Toyohiro Chikyo

Toyohiro Chikyow
  • Nano-Elecronics Materials Unit, MANA, NIMS
  • Waseda University-NIMS Joint Graduate Program
  • Affiliate Professor, MSE University of Washington
Nano electrics and related materials
Academic degree:
Ph.D., School of Science and Engineering, Waseda Univ. (1989)
Recent publications
See NIMS Researchers DB

Educational & Working History

2010 Managing director, Nano-Electronics Materials Unit
2006 Managing director, Advanced Electric Materials Center
2003 Director, Nano Materials Assembly Group,NIMS
2001 Senior researcher, National Institute for Materials Science (NIMS; reorganized from NRIM)
1994 Senior researcher, NIRIM
1993 - 1994 Visiting Researcher , North Carolina State University
1989 Researcher, National Research Institute for Metal (NRIM)
1989 Doctor of Engineering, Waseda Univeristy

Research History

Prof. Toyohiro Chiyo has been developing combinatorial synthesis systems and high throughput characterization tools to screen the candidate materials in a short time.

Based on this cutting edge technology for materials screening, he currently investigates gate stack materials including metal gate and higher-k dielectric for future nano device, where he is aiming at a direct high-k oxides on Si and work function tunable amorphous metal gate. He has also applied this combinatorial synthesis technique to memory device such as ReRAM or atomic switching device and, new transparent conductive oxide.

He has been organizing research network and collaboration scheme with industries and universities. One of the example was "high-k net" which started in 2003 to accelerate materials research in nano CMOS device with a research consortium " Selete" and several Universities. He also contributed to organize a workshop on combinatorial materials science and technology in the past 10 years and is recognized as one of the major researcher on this field.

As outreach activities, he has been working together with industries and related organization to dedicate himself to practical applications.

Selected Papers

  1. Interface chemistry and electronic structure of GaN/MgAl2O4 revealed by angle-resolved photoemission spectroscopy
    G. He, T. Chikyow, and S. F. Chichibu
    Appl. Phys. Lett. 97, 161907 (2010)
  2. Oxygen migration at Pt/HfO2/Pt interface under bias operation
    T. Nagata, M. Haemori, Y. Yamashita, Y. Iwashita, H. Yoshikawa, K. Kobayashi and T. Chikyow
    Applied Physics Letters, 97, 082902 (2010)
  3. Schottky barrier height behavior of Pt-Ru alloy contacts on single-crystal n-ZnO
    T. Nagata, J. Volk, M. Haemori, Y. Yamashita, H. Yoshikawa, R. Hayakawa, M. Yoshitake, S. Ueda, K. Kobayashi and T. Chikyow
    Journal of Applied Physics, 107, 103714 (2010)
  4. Impact of Cu electrode on switching behavior in a Cu/HfO2/Pt structure and resultant Cu ion diffusion
    M. Haemori, T. Nagata and T. Chikyow
    Applied Physics Express, 2, 061401 (2009)
  5. Capability of focused Ar ion beam sputtering method for combinatorial synthesis of metal films
    T. Nagata, M. Haemori and T. Chikyow
    Journal of Vacuum Science and Technology A, 27, 492 (2009)
  6. Pliant Epitaxial Ionic Oxides on Silicon
    D. Kukuruznyak, H. Reichert, K. Ohmori, P. Ahmet and T. Chikyow
    ADVANCED MATERIALS, 20, 3827(2008)
  7. Influences of annealing in reducing and oxidizing ambients on flatband voltage properties of HfO2 gate stack structures
    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
    J. Appl. Phys., 101, 84118 (2007)
  8. GaN Film Fabrication by Near-Atmospheric Plasma-Assisted Chemical Vapor Deposition
    T. Nagata, Y. Sakuma, T. Uehara and T. Chikyow
    Japanese Journal of Applied Physics Letter, 46, L43 (2007)
  9. First-principles studies of the intrinsic effect of nitrogen atoms on reduction in gate leakage current through Hf-based high-k dielectrics
    N. Umezawa, K. Shiraishi , T. Ohno, H. Watanabe, T. Chikyow, K. Torii, K. Yamabe, K. Yamada, H. Kitajima and T. Arikado
    Appl. Phys. Lett., 86, 143507(2005)
  10. Amorphous stability of HfO2 based ternary and binary composition spread oxide films as alternative gate dielectrics
    K. Hasegawa, P. Ahmet, N. Okazaki, T. Hasegawa, K. Fujimoto , M. Watanabe, T. Chikyow, and H. Koinuma
    Appl. Surf. Sci., 223(2004) 229-232
  11. A Combinatorial approach in oxide/semiconductor interface research for the future electron devices
    T. Chikyow, P. Ahmet, K. Nakajima, T .Koida, M .Takakura, M .Yoshimoto, and H. Koinuma
    Appl. Surf. Sci., 189 (2002) 284