Name NOHIRA Hiroshi
Official Title Professor
Affiliation Electrical, Electronics and Communication Engineering, Faculty of Science and Engineering
Profile My specialty is the basic physical properties of semiconductors such as group III V materials and group IV materials, and the interface physical properties between semiconductor materials and dissimilar materials (metals and insulating materials). The main analytical method is X-ray photoelectron spectroscopy (XPS), which can evaluate the composition, chemical bond state, and electronic state of thin films. We are researching semiconductor devices by evaluating the physical properties of various materials using XPS and the bonding state of surfaces and interfaces. Recent research themes include evaluation of ferroelectric semiconductor materials such as AlScN, which are expected to be applied to non-volatile memory, elucidation of the interfacial dipole mechanism, evaluation of TiO2 and Al2O3 deposited on semiconductors by atomic layer deposition, and solar cells. We are conducting research such as evaluation of protective films and carrier transport layers, and elucidation of the initial process of SiC oxidation. I have an angle-resolved photoelectron spectrum analysis system that can evaluate the composition and chemical bond state of thin films with a depth resolution of nm or less, which I have created based on my own research so far.
Research Field(Keyword & Summary)
  1. (1) Evaluation of physical properties of surface and interface

    The purpose of my research is to realize new devices by introducing new materials. The first is the development of ferroelectric materials, which are expected to realize non-volatile memory, the evaluation of physical properties, and the elucidation of the interfacial dipole mechanism. The second is research on wide bandgap semiconductors such as diamond and SiC, which are expected to outperform Si power devices. The third is the evaluation of the carrier transport layer and passivation layer for improving the efficiency of Si-based solar cells. These studies are mainly conducted using X-ray photoelectron spectroscopy (XPS).

Representative Papers
  1. (1)Noriyuki Miyata, Kyoko Sumita, Akira Yasui, Ryousuke Sano, Reito Wada, and Hiroshi Nohira:"Electrically induced change in HfO2/1-monolayer TiO2/SiO2 metal-oxidesemiconductor stacks: capacitance–voltage and hard X-ray photoelectron spectroscopy studies", Applied Physics Express 14, 071005 (2021).
  2. (2) R. Sano, S. Konoshima, K. Sawano, H Nohira, “Effect of strain on the binding energy of Ge 2p and 3d core level”, Semiconductor Science and Technology, 34(1), (2019) 014006.
  3. (3) E. Shigesawa, R. Matsuoka, M. Fukumoto, R. Sano, K.M. Itoh, H. Nohira, K. Sawano, "Study on Al2O3/Ge interface formed by ALD directly on epitaxial Ge", Science and Technology, 33(12), (2018) 124020.
  4. (4) Masaharu Oshima, Daisuke Mori, Aki Takigawa, Akihiko Otsuki, Naoka Nagamura, Shun Konno, Yoshinobu Takahashi, Masato Kotsugi, Hiroshi Nohira,"Photoelectron Nano-spectroscopy of Reactive Ion Etching-Induced Damages to the Trench Sidewalls and Bottoms of 4H-SiC Trench-MOSFETs", e-Journal of Surface Science and Nanotechnology, Vol. 16 pp. 257-261,(2018).
  5. (5) Hitoshi Arai, Ryoma Toyoda, Ai Ishohashi, Yasuhisa Sano, Hiroshi Nohira, "Angle-Resolved Photoelectron Spectroscopy Studies of Initial Stage of Thermal Oxidation on 4H-SiC (0001) on-Axis and 4° Off-Axis Substrates", ECS Transactions, Vol.77 No.3 pp51-57, (2017).
  6. (6) Hitoshi Arai and Hiroshi Nohira, "Angle-resolved photoelectron spectroscopy study of initial stage of thermal oxidation on 4HSiC( 0001)", Japanese Journal of Applied Physics, Vol. 55, No. 4S, 04EB041 - 04EB04-5 (2016).
  7. (7) T. Kanashima, H. Nohira, M. Zenitaka, Y. Kajihara, S. Yamada, and K. Hamaya, "Effect of atomic-arrangement matching on La2O3/Ge heterostructures for epitaxial high-k-gate-stacks", Journal of Applied Physics, 118, No.22, pp. 2253021-1 225302-5 (2015).
  8. (8) H. Nohira, A. Komatsu, K. Yamashita, K. Kakushima, H. Iwai, K. Sawano, Y. Shiraki, "AR-HPES study on chemical bonding states of high-κ/high-μ gate stacks for advanced CMOS", Journal of Electron Spectroscopy and Related Phenomena, Vpl. 190, PartB, pp. 295-301, (2013).
  9. (9) Tomoyuki Suwa, Akinobu Teramoto, Yuki Kumagai, Kenichi Abe, Xiang Li, Yukihisa Nakao, Masashi Yamamoto, Hiroshi Nohira, Takayuki Muro, Toyohiko Kinoshita, Shigetoshi Sugawa, Tadahiro Ohmi, and Takeo Hattori, "Chemical Structure of Interfacial Transition Layer Formed on Si(100) and Its Dependence on Oxidation Temperature, Annealing in Forming Gas, and Difference in Oxidizing Species" Jpn. J. Appl. Phys. 52 (2013) 03130.
  10. (10) Yasuhiro Abe, Arata Komatsu, Hiroshi Nohira, Koji Nakanishi, Takashi Minemoto, Toshiaki Ohta, Hideyuki Takakura, "Interfacial layer formation at ZnO/CdS interface", Applied Surface Science Vol. 258, No. 20, pp. 8090-9093 (2012).
Award JSAP Paper Award 2014 (Jpn. J. Appl. Phys. 52 (2013) 031302)
Grant-in-Aid for Scientific Research Support: Japan Society for Promotion of Science (JSPS)
Recruitment of research assistant(s) No
Affiliated academic society (Membership type) Japan Society of Applied Physics (member)
The Electrochemical Society (member)
Materials Research Society (member)
Education Field (Undergraduate level) Semiconductor devices, semiconductor physical characteristics
Education Field (Graduate level) Advanced Nano-electronics