Structural characterization of annealed Si{sub 1-x}C{sub x}/SiC multilayers targeting formation of Si nanocrystals in a SiC matrix

Journal Article · Tue Apr 15 04:00:00 EDT 2008 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2909913· OSTI ID:21137164

Dengyuan, Song; Cho, Eun-Chel; Conibeer, Gavin; Yidan, Huang; Flynn, Chris; Green, Martin A ^[1]

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1. ARC Photovoltaics Centre of Excellence, University of New South Wales, Sydney, New South Wales 2052 (Australia)

Amorphous Si{sub 1-x}C{sub x}/SiC multilayer films were prepared by alternating deposition of Si-rich Si{sub 1-x}C{sub x} and near-stoichiometric SiC layers by using magnetron sputtering. The as-deposited films were annealed at different temperatures (T{sub a}) from 800 to 1100 deg. C. The influence of T{sub a} and Si content in the Si-rich layer on the layered structural stability and on the formation of Si and/or SiC nanocrystals (NCs) is investigated by a variety of analytical techniques, including x-ray reflectivity (XRR), x-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, and Fourier transform infrared spectrometry (FTIR). XRR showed that Si{sub 1-x}C{sub x}/SiC multilayers annealed at temperatures of up to 800 deg. C retain their layered structure. XRD revealed that Si NCs were formed in samples with a high Si content in the Si-rich layer for T{sub a}{>=}800 deg. C. At annealing temperatures of 900 deg. C or greater, the formation of Si NCs was accompanied by the formation of {beta}-SiC NCs. Additionally, the formation of Si and SiC NCs was confirmed by TEM imaging and Raman spectroscopy. The Si-NC size obtained from the TEM micrographs is within the range of 3-5 nm. The {beta}-SiC NCs are smaller (2-3 nm) than Si NCs. Raman analysis identified an {approx}9 cm{sup -1} Raman peak shift in the Si-NC peak to a lower energy with respect to that for bulk Si. FTIR Si-C bond absorption spectra exhibited narrowing of the full width at half maximum and a peak shift toward a higher wave number with increasing T{sub a}. This behavior can be explained by an increase in order as well as an increase in the number of Si-C bonds.

• OSTI ID: 21137164
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 103; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTRA
ANNEALING
DEPOSITION
FOURIER TRANSFORMATION
INFRARED SPECTRA
LAYERS
NANOSTRUCTURES
RAMAN SPECTRA
RAMAN SPECTROSCOPY
REFLECTIVITY
SEMICONDUCTOR MATERIALS
SILICON CARBIDES
SPUTTERING
STOICHIOMETRY
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION