Daisuke Nakamura

Compounds such as silicon carbide (SiC) and gallium nitride (GaN) are regarded as promising next-generation semiconductors with the potential to help process vast amounts of information under severe operating environments like autonomous driving. Unlike today’s silicon semiconductors, which are grown as crystals from molten liquid, compounds like SiC and GaN must be crystallized using gaseous materials. At the beginning, this research primarily focused on the restoration of defects occurring during crystal growth. During this phase, it was found that defects could be efficiently pushed out by the next seed crystal parallel to the direction of growth, which resulted in the identification of a new law affecting SiC bulk crystal growth. In 2004, in a joint project with Denso, we succeeded in reducing the number of defects in a single SiC crystal by a factor of between two and three. We are currently researching ways of reducing the cost of high-quality SiC while studying new growth methods for defect-free GaN crystals. We are aiming to identify effective methods of fabricating next-generation semiconductors based on an overall standpoint of quality and manufacturing costs.

Nakamura, D. and Takahashi, N., “Dispersion Stability of Inorganic Powders Harnessed to Mosaic Surface Ligands via Multifit Hansen Solubility Parameters”. Langmuir, Vol. 40 (2024), 14823-14837.
https://doi.org/10.1021/acs.langmuir.4c00641

 

Inagaki, Y., Murase, M., Tanaka, H. and Nakamura, D., “Enhancement of Mechanical Properties of High-Thermal-Conductivity Composites Comprising Boron Nitride and Poly(methyl methacrylate) Resin through Material Design Utilizing Hansen Solubility Parameters”. ACS Applied Materials & Interfaces, Vol. 16 (2024), pp. 26653-26663.
https://doi.org/10.1021/acsami.4c00626

 

Kimura, T., Shimazu, H., Kataoka, K., Itoh, K., Narita, T., Uedono, A., Tokuda, Y., Tanaka, D., Nitta, S., Amano, H. and Nakamura, D., “Impurity Reduction in Lightly Doped n-type Gallium Nitride Layer Grown via Halogen-Free Vapor-Phase Epitaxy”. Applied Physics Letters, Vol. 124 (2024), 052104.
https://doi.org/10.1063/5.0191774

 

Murase, M. and Nakamura, D., “Hansen Solubility Parameters for Directly Dealing with Surface and Interfacial Phenomena”. Langmuir, Vol. 39 (2023)., pp. 10475-10484.
https://doi.org/10.1021/acs.langmuir.3c00913

 

Nakamura, D., Iida, K., Horibuchi, K., Aoki, Y., Takahashi, N., Mori, Y., Moriyama, M., Nitta, S. and Amano, H., “Mechanism and Enhancement of Anti-parasitic-reaction Catalytic Activity of Tungsten-carbide-coated Graphite Components for the Growth of Bulk GaN Crystals”. Applied Physics Express, Vol. 15 (2022), 045501.
https://doi.org/10.35848/1882-0786/ac5ba4

 

Nakamura, D., Kimura, T., Itoh, K., Fujimoto, N., Nitta, S. and Amano, H., “Tungsten Carbide Layers Deposited on Graphite Substrates via a Wet Powder Process as Anti-parasitic-reaction Coatings for Reactor Components in GaN Growth”, CrystEngComm, Vol. 22 (2020), pp. 2632-2641.
https://doi.org/10.1039/C9CE01971E

 

Nakamura, D., Shigetoh, K. and Suzumura, A., “Tantalum Carbide Coating via Wet Powder Process: From Slurry Design to Practical Process Tests”, Journal of the European Ceramic Society, Vol. 37 (2017), pp. 1175-1185.
https://doi.org/10.1016/j.jeurceramsoc.2016.10.029

 

Nakamura, D., Kimura, T. and Horibuchi, K., “Halogen-free Vapor Phase Epitaxy for High-rate Growth of GaN Bulk Crystals”, Applied Physics Express, Vol. 10 (2017), 045504.
https://doi.org/10.7567/APEX.10.045504

 

Nakamura, D., Suzumura, A. and Shigetoh, K., “Sintered Tantalum Carbide Coatings on Graphite Substrates: Highly Reliable Protective Coatings for Bulk and Epitaxial Growth”, Applied Physics Letters, Vol. 106 (2015), 082108.
https://doi.org/10.1063/1.4913413

 

Nakamura, D., Gunjishima, I., Yamaguchi, S., Ito, T., Okamoto, A., Kondo, H., Onda, S. and Takatori, K.,“Ultrahigh-quality Silicon Carbide Single Crystals”, Nature, Vol. 430 (2004), pp. 1009-1012.
https://doi.org/10.1038/nature02810