots were grown on Si (001) by molecular beam epitaxy, with a Mn co-deposition flux giving a nominal composition of Ge0.9Mn0.1. At this large Mn flux, and with growth temperatures of 450 °C required for Ge quantum dot self-assembly, extensive second phase formation occurred. Atomic force microscopy reveals that quantum dots typical for the Ge/Si (001) system still form. In addition, copious formation of both rod-like and cluster-like morphologies is observed, with many of these structures conjoined to Ge dots. Extensive transmission electron microscopy identified several coexisting intermetallic phases, all based on Mn–silicide crystal structures, albeit with varying degrees of Ge substitution. The Ge quantum dots themselves appear to have little or no Mn incorporated in them, indicating that the intermetallic particles scavenge Mn from extended surface areas. Under these growth conditions, Mn is highly mobile, with surface diffusion lengths of the order of 800 nm, with significant bulk mobility as well, resulting in surface structures that also penetrate the Si substrate. A magnetic phase transition at 220 °C does not match known behavior of the bulk silicide phases but might result from extensive ternary alloying with Ge, especially into the cubic MnSi phase.

Type
Articles
Information
Journal of Materials Research , Volume 28 , Issue 23 , 14 December 2013 , pp. 3210 - 3217
Copyright
Copyright © Materials Research Society 2013 

