Keiji Watanabe

Fujitsu Laboratories Ltd.
  • High-rate ICP Etching for GaN Through-substrate Via of GaN-on-GaN HEMTs

    Keiji Watanabe, Fujitsu Laboratories Ltd.
    Naoya Okamoto, Fujitsu Limited and Fujitsu Laboratories Ltd.
    Naoya Okamoto, Fujitsu Laboratories Ltd.
    Atsushi Takahashi, Fujitsu Laboratories Ltd.
    Atsushi Takahashi, Fujitsu Limited
    Yuichi Minoura, Fujitsu Limited and Fujitsu Laboratories Ltd.
    Yuichi Minoura, Fujitsu Laboratories Ltd.
    Yusuke Kumazaki, Fujitsu Limited
    Yusuke Kumazaki, Fujitsu Laboratories Ltd.
    Masato Nishimori, Fujitsu Limited
    Masato Nishimori, Fujitsu Laboratories Ltd.
    Shiro Ozaki, Fujitsu Limited and Fujitsu Laboratories Ltd.
    Shiro Ozaki, Fujitsu Limited
    Kozo Makiyama, Fujitsu Limited and Fujitsu Laboratories Ltd.
    Kozo Makiyama, Fujitsu Limited
    Toshihiro Ohki, Fujitsu Limited and Fujitsu Laboratories Ltd.
    Toshihiro Ohki, Fujitsu Laboratories Ltd.
    Norikazu Nakamura, Fujitsu Limited and Fujitsu Laboratories Ltd.
    Naoki Hara, Fujitsu Laboratories Ltd.
    Naoki Hara, Fujitsu Limited
    Keiji Watanabe, Fujitsu Limited

    In this study, we have developed a technique for forming GaN through-substrate vias (TSV) using inductively coupled plasma (ICP) dry etching with a gas mixture of Cl2/BCl3. A 91 μm-deep GaN via-hole having a diameter of 80 μm was successfully formed at a high etching rate of 1.5 μm/min and a high etching selectivity of 35. We discuss pillar formation, RIE lag, loading effects and etch uniformity in high-rate ICP etching, which are critical issues related to the yield of via-hole fabrication. Finally, we investigated the effect of GaN TSVs on heat dissipation by thermal simulation.

    Download Paper
  • May 12, 2022 // 10:40am

    14.1 Promising Results of National Project by Japanese Ministry of the Environment to Develop GaN on GaN Power Devices and Prove their Usefulness in Real Systems

    Yohei Otoki, SCIOCS
    Masatomo Shibata, SCIOCS
    Tomoyoshi Mishima, Osaka University
    Hiroshi Ohta, Osaka University
    Y. Mori, Osaka University
    Keiji Watanabe, Fujitsu Laboratories Ltd.
    Naoya Okamoto, Fujitsu Laboratories Ltd.
    Masayoshi Yamamoto, Nagoya University
    Koji Shiozaki, Nagoya University
    Satoshi Tamura, Panasonic Corporation
    Masayuki Imanishi, Osaka University
    Kazunori Kidera, Panasonic Corporation
    Junichi Takino, Panasonic Corporation
    Yoshio Okayama, Panasonic Corporation
    Yoshio Honda, Nagoya University
    Hiroshi Amano, Nagoya University

    Abstract

    Download Paper