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.}",
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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

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JO - Thin solid films

JF - Thin solid films

SN - 0040-6090

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