Synthesis and properties of Si and SiGe/Si nanowires

Joan Marie Redwing, Kok Keong Lew, Timothy E. Bogart, Ling Pan, Elizabeth C. Dickey, A. H. Carim, Yanfeng Wang, Marco A. Cabassi, Theresa S. Mayer

Research output: Contribution to journalConference articlepeer-review

11 Scopus citations

Abstract

The fabrication of semiconductor nanowires, in which composition, size and conductivity can be controlled in both the radial and axial direction of the wire is of interest for fundamental studies of carrier confinement as well as nanoscale device development. In this study, group IV semiconductor nanowires, including Si, Ge and Si xGe 1-x alloy nanowires were fabricated by vapor-liquid-solid (VLS) growth using gaseous precursors. In the VLS process, gold is used to form a liquid alloy with Si and Ge which, upon supersaturation, precipitates a semiconductor nanowire. Nanoporous alumina membranes were used as templates for the VLS growth process, in order to control the diameter of the nanowires over the range from 45 nm to 200 nm. Intentional p-type and n-type doping was achieved through the addition of either trimethylboron, diborane or phosphine gas during nanowire growth. The electrical properties of undoped and intentionally doped silicon nanowires were characterized using field-assisted assembly to align and position the wires onto pre-patterned test bed structures. The depletion characteristics of back-gated nanowire structures were used to determine conductivity type and qualitatively compare dopant concentration. SiGe and SiGe/Si axial heterostructure nanowires were also prepared through the addition of germane gas during VLS growth. The Ge concentration in the wires was controllable over the range from 12 % to 25% by varying the inlet GeH 4/SiH 4 ratio.

Original languageEnglish (US)
Pages (from-to)52-59
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume5361
DOIs
StatePublished - Aug 16 2004

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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