Low-resistivity α-phase tungsten films grown by hot-wire assisted atomic layer deposition in high-aspect-ratio structures

Mengdi Yang (Corresponding Author), Antonius A.I. Aarnink, Jurriaan Schmitz, Alexey Y. Kovalgin

    Research output: Contribution to journalArticleAcademicpeer-review

    3 Citations (Scopus)
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    Abstract

    In this work, the so-called hot-wire (HW) assisted atomic layer deposition (HWALD) technique is employed to grow high-purity α-phase tungsten (W) films at a substrate temperature of 275 °C. The films are deposited on thermally grown silicon dioxide (SiO2) in a home-built hot-wall reactor, using alternating pulses of WF6 and HW-generated atomic hydrogen in the self-limiting surface-reaction manner characteristic for ALD. A W seed layer, needed to enable the HWALD-W process on a SiO2 surface, is formed prior to each deposition. In-situ spectroscopic ellipsometry is used to monitor the growth behavior and film properties. The films exhibit a high-purity (99 at.%) W, according to X-ray photoelectron spectroscopy. The X-ray diffraction scans reveal the existence of α-phase W. The resistivity measurements by means of four point probe, transfer length method test structures and the Drude-Lorentz SE model all reveal a low resistivity of 15 μΩ·cm. The high-resolution transmission electron microscopy analysis shows a uniform and conformal coverage of high aspect ratio structures, confirming the effective ALD process and the sufficient diffusion of both WF6 and at-H into deep trenches.
    Original languageEnglish
    Pages (from-to)199-208
    Number of pages10
    JournalThin solid films
    Volume646
    DOIs
    Publication statusPublished - 31 Jan 2018

    Fingerprint

    Tungsten
    Atomic layer deposition
    atomic layer epitaxy
    high aspect ratio
    Aspect ratio
    tungsten
    wire
    Wire
    electrical resistivity
    purity
    Spectroscopic ellipsometry
    Surface reactions
    High resolution transmission electron microscopy
    Silicon Dioxide
    surface reactions
    ellipsometry
    Seed
    seeds
    Hydrogen
    x rays

    Keywords

    • Hot wire
    • Tungsten
    • ALD
    • Alpha-phase
    • Low resistivity
    • High-aspect-ratio substrates

    Cite this

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    title = "Low-resistivity α-phase tungsten films grown by hot-wire assisted atomic layer deposition in high-aspect-ratio structures",
    abstract = "In this work, the so-called hot-wire (HW) assisted atomic layer deposition (HWALD) technique is employed to grow high-purity α-phase tungsten (W) films at a substrate temperature of 275 °C. The films are deposited on thermally grown silicon dioxide (SiO2) in a home-built hot-wall reactor, using alternating pulses of WF6 and HW-generated atomic hydrogen in the self-limiting surface-reaction manner characteristic for ALD. A W seed layer, needed to enable the HWALD-W process on a SiO2 surface, is formed prior to each deposition. In-situ spectroscopic ellipsometry is used to monitor the growth behavior and film properties. The films exhibit a high-purity (99 at.{\%}) W, according to X-ray photoelectron spectroscopy. The X-ray diffraction scans reveal the existence of α-phase W. The resistivity measurements by means of four point probe, transfer length method test structures and the Drude-Lorentz SE model all reveal a low resistivity of 15 μΩ·cm. The high-resolution transmission electron microscopy analysis shows a uniform and conformal coverage of high aspect ratio structures, confirming the effective ALD process and the sufficient diffusion of both WF6 and at-H into deep trenches.",
    keywords = "Hot wire, Tungsten, ALD, Alpha-phase, Low resistivity, High-aspect-ratio substrates",
    author = "Mengdi Yang and Aarnink, {Antonius A.I.} and Jurriaan Schmitz and Kovalgin, {Alexey Y.}",
    year = "2018",
    month = "1",
    day = "31",
    doi = "10.1016/j.tsf.2017.12.011",
    language = "English",
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    pages = "199--208",
    journal = "Thin solid films",
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    publisher = "Elsevier",

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    Low-resistivity α-phase tungsten films grown by hot-wire assisted atomic layer deposition in high-aspect-ratio structures. / Yang, Mengdi (Corresponding Author); Aarnink, Antonius A.I.; Schmitz, Jurriaan; Kovalgin, Alexey Y.

    In: Thin solid films, Vol. 646, 31.01.2018, p. 199-208.

    Research output: Contribution to journalArticleAcademicpeer-review

    TY - JOUR

    T1 - Low-resistivity α-phase tungsten films grown by hot-wire assisted atomic layer deposition in high-aspect-ratio structures

    AU - Yang, Mengdi

    AU - Aarnink, Antonius A.I.

    AU - Schmitz, Jurriaan

    AU - Kovalgin, Alexey Y.

    PY - 2018/1/31

    Y1 - 2018/1/31

    N2 - In this work, the so-called hot-wire (HW) assisted atomic layer deposition (HWALD) technique is employed to grow high-purity α-phase tungsten (W) films at a substrate temperature of 275 °C. The films are deposited on thermally grown silicon dioxide (SiO2) in a home-built hot-wall reactor, using alternating pulses of WF6 and HW-generated atomic hydrogen in the self-limiting surface-reaction manner characteristic for ALD. A W seed layer, needed to enable the HWALD-W process on a SiO2 surface, is formed prior to each deposition. In-situ spectroscopic ellipsometry is used to monitor the growth behavior and film properties. The films exhibit a high-purity (99 at.%) W, according to X-ray photoelectron spectroscopy. The X-ray diffraction scans reveal the existence of α-phase W. The resistivity measurements by means of four point probe, transfer length method test structures and the Drude-Lorentz SE model all reveal a low resistivity of 15 μΩ·cm. The high-resolution transmission electron microscopy analysis shows a uniform and conformal coverage of high aspect ratio structures, confirming the effective ALD process and the sufficient diffusion of both WF6 and at-H into deep trenches.

    AB - In this work, the so-called hot-wire (HW) assisted atomic layer deposition (HWALD) technique is employed to grow high-purity α-phase tungsten (W) films at a substrate temperature of 275 °C. The films are deposited on thermally grown silicon dioxide (SiO2) in a home-built hot-wall reactor, using alternating pulses of WF6 and HW-generated atomic hydrogen in the self-limiting surface-reaction manner characteristic for ALD. A W seed layer, needed to enable the HWALD-W process on a SiO2 surface, is formed prior to each deposition. In-situ spectroscopic ellipsometry is used to monitor the growth behavior and film properties. The films exhibit a high-purity (99 at.%) W, according to X-ray photoelectron spectroscopy. The X-ray diffraction scans reveal the existence of α-phase W. The resistivity measurements by means of four point probe, transfer length method test structures and the Drude-Lorentz SE model all reveal a low resistivity of 15 μΩ·cm. The high-resolution transmission electron microscopy analysis shows a uniform and conformal coverage of high aspect ratio structures, confirming the effective ALD process and the sufficient diffusion of both WF6 and at-H into deep trenches.

    KW - Hot wire

    KW - Tungsten

    KW - ALD

    KW - Alpha-phase

    KW - Low resistivity

    KW - High-aspect-ratio substrates

    U2 - 10.1016/j.tsf.2017.12.011

    DO - 10.1016/j.tsf.2017.12.011

    M3 - Article

    VL - 646

    SP - 199

    EP - 208

    JO - Thin solid films

    JF - Thin solid films

    SN - 0040-6090

    ER -