Carrier gas effects on aluminum-catalyzed nanowire growth

Yue Ke, Mel Hainey, Dongjin Won, Xiaojun Weng, Sarah M. Eichfeld, Joan Marie Redwing

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Aluminum-catalyzed silicon nanowire growth under low-pressure chemical vapor deposition conditions requires higher reactor pressures than gold-catalyzed growth, but the reasons for this difference are not well understood. In this study, the effects of reactor pressure and hydrogen partial pressure on silicon nanowire growth using an aluminum catalyst were studied by growing nanowires in hydrogen and hydrogen/nitrogen carrier gas mixtures at different total reactor pressures. Nanowires grown in the nitrogen/hydrogen mixture have faceted catalyst droplet tips, minimal evidence of aluminum diffusion from the tip down the nanowire sidewalls, and significant vapor-solid deposition of silicon on the sidewalls. In comparison, wires grown in pure hydrogen show less well-defined tips, evidence of aluminum diffusion down the nanowire sidewalls at increasing reactor pressures and reduced vapor-solid deposition of silicon on the sidewalls. The results are explained in terms of a model wherein the hydrogen partial pressure plays a critical role in aluminum-catalyzed nanowire growth by controlling hydrogen termination of the silicon nanowire sidewalls. For a given reactor pressure, increased hydrogen partial pressures increase the extent of hydrogen termination of the sidewalls which suppresses SiH4 adsorption thereby reducing vapor-solid deposition of silicon but increases the surface diffusion length of aluminum. Conversely, lower hydrogen partial pressures reduce the hydrogen termination and also increase the extent of SiH4 gas phase decomposition, shifting the nanowire growth window to lower growth temperatures and silane partial pressures.

Original languageEnglish (US)
Article number135605
JournalNanotechnology
Volume27
Issue number13
DOIs
StatePublished - Feb 22 2016

Fingerprint

Aluminum
Nanowires
Hydrogen
Gases
Silicon
Partial pressure
Vapors
Nitrogen
Silanes
Low pressure chemical vapor deposition
Catalysts
Surface diffusion
Growth temperature
Gas mixtures
Gold
Wire
Decomposition
Adsorption

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering

Cite this

Ke, Yue ; Hainey, Mel ; Won, Dongjin ; Weng, Xiaojun ; Eichfeld, Sarah M. ; Redwing, Joan Marie. / Carrier gas effects on aluminum-catalyzed nanowire growth. In: Nanotechnology. 2016 ; Vol. 27, No. 13.
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Carrier gas effects on aluminum-catalyzed nanowire growth. / Ke, Yue; Hainey, Mel; Won, Dongjin; Weng, Xiaojun; Eichfeld, Sarah M.; Redwing, Joan Marie.

In: Nanotechnology, Vol. 27, No. 13, 135605, 22.02.2016.

Research output: Contribution to journalArticle

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AU - Ke, Yue

AU - Hainey, Mel

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AU - Redwing, Joan Marie

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