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Observation of filament formation process of Cu/HfO2/Pt ReRAM structure by hard x-ray photoelectron spectroscopy under bias operation

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Abstract

We have demonstrated resistance switching using polycrystalline HfO2 film with a Cu top electrode for nonvolatile memory applications and revealed the Cu diffusion into the HfO2 layer during the filament formation process. Resistive switching was clearly observed in the Cu/HfO2/Pt structure by performing a current–voltage measurement. The current step from a high-resistive state to a low-resistive state was of the order of 103–104 Ω, which provided a sufficient on/off ratio for use as a switching device. The filament formation process was investigated by employing hard x-ray photoelectron spectroscopy under bias operation. The application of a bias to the structure reduced the Cu2O state at the interface and the intensity ratio of Cu 2p3/2/Hf 3d5/2, providing evidence of Cu2O reduction and Cu diffusion into the HfO2 layer. These results also provide evidence that the resistance switching of the Cu/HfO2/Pt structure originates in a solid electrolyte (nanoionics model) containing Cu ions.

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REFERENCES

  1. R. Waser: Resistive non-volatile memory devices. Microelectron. Eng. 86, 1925 (2009).

    Article  CAS  Google Scholar 

  2. S.F. Karg, G.I. Meijer, J.G. Bednorz, C.T. Rettner, A.G. Schtorr, E.A. Joseph, C.H. Lam, M. Janousch, U. Staub, F. La Mattina, S.F. Alvarado, D. Widmer, R. Stutz, U. Drechsler, and D. Caimi: Transition-metal-oxide-based resistance-change memories. IBM J. Res. Dev. 52, 481 (2008).

    Article  CAS  Google Scholar 

  3. H. Pagnia and N. Sotnik: Bistable switching in electroformed metal–insulator–metal devices. Phys. Status Solidi A 108, 11 (1988).

    Article  Google Scholar 

  4. F.A. Chudnovskii, L.L. Odynets, A.L. Pergament, and G.B. Stefanovich: Electroforming and switching in oxides of transition metals: The role of metal–insulator transition in the switching mechanism. J. Solid State Chem. 122, 95 (1996).

    Article  CAS  Google Scholar 

  5. A. Asamitsu, Y. Tomioka, H. Kuwahara, and Y. Tokura: Current switching of resistive states in magnetoresistive manganites. Nature 388, 50 (1997).

    Article  CAS  Google Scholar 

  6. R. Fors, S.I. Khartsev, and A.M. Grishin: Giant resistance switching in metal-insulator-manganite junctions: Evidence for Mott transition. Phys. Rev. B 71, 045305 (2005).

    Article  CAS  Google Scholar 

  7. D.S. Kim, Y.H. Kim, C.E. Lee, and Y.T. Kim: Colossal electroresistance mechanism in a Au/Pr0.7Ca0.3MnO3/Pt sandwich structure: Evidence for a Mott transition. Phys. Rev. B 74, 174430 (2006).

    Article  CAS  Google Scholar 

  8. G.I. Meijer, U. Staub, M. Janousch, S.L. Johnson, B. Delley, and T. Neisius: Valence states of Cr and the insulator-to-metal transition in Cr-doped SrTiO3. Phys. Rev. B 72, 155102 (2005).

    Article  CAS  Google Scholar 

  9. R. Waser and M. Aono: Nanoionics-based resistive switching memories. Nat. Mater. 6, 833 (2007).

    Article  CAS  Google Scholar 

  10. T. Sakamoto, H. Sunamura, H. Kawaura, T. Hasegawa, T. Nakayama, and M. Aono: Nanometer-scale switches using copper sulfide. Appl. Phys. Lett. 82, 3032 (2003).

    Article  CAS  Google Scholar 

  11. N. Banno, T. Sakamoto, T. Hasegawa, K. Terabe, and M. Aono: Effect of ion diffusion on switching voltage of solid-electrolyte nanometer switch. Jpn. J. Appl. Phys. 46, 3666 (2006).

    Article  CAS  Google Scholar 

  12. K. Terabe, T. Hasegawa, T. Nakayama, and M. Aono: Quantized conductance atomic switch. Nature 433, 47 (2005).

    Article  CAS  Google Scholar 

  13. M.N. Kozicki, M. Park, and M. Mitkova: Nanoscale memory elements based on solid-state electrolytes. IEEE Trans. Nanotechnol. 4, 331 (2005).

    Article  Google Scholar 

  14. Y-M. Kim and J-S. Lee: Reproducible resistance switching characteristics of hafnium oxide-based nonvolatile memory devices. J. Appl. Phys. 104, 114115 (2008).

    Article  CAS  Google Scholar 

  15. T. Sakamoto, K. Lister, N. Banno, T. Hasegawa, K. Terabe, and M. Aono: Electronic transport in Ta2O5 resistive switch. Appl. Phys. Lett. 91, 92110 (2007).

    Article  CAS  Google Scholar 

  16. S. Lee, W-G. Kim, S-W. Rhee, and K. Yong: Resistance switching behaviors of hafnium oxide films grown by MOCVD for nonvolatile memory applications. J. Electrochem. Soc. 155, H92 (2008).

    Article  CAS  Google Scholar 

  17. J.F. Gibbons and W.E. Beadle: Switching properties of thin NiO films. Solid-State Electron. 7, 785 (1964).

    Article  CAS  Google Scholar 

  18. T. Tsuchiya, Y. Oyama, S. Miyoshi, and S. Yamaguchi: Nonstoichiometry-induced carrier modification in gapless type atomic switch device using Cu2S Mixed Conductor. Appl. Phys. Express 2, 055002 (2009).

    Article  CAS  Google Scholar 

  19. M. Haemori, T. Nagata, and T. Chikyow: Impact of Cu electrode on switching behavior in a Cu/HfO2/Pt structure and resultant Cu ion diffusion. Appl. Phys. Express 2, 061401 (2009).

    Article  CAS  Google Scholar 

  20. G.D. Wilk and R.M. Wallace: Electrical properties of hafnium silicate gate dielectrics deposited directly on silicon. Appl. Phys. Lett. 74, 2854 (1999).

    Article  CAS  Google Scholar 

  21. J. Robertson: High-dielectric constant gate oxides for metal oxide Si transistors. Rep. Prog. Phys. 69, 327 (2006).

    Article  CAS  Google Scholar 

  22. J.J. Yang, F. Miao, M.D. Pickett, D.A.A. Ohlberg, D.R. Stewart, C.N. Lau, and R.S. Williams: The mechanism of electroforming of metal oxide memristive switches. Nanotechnology 20, 215201 (2009).

    Article  CAS  Google Scholar 

  23. C. Yoshida, K. Kinoshita, T. Yamasaki, and Y. Sugiyama: Direct observation of oxygen movement during resistance switching in NiO/Pt film. Appl. Phys. Lett. 93, 042106 (2008).

    Article  CAS  Google Scholar 

  24. H. Shima, F. Takano, H. Muramatsu, M. Yamazaki, H. Akinaga, and A. Kogure: Local chemical state change in Co–O resistance random-access memory. Phys. Status Solidi RRL. 2, 99 (2008).

    Article  CAS  Google Scholar 

  25. Y. Yamashita, K. Ohmori, S. Ueda, H. Yoshikawa, T. Chikyow, and K. Kobayashi: Bias-voltage application in hard x-ray photoelectron spectroscopy for characterization of advanced materials. e-J. Surf. Sci. Nanotechnol. 8, 81 (2010).

    Article  CAS  Google Scholar 

  26. T. Nagata, M. Haemori, Y. Yamashita, Y. Iwashita, H. Yoshikawa, K. Kobayashi, and T. Chikyow: Oxygen migration at Pt/HfO2/Pt interface under bias operation. Appl. Phys. Lett. 97, 082902 (2010).

    Article  CAS  Google Scholar 

  27. T. Tsuruoka, K. Terabe, T. Hasegawa, and M. Aono: Forming and switching mechanisms of a cation-migration-based oxide resistive memory. Nanotechnology 21, 425205 (2010).

