Hot-wire assisted atomic layer deposition of Tungsten films

Mengdi Yang

Research output: ThesisPhD Thesis - Research UT, graduation UT

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.
LanguageEnglish
Awarding Institution
  • University of Twente
Supervisors/Advisors
  • Schmitz, Jurriaan , Supervisor
  • Kovalgin, Alexey Y., Supervisor
Award date2 Feb 2018
Place of PublicationEnschede
Electronic ISBNs978-90-365-4469-6
DOIs
StatePublished - 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, 2018. 135 p.
@phdthesis{3089c960e783437e87b9ee83bb7a324f,
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",
month = "1",
day = "19",
doi = "10.3990/1.9789036544696",
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Yang, M 2018, 'Hot-wire assisted atomic layer deposition of Tungsten films', University of Twente, Enschede. DOI: 10.3990/1.9789036544696

Hot-wire assisted atomic layer deposition of Tungsten films. / Yang, Mengdi .

Enschede, 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

CY - Enschede

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