Oyo Buturi
Online ISSN : 2188-2290
Print ISSN : 0369-8009
Volume 89 , Issue 2
OYO-BUTURI Vol.89 No.2
Showing 1-13 articles out of 13 articles from the selected issue
Science As Art
Editors' Summary
  • Yusuke OIKE
    2020 Volume 89 Issue 2 Pages 68-74
    Published: February 10, 2020
    Released: February 10, 2020

    The evolution of CMOS image sensors (CIS) and the future prospects for a “sensing” world utilizing advanced imaging technologies promise to improve our quality of life by sensing anything, anywhere, anytime. Charge Coupled Device image sensors replaced video camera tubes, allowing the introduction of compact video cameras as consumer products. CIS now dominates the market for digital still cameras created by its predecessor and, with the advent of column-parallel ADCs and back-illuminated technologies, outperforms them. Stacked CIS's continue to enhance functionality and user experience in mobile devices. CIS imaging technologies promise to accelerate the progress of the sensing world by continuously improving sensitivity, extending detectable wavelengths, and further improving depth resolution and temporal resolution.

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  • Takayuki OHBA, Tomoji NAKAMURA
    2020 Volume 89 Issue 2 Pages 75-81
    Published: February 10, 2020
    Released: February 10, 2020

    The evolution of 3D integration technologies is reviewed. The market for the electronics and information industries has grown to more than 3000 billion USD due to both the improved performance and marketability of semiconductor devices and systems. Scaling and packaging technologies drive those industries. However, scaling is facing physical limits, and the performance of packaging technologies has saturated. Three-dimensional integration technology is expected to offer new breakthroughs for tackling these two issues. In this paper, to achieve the even higher integration and functionality that meets the market demands, the history of 3D multilevel technology developed worldwide for front-end and back-end processes is described, and our recent work on wafer level 3D integration is also introduced.

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  • Toshiyuki UENO
    2020 Volume 89 Issue 2 Pages 82-86
    Published: February 10, 2020
    Released: February 10, 2020

    One of the big problems for IoT is the power supply (battery) for wireless communication. The vibrational power generator which we developed has features that are simple and robust, with high output and high sensitivity, and is expected to perfectly solve the problem of the power source. Actually, many companies have started commercialization research for practical applications using the generator. In this paper, the following are described: the Fe-Ga alloy, which is the basis for the electrical and mechanical energy conversion, the structure of the device and the power generation principle, the output characteristics of the micro device, which substitutes for a coin cell and its practical structure. Then, the battery-free IoT realized by the generator, and the problems and future prospects for the popularization are explained.

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Our Research
  • Masashi HASEGAWA, Ken NIWA
    2020 Volume 89 Issue 2 Pages 87-91
    Published: February 10, 2020
    Released: February 10, 2020

    It was assumed that platinum-group-metals neither react with nitrogen nor form their nitrides at ambient pressure.However, ultra-high-pressure conditions of more than several dozen GPa have recently made it possible to synthesize their dinitrides by a direct nitridation. This short communication reports on new worldwide trends f of novel metal(M) nitride studies, such as MN2, M2N3, M3N4, particularly platinum-group-metal dinitrides, which can be synthesized only under ultra-high-pressures. The first section deals with an ultra-high-pressure synthesis technique using a diamond anvil cell combined with an infra-red-laser heating system. The next section describes their synthesis, phase stability, crystal structure, and physical properties. Other novel transition-metal dinitrides are also introduced briefly, particularly focusing on the growth of CrN2 single crystals, which exhibit the first and only success among novel metal dinitrides.

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  • Fumio KAWAMURA, Naoomi YAMADA
    2020 Volume 89 Issue 2 Pages 92-96
    Published: February 10, 2020
    Released: February 10, 2020

    The II-IV-N2 system semiconductors including ZnSnN2 have recently been energetically developed because these semiconductors can be considered as quasi-group-III nitrides. The II-IV-N2 semiconductors have wide element selectivity, which enables us to design novel semiconductors composed of non-toxic and earth-abundant elements. For this reason, ZnSnN2 is considered as a suitable semiconductor for a photovoltaic absorber, a photo catalyst, etc. We have clarified some structural and electrical properties of ZnSnN2.

    In this article, we summarize recent outcomes and introduce the potential for II-IV-N2 system semiconductors.

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Fundamental Lecture
Inside Out