    Article  CAS  Google Scholar 

  28. S. Ueda, M. Tanaka, H. Yoshikawa, Y. Yamashita, Y. Matsushita, K. Kobayashi, Y. Katsuya, and S. Ishimaru: Present status of the NIMS contract beamline BL15XU at SPring-8. AIP Conf. Proc. 1234, 403 (2010).

    Article  CAS  Google Scholar 

  29. S. Doniach and M. Šunjić: Many-electron singularity in x-ray photoemission and x-ray line spectra from metals. J. Phys. Chem. 3, 285 (1970).

    CAS  Google Scholar 

  30. D.A. Shirley: High-resolution x-ray photoemission spectrum of the valence bands of gold. Phys. Rev. B. 5, 4709 (1972).

    Article  Google Scholar 

  31. S. Tanuma, C.J. Powell, and D.R. Penn: Calculations of electron inelastic mean free paths for 31 materials. Surf. Interface Anal. 11, 577 (1988).

    Article  CAS  Google Scholar 

  32. C.J. Powell, A. Jablonski, I.S. Tilinin, S. Tanuma, and D.R. Penne: Surface sensitivity of Auger-electron spectroscopy and x-ray photoelectron spectroscopy. J. Electron. Spectrosc. Relat. Phenom. 98, 1 (1999).

    Article  Google Scholar 

  33. S. Tanuma: Electron scattering effect on surface electron spectroscopies. J. Surf. Sci. Soc. Jpn. 27, 657 (2006).

    Article  CAS  Google Scholar 

  34. J.J. Yang, M.D. Pickett, X. Li, D.A.A. Ohlberg, D.R. Stewart, and R. S. Williams: Memoristive switching mechanism for metal/oxide/metal nanodevices. Nat. Nanotechnol. 3, 429 (2008).

    Article  CAS  Google Scholar 

  35. H. Schroeder and D.S. Jeong: Resistive switching in a Pt/TiO2/Pt thin film stack—a candidate for a non-volatile ReRAM. Microelectron. Eng. 84, 1982 (2007).

    Article  CAS  Google Scholar 

  36. S. Poulston, P.M. Parlett, P. Stone, and M. Bowker: Surface oxidation and reduction of CuO and Cu2O studied using XPS and XAES. Surf. Interface Anal. 24, 811 (1996).

    Article  CAS  Google Scholar 

  37. A. Galtayrise and J-P. Bonnelle: XPS and ISS studies on the interaction of H2S with polycrystalline Cu, Cu2O and CuO surfaces. Surf. Interface Anal. 23, 171 (1995).

    Article  Google Scholar 

  38. T.N. Rhodin Jr.: Low temperature oxidation of copper. I. Physical mechanism. J. Am. Chem. Soc. 72, 5102 (1950).

    Article  CAS  Google Scholar 

  39. J. Iijima, J-W. Lim, S-H. Hong, S. Suzuki, K. Mimura, and M. Isshiki: Native oxidation of ultra high purity Cu bulk and thin films. Appl. Surf. Sci. 253, 2825 (2006).

    Article  CAS  Google Scholar 

  40. F.J. Himpsel, F.R. McFeely, A. Taleb-Ibrahimi, J.A. Yarmoff, and G. Hollinger: Microscopic structure of the SiO2/Si interface. Phys. Rev. B: Condens. Matter 38, 6084 (1988).

    Article  CAS  Google Scholar 

  41. K. Kobayashi, M. Yabashi, Y. Takata, T. Tokushima, S. Shin, K. Tamasaku, D. Miwa, T. Ishikawa, H. Nohira, T. Hattori, Y. Sugita, O. Nakatsuka, A. Sakai, and S. Zaima: High resolution-high energy x-ray photoelectron spectroscopy using third-generation synchrotron radiation source, and its application to Si-high k insulator systems. Appl. Phys. Lett. 83, 1005 (2003).

    Article  CAS  Google Scholar 

  42. D. Barreca, A. Milanov, R.A. Fischer, A. Devi, and E. Tondello: Hafnium oxide thin film grown by ALD: An XPS study. Surf. Sci. Spectra 14, 34 (2007).

    Article  CAS  Google Scholar 

  43. Z. Paàl, M. Muhler, and R. Schlögl: Platinum black by XPS. Surf. Sci. Spectra 4, 119 (1996).

    Article  Google Scholar 

  44. M-C. Jung, H-D. Kim, M. Han, W. Jo, and D.C. Kim: X-ray photoelectron spectroscopy study of Pt-oxide thin films deposited by reactive sputtering using O2/Ar gas mixtures. Jpn. J. Appl. Phys. 38, 4872 (1999).

    Article  CAS  Google Scholar 

  45. V. Matolín, M. Cabala, I. Matolínová, M. Škoda, M. Václavů, K.C. Prince, T. Skála, T. Mori, H. Yoshikawa, Y. Yamashita, S. Ueda, and K. Kobayashi: Pt and Sn doped sputtered CeO2 electrodes for fuel cell application. Fuel Cells (Weinh.) 10, 139 (2010).

    Google Scholar 

  46. A.J. Bard and L.R. Faulkner: Electrochemical Methods. Fundamentals and Applications, 2nd ed. (John Wiley & Sons Inc, New York, 2001), pp. 808–809.

    Google Scholar 

  47. M. Yoshitake, Y-R. Aparna, and K. Yoshihara: General rule for predicting surface segregation of substrate metal on film surface. J. Vac. Sci. Technol. A 19, 1432 (2001).

    Article  CAS  Google Scholar 

  48. H. Takeuchi, D. Ha, and T-J. King: Observation of bulk HfO2 defects by spectroscopic ellipsometry. J. Vac. Sci. Technol. A 22, 1337 (2004).

    Article  CAS  Google Scholar 

  49. K. Ohmori, P. Ahmet, M. Yoshitake, T. Chikyow, K. Shiraishi, K. Yamabe, H. Watanabe, Y. Akasaka, Y. Nara, K-S. Chang, M.L. Green, and K. Yamada: Influences of annealing in reducing and oxidizing ambients on flatband voltage properties of HfO2 gate stack structures. J. Appl. Phys. 101, 084118 (2007).

    Article  CAS  Google Scholar 

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ACKNOWLEDGMENTS

We are grateful to Hiroshima Synchrotron Radiation Center (HiSOR), Hiroshima University, and the Japan Atomic Energy Agency (JAEA)/SPring-8 for the development of HX-PES at BL15XU in SPring-8. The HX-PES measurements were performed under the approval of the NIMS Beamline Station (Proposal No. 2009A 4600 and 2010B 4600). This work was supported in part by a grant-in-aid for Key Technology, “Atomic Switch Programmed Device” from Japan’s Ministry of Education, Culture, Sports, Science, and Technology.

We are also deeply grateful to many colleagues, in particular, Mr. Satoshi Ishimaru of SPring-8 Service, Mr. Tetsuya Adachi of National Institute for Materials Science (NIMS), Mr. Yutaka Iwashita, and Mr. Yuji Kiyota of Meiji University.

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Authors and Affiliations

  1. International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki, 305-0044, Japan

    Takahiro Nagata & Masamitsu Haemori

  2. International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki, 305-0044, Japan

    Yoshiyuki Yamashita

  3. NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo, 679-5148, Japan

    Yoshiyuki Yamashita

  4. NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo, 679-5148, Japan

    Hideki Yoshikawa & Keisuke Kobayashi

  5. International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki, 305-0044, Japan

    Toyohiro Chikyow

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  1. Takahiro Nagata
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Correspondence to Takahiro Nagata.

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Nagata, T., Haemori, M., Yamashita, Y. et al. Observation of filament formation process of Cu/HfO2/Pt ReRAM structure by hard x-ray photoelectron spectroscopy under bias operation. Journal of Materials Research 27, 869–878 (2012). https://doi.org/10.1557/jmr.2011.448

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