Epitaxial growth of GaN layers on ultra-thin metallic TiN buffer layers

Kazuhiro Ito, Yu Uchida, Sangjin Lee, Susumu Tsukimoto, Yuhei Ikemoto, Koji Hirata, Masanori Murakami

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    The effects of layer thickness of TiN buffer layers on GaN growth were investigated where the TiN layers with thickness of 2, 5 and 10 nm were deposited on the sapphire substrates. The 5-nm-thick TiN layers with the finest grains produced the largest GaN grains. In addition, this TiN layers provided the smoothest surface with roughness of about 10 nm in the 2-μm-thick GaN layers. Thus, the 5 nm thickness is believed to be the best thickness for the smooth GaN growth on the sapphire/TiN substrates. The reduction of the average grain size of the TiN layer is important for the smooth GaN growth. Although the grain size was reduced with decreasing the TiN layer thickness down to 5 nm, the grain size of the 2-nm-thick TiN layer was larger than that of the 5-nm-thick TiN layer. The 2-nm-thick TiN layer provided larger surface roughness of the GaN layer than the other TiN layers and a high density of graves and holes were observed on the GaN surfaces. This suggests that the 2 nm thickness was not thick enough to relax the strain introduced due to the lattice mismatch between GaN and sapphire layers.

    Original languageEnglish
    Title of host publicationGeneral Abstracts
    Subtitle of host publicationElectronic, Magnetic, and Photonic Materials Division 2007 - Proceedings of Symposium held during the 2007 TMS Annual Meeting
    Pages7-12
    Number of pages6
    Publication statusPublished - 2007 Dec 1
    Event136th TMS Annual Meeting, 2007 - Orlando, FL, United States
    Duration: 2007 Feb 252007 Mar 1

    Publication series

    NameTMS Annual Meeting

    Other

    Other136th TMS Annual Meeting, 2007
    CountryUnited States
    CityOrlando, FL
    Period07/2/2507/3/1

    Keywords

    • Epitaxial growth of GaN
    • Film thickness
    • Nucleation
    • TiN buffer layers

    ASJC Scopus subject areas

    • Condensed Matter Physics
    • Mechanics of Materials
    • Metals and Alloys

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