Depth-dependent disordering in<i>a</i>-Si produced by self-ion-implantation

Zhang, P. X.; Mitchell, I.V.; Tong, B. Y.; Schultz, Peter J.; Lockwood, D. J.

doi:10.1103/physrevb.50.17080

Cited by 30 publications

(17 citation statements)

References 12 publications

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“…26,38 An increase in the structural disorder of a-Si reportedly leads to shifts towards lower wavenumbers (negative shift). 6,9,12,13,23,54 Evidence for the occurrence of both of these counteracting mechanisms was found in this study. Therefore, the observed relative Raman shift of the TO band (Δ ω TO,i ) at an individual point i in the Raman map is the sum of the Raman shift of the TO band due to volume densification (magnitude Δ ω TO,vol,i ) and the opposing shift due to increase in the structural disorder (magnitude Δ ω TO,dis,i ):

Δ ω_{T O, i} = Δ ω_{T O, v o l, i} - Δ ω_{T O, d i s, i} .

Hence, the wavenumber change of the TO band for point i can be calculated as:

δ {ω_{T O, i}}^{*} = Δ ω_{T O, v o l, i} = Δ ω_{T O, i} + Δ ω_{T O, d i s, i} .

The shift due to structural disorder was estimated in the following way.…”

Section: Analysis Of Raman Spectrasupporting

confidence: 77%

“…Therefore, the observed relative Raman shift of the TO band (Δ ω TO,i ) at an individual point i in the Raman map is the sum of the Raman shift of the TO band due to volume densification (magnitude Δ ω TO,vol,i ) and the opposing shift due to increase in the structural disorder (magnitude Δ ω TO,dis,i ):

Δ ω_{T O, i} = Δ ω_{T O, v o l, i} - Δ ω_{T O, d i s, i} .

Hence, the wavenumber change of the TO band for point i can be calculated as:

δ {ω_{T O, i}}^{*} = Δ ω_{T O, v o l, i} = Δ ω_{T O, i} + Δ ω_{T O, d i s, i} .

The shift due to structural disorder was estimated in the following way. Based on various datasets published in previous studies, 16,19,23,54 the wavenumbers of the TO band were plotted as a function of the bond angle distribution (a measure of the structural disorder) for samples exhibiting different degrees of disorder (FIG 3). The data sets were then fit with linear equations.…”

Section: Analysis Of Raman Spectramentioning

confidence: 99%

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In situspectroscopic study of the plastic deformation of amorphous silicon under nonhydrostatic conditions induced by indentation

et al. 2015

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Indentation-induced plastic deformation of amorphous silicon (a-Si) thin films was studied by in situ Raman imaging of the deformed contact region of an indented sample, employing a Raman spectroscopy-enhanced instrumented indentation technique. Quantitative analyses of the generated in situ Raman maps provide unique, new insight into the phase behavior of as-implanted a-Si. In particular, the occurrence and evolving spatial distribution of changes in the a-Si structure caused by processes, such as polyamorphization and crystallization, induced by indentation loading were measured. The experimental results are linked with previously published work on the plastic deformation of a-Si under hydrostatic compression and shear deformation to establish a sequence for the development of deformation of a-Si under indentation loading. The sequence involves three distinct deformation mechanisms of a-Si: (1) reversible deformation, (2) increase in coordination defects (onset of plastic deformation), and (3) phase transformation. Estimated conditions for the occurrence of these mechanisms are given with respect to relevant intrinsic and extrinsic parameters, such as indentation stress, volumetric strain, and bond angle distribution (a measure for the structural order of the amorphous network). The induced volumetric strains are accommodated solely by reversible deformation of the tetrahedral network when exposed to small indentation stresses. At greater indentation stresses, the increased volumetric strains in the tetrahedral network lead to the formation of predominately five-fold coordination defects, which seems to mark the onset of irreversible or plastic deformation of the a-Si thin film. Further increase in the indentation stress appears to initiate the formation of six-fold coordinated atomic arrangements. These six-fold coordinated arrangements may maintain their amorphous tetrahedral structure with a high density of coordination defects or nucleate as a new crystalline β-tin phase within the a-Si network.

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Δ ω_{T O, i} = Δ ω_{T O, v o l, i} - Δ ω_{T O, d i s, i} .