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

REFERENCES

Munekata, H., Ohno, H., von Molnar, S., Segmüller, A., Chang, L., and Esaki, L.: Diluted magnetic III-V semiconductors. Phys. Rev. Lett. 63, 1849 (1989).Google Scholar
Park, Y., Hanbicki, A., Erwin, S., Hellberg, C., Sullivan, J., Mattson, J., Ambrose, T., Wilson, A., Spanos, G., and Jonker, B.: A group-IV ferromagnetic semiconductor: MnxGe1-x . Science 295, 651 (2002).Google Scholar
Devillers, T., Jamet, M., Barski, A., Poydenot, V., Bayle-Guillemaud, P., Bellet-Amalric, E., Cherifi, S., and Cibert, J.: Structure and magnetism of self-organized Ge1−xMnx nanocolumns on Ge(001). Phys. Rev. B 76, 205306 (2007).Google Scholar
Bougeard, D., Ahlers, S., Trampert, A., Sircar, N., and Abstreiter, G.: Clustering in a precipitate-free GeMn magnetic semiconductor. Phys. Rev. Lett. 97, 237202 (2006).Google Scholar
Li, A., Wendelken, J., Shen, J., Feldman, L., Thompson, J., and Weitering, H.: Magnetism in MnxGe1-x semiconductors mediated by impurity band carriers. Phys. Rev. B 72, 195205 (2005).CrossRefGoogle Scholar
Zeng, C., Zhang, Z., van Benthem, K., Chisholm, M., and Weitering, H.: Optimal doping control of magnetic semiconductors via subsurfactant epitaxy. Phys. Rev. Lett. 100, 066101 (2008).CrossRefGoogle ScholarPubMed
Jamet, M., Barski, A., Devillers, T., Poydenot, V., Dujardin, R., Bayle-Guillemaud, P., Rothman, J., Bellet-Amalric, E., Marty, A., Cibert, J., Mattana, R., and Tatarenko, S.: High-Curie-temperature ferromagnetism in self-organized Ge1-xMnx nanocolumns. Nat. Mater. 5, 653 (2006).Google Scholar
Bihler, C., Jaeger, C., Vallaitis, T., Gjukic, M., Brandt, M.S., Pippel, E., Woltersdorf, J., and Gosele, U.: Structural and magnetic properties of Mn5Ge3 clusters in a dilute magnetic germanium matrix. Appl. Phys. Lett. 88, 112506 (2006).Google Scholar
Holý, V., Lechner, R.T., Ahlers, S., Horák, L., Metzger, T.H., Navarro-Quezada, A., Trampert, A., Bougeard, D., and Bauer, G.: Diffuse x-ray scattering from inclusions in ferromagnetic Ge1−xMnx layers. Phys. Rev. B 78, 144401 (2008).Google Scholar
Pinto, N., Morresi, L., Ficcadenti, M., Murri, R., D’Orazio, F., Lucari, F., Boarino, L., and Amato, G.: Magnetic and electronic transport percolation in epitaxial Ge1–xMnx films. Phys. Rev. B 72, 165203 (2005).CrossRefGoogle Scholar
Gokhale, A.B. and Abbaschian, R.: The Ge-Mn (germanium-manganese) system. Bull. Alloy Phase Diagrams 11, 460 (1990).CrossRefGoogle Scholar
Zeng, C., Erwin, S., Feldman, L., Li, A., Jin, R., Song, Y., Thompson, J., and Weitering, H.: Epitaxial ferromagnetic Mn5Ge3 on Ge(111). Appl. Phys. Lett. 83, 5002 (2003).Google Scholar
Yamada, N., Maeda, K., Usami, Y., and Ohoyama, T.: Magnetic properties of intermetallic compound Mn11Ge8 . J. Phys. Soc. Jpn. 55, 3721 (1986).Google Scholar
Imre, A., Csaba, G., Ji, L., Orlov, A., Bernstein, G.H., and Porod, W.: Majority logic gate for magnetic quantum-dot cellular automata. Science 311, 205 (2006).Google Scholar
Xiu, F., Wang, Y., Kim, J., Hong, A., Tang, J., Jacob, A., Zou, J., and Wang, K.: Electric-field-controlled ferromagnetism in high-Curie-temperature Mn0.05Ge0.95 quantum dots. Nat. Mater. 9, 337 (2010).Google Scholar
Kassim, J., Nolph, C., Jamet, M., Reinke, P., and Floro, J.: Ge1−xMnx heteroepitaxial quantum dots: Growth, morphology, and magnetism. J. Appl. Phys 113, 073910 (2013).Google Scholar
Kassim, J., Nolph, C., Jamet, M., Reinke, P., and Floro, J.: Mn solid solutions in self-assembled Ge/Si (001) quantum dot heterostructures. Appl. Phys. Lett. 101, 242407 (2012).Google Scholar
Nolph, C.: Incorporation of Mn into Ge quantum dots: Growth strategies to control structure and magnetism. Ph.D. dissertation, University of Virginia, Charlottesville, VA (2012).Google Scholar
Ye, H. and Amelinckx, S.: High-resolution electron microscopic study of manganese silicides MnSi2−x . J. Solid State Chem. 61, 8 (1986).Google Scholar
Meschel, S. and Kleppa, O.: Standard enthalpies of formation of some 3d transition metal silicides by high temperature direct synthesis calorimetry. J. Alloys Compd. 267, 128 (1998).CrossRefGoogle Scholar
Arras, E., Caliste, D., Deutsch, T., Lançon, F., and Pochet, P.: Phase diagram, structure, and magnetic properties of the Ge-Mn system: A first-principles study. Phys. Rev. B 83, 174103 (2011).CrossRefGoogle Scholar
Aoyama, I., Fedorov, M., Zaitsev, V., Solomkin, F., Eremin, I., Samunin, A., Mukoujima, M., Sano, S., and Tsuji, T.: Effects of Ge doping on micromorphology of MnSi in MnSi∼1.7 and on their thermoelectric transport properties. Jpn. J. Appl. Phys. 44, 8562 (2005).CrossRefGoogle Scholar
Takizawa, H., Sato, T., Endo, T., and Shimada, M.: High-pressure synthesis and electrical properties of Mn3Ge5 with Mn11Si19-type structure. J. Solid State Chem. 68, 234 (1987).Google Scholar
Nolph, C.A., Kassim, J.K., Floro, J.A., and Reinke, P.: Addition of Mn to Ge quantum dot surfaces—interaction with the Ge QD {105} facet and the Ge(001) wetting layer. J. Phys. Condens. Matter 25, 315801 (2013).Google Scholar
Thessieu, C., Flouquet, J., Lapertot, G., Stepanov, A.N., and Jaccard, D.: Magnetism and spin fluctuations in a weak itinerant ferromagnet: MnSi. Solid State Commun. 95, 707 (1995).CrossRefGoogle Scholar
Zhou, S., Potzger, K., Zhang, G., Mücklich, A., Eichhorn, F., Schell, N., Grötzschel, R., Schmidt, B., Skorupa, W., Helm, M., Fassbender, J., and Geiger, D.: Structural and magnetic properties of Mn-implanted Si. Phys. Rev. B 75, 085203 (2007).Google Scholar
Menshikov, A., Vokhmyanin, A., and Dorofeev, Y.: Magnetic structure and phase transformations in Mn5Si3 . Physica B 158, 319 (1990).Google Scholar
Potapova, N., Dyadkin, V., Moskvin, E., Eckerlebe, H., Menzel, D., and Grigoriev, S.: Magnetic ordering in bulk MnSi crystals with chemically induced negative pressure. Phys. Rev. B 86, 060406 (2012).Google Scholar
Zhou, A., Zhu, T., Zhao, Z., Yang, S., Dasgupta, T., Stiewe, C., Hassforf, R., and Mueller, E.: Improved thermoelectric performance of higher manganese silicides with Ge addition. J. Electron. Mater. 39, 2002–2007 (2009).Google Scholar
Vinokurova, L., Ivanov, V., Kulatov, E., and Vlasov, A.: Magnetic phase transitions and electronic structure of the manganese silicides. J. Magn. Magn. Mater. 90–91, 121 (1990).Google Scholar