Hot-wire assisted atomic layer deposition of Tungsten films

Mengdi Yang

    Research output: ThesisPhD Thesis - Research UT, graduation UT

    128 Downloads (Pure)

    Abstract

    This thesis aims to establish a novel technique of atomic layer deposition (ALD) for the future ultra-large-scale integration (ULSI) of microelectronics. We developed a hot-wire assisted ALD (HWALD), where a heated tungsten (W) filament is utilized instead of a plasma to generate radicals. HWALD is expected to be another candidate for deposition in future ULSI technology. Particularly, this thesis focuses on the application of HWALD for W deposition by providing sequential pulses of atomic hydrogen (at-H) and WF6.

    This thesis demonstrates the results of HWALD W in the cold-/hot-wall reactor. In the cold-wall reactor, β-phase W of high resistivity was obtained, whereas the α-phase W of low resistivity was obtained in the hot-wall reactor.
    The α-phase W possessed a low resistivity of 15 µΩ•cm. Furthermore, a uniform and conformal coverage of HWALD W on high aspect ratio structures (up to an aspect ratio of 36).

    Moreover, an inherent area-selective HWALD of W was proposed. The nucleation and growth of HWALD W on various substrates were studied. No nucleation was found on a thermally-grown SiO2 surface nor on (ALD-grown) TiN and Al2O3 surfaces. On the contrary, HWALD W could be successfully deposited on W and Co surfaces. Due to the nucleation delays on different surfaces, an area-selective HWALD W process was achieved on W/SiO2 and Co/SiO2 patterned surfaces.
    Original languageEnglish
    Awarding Institution
    • University of Twente
    Supervisors/Advisors
    • Schmitz, Jurriaan , Supervisor
    • Kovalgin, Alexey Y., Co-Supervisor
    Award date2 Feb 2018
    Place of PublicationEnschede
    Publisher
    Electronic ISBNs978-90-365-4469-6
    DOIs
    Publication statusPublished - 19 Jan 2018

    Fingerprint

    atomic layer epitaxy
    tungsten
    wire
    theses
    large scale integration
    reactors
    nucleation
    electrical resistivity
    cold walls
    high aspect ratio
    microelectronics
    aspect ratio
    filaments
    hydrogen
    pulses

    Cite this

    Yang, Mengdi . / Hot-wire assisted atomic layer deposition of Tungsten films. Enschede : University of Twente, 2018. 135 p.
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    title = "Hot-wire assisted atomic layer deposition of Tungsten films",
    abstract = "This thesis aims to establish a novel technique of atomic layer deposition (ALD) for the future ultra-large-scale integration (ULSI) of microelectronics. We developed a hot-wire assisted ALD (HWALD), where a heated tungsten (W) filament is utilized instead of a plasma to generate radicals. HWALD is expected to be another candidate for deposition in future ULSI technology. Particularly, this thesis focuses on the application of HWALD for W deposition by providing sequential pulses of atomic hydrogen (at-H) and WF6.This thesis demonstrates the results of HWALD W in the cold-/hot-wall reactor. In the cold-wall reactor, β-phase W of high resistivity was obtained, whereas the α-phase W of low resistivity was obtained in the hot-wall reactor.The α-phase W possessed a low resistivity of 15 µΩ•cm. Furthermore, a uniform and conformal coverage of HWALD W on high aspect ratio structures (up to an aspect ratio of 36).Moreover, an inherent area-selective HWALD of W was proposed. The nucleation and growth of HWALD W on various substrates were studied. No nucleation was found on a thermally-grown SiO2 surface nor on (ALD-grown) TiN and Al2O3 surfaces. On the contrary, HWALD W could be successfully deposited on W and Co surfaces. Due to the nucleation delays on different surfaces, an area-selective HWALD W process was achieved on W/SiO2 and Co/SiO2 patterned surfaces.",
    author = "Mengdi Yang",
    year = "2018",
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    Hot-wire assisted atomic layer deposition of Tungsten films. / Yang, Mengdi .

    Enschede : University of Twente, 2018. 135 p.

    Research output: ThesisPhD Thesis - Research UT, graduation UT

    TY - THES

    T1 - Hot-wire assisted atomic layer deposition of Tungsten films

    AU - Yang, Mengdi

    PY - 2018/1/19

    Y1 - 2018/1/19

    N2 - This thesis aims to establish a novel technique of atomic layer deposition (ALD) for the future ultra-large-scale integration (ULSI) of microelectronics. We developed a hot-wire assisted ALD (HWALD), where a heated tungsten (W) filament is utilized instead of a plasma to generate radicals. HWALD is expected to be another candidate for deposition in future ULSI technology. Particularly, this thesis focuses on the application of HWALD for W deposition by providing sequential pulses of atomic hydrogen (at-H) and WF6.This thesis demonstrates the results of HWALD W in the cold-/hot-wall reactor. In the cold-wall reactor, β-phase W of high resistivity was obtained, whereas the α-phase W of low resistivity was obtained in the hot-wall reactor.The α-phase W possessed a low resistivity of 15 µΩ•cm. Furthermore, a uniform and conformal coverage of HWALD W on high aspect ratio structures (up to an aspect ratio of 36).Moreover, an inherent area-selective HWALD of W was proposed. The nucleation and growth of HWALD W on various substrates were studied. No nucleation was found on a thermally-grown SiO2 surface nor on (ALD-grown) TiN and Al2O3 surfaces. On the contrary, HWALD W could be successfully deposited on W and Co surfaces. Due to the nucleation delays on different surfaces, an area-selective HWALD W process was achieved on W/SiO2 and Co/SiO2 patterned surfaces.

    AB - This thesis aims to establish a novel technique of atomic layer deposition (ALD) for the future ultra-large-scale integration (ULSI) of microelectronics. We developed a hot-wire assisted ALD (HWALD), where a heated tungsten (W) filament is utilized instead of a plasma to generate radicals. HWALD is expected to be another candidate for deposition in future ULSI technology. Particularly, this thesis focuses on the application of HWALD for W deposition by providing sequential pulses of atomic hydrogen (at-H) and WF6.This thesis demonstrates the results of HWALD W in the cold-/hot-wall reactor. In the cold-wall reactor, β-phase W of high resistivity was obtained, whereas the α-phase W of low resistivity was obtained in the hot-wall reactor.The α-phase W possessed a low resistivity of 15 µΩ•cm. Furthermore, a uniform and conformal coverage of HWALD W on high aspect ratio structures (up to an aspect ratio of 36).Moreover, an inherent area-selective HWALD of W was proposed. The nucleation and growth of HWALD W on various substrates were studied. No nucleation was found on a thermally-grown SiO2 surface nor on (ALD-grown) TiN and Al2O3 surfaces. On the contrary, HWALD W could be successfully deposited on W and Co surfaces. Due to the nucleation delays on different surfaces, an area-selective HWALD W process was achieved on W/SiO2 and Co/SiO2 patterned surfaces.

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    M3 - PhD Thesis - Research UT, graduation UT

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