Microstructure of amorphous tantalum nitride thin films

S. Tsukimoto, M. Moriyama, Masanori Murakami

    Research output: Contribution to journalArticlepeer-review

    60 Citations (Scopus)

    Abstract

    The main purpose of the present microstructural analysis by transmission electron microscopy (TEM) and X-ray diffraction was to investigate whether amorphous TaN films are a potential candidate as diffusion barrier for Cu wiring used in Si devices. The TaN thin films were prepared by a sputter-deposition technique using Ar and N2 mixed gas, and the film structure was found to be sensitive to the gas flow ratio of N2 vs. Ar during sputtering. Polycrystalline TaN films were obtained when the N 2/(Ar+N2) ratio was smaller than 0.10 and amorphous TaN films were obtained when the ratio was larger than 0.15. Cross-sectional TEM observations revealed that the amorphous films had columnar structure with fine grains and that nano-scaled voids segregated at the boundaries. In addition, two-layered structures were observed in the amorphous TaN films and high density of the grain boundaries was formed close to the substrate. The present results suggested that the amorphous TaN films would not have high resistance against interdiffusion between two different materials because the density of grain boundaries with small voids was extremely high.

    Original languageEnglish
    Pages (from-to)222-226
    Number of pages5
    JournalThin Solid Films
    Volume460
    Issue number1-2
    DOIs
    Publication statusPublished - 2004 Jul 22

    Keywords

    • Amorphous materials
    • Electron microscopy
    • Grain boundary
    • Tantalum nitride

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Surfaces and Interfaces
    • Surfaces, Coatings and Films
    • Metals and Alloys
    • Materials Chemistry

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