Simultaneous formation of n- and p-Type Ohmic contacts to 4H-SiC using the binary Ni/Al system

Kazuhiro Ito, Toshitake Onishi, Hidehisa Takeda, Susumu Tsukimoto, Mitsuru Konno, Yuya Suzuki, Masanori Murakami

    研究成果: Conference contribution

    抄録

    Fabrication procedure for silicon carbide power metal oxide semiconductor field effect transistors can be improved through simultaneous formation of ohmic contacts on both the n-source and p-well regions. We have succeeded in the simultaneous formation of Ni/Al ohmic contacts to n- and p-type SiC after annealing at 1000°C for 5 mins in an ultra-high vacuum. Ohmic contacts to n-type SiC were found when Al-layer thickness was less than about 5 nm while ohmic contacts to p-type SiC were observed for an Al-layer thickness greater than about 5 nm. Only the contacts with Al-layer thicknesses in the range of 5 to 6 nm exhibited ohmic behavior to both n- and p-type SiC, with specific contact resistances of 1.8 × 10-4 Ωcm2 and 1.2 × 102 Ωcm2 for n- and p-type SiC, respectively. An about 100 nm-thick contact layer was uniformly formed on the SiC substrate and polycrystalline δ-Ni2Si(Al) grains were formed at the contact/SiC interface. The distribution in values for the Al/Ni ratio in the δ-Ni2Si(Al) grains which exhibited ohmic behavior to both n- and p-type SiC was the largest. The smallest average δ-Ni 2Si(Al) grain size was also observed in these contacts. Thus, the large distribution in the Al/Ni ratios and a fine microstructure were found to be characteristic of the ohmic contacts to both n- and p-type SiC.

    本文言語English
    ホスト出版物のタイトルMaterials Research Society Symposium Proceedings - Silicon Carbide 2008 - Materials, Processing and Devices
    ページ189-194
    ページ数6
    出版ステータスPublished - 2008 11 17
    イベントSilicon Carbide 2008 - Materials, Processing and Devices - San Francisco, CA, United States
    継続期間: 2008 3 252008 3 27

    出版物シリーズ

    名前Materials Research Society Symposium Proceedings
    1069
    ISSN(印刷版)0272-9172

    Other

    OtherSilicon Carbide 2008 - Materials, Processing and Devices
    国/地域United States
    CitySan Francisco, CA
    Period08/3/2508/3/27

    ASJC Scopus subject areas

    • 材料科学(全般)
    • 凝縮系物理学
    • 材料力学
    • 機械工学

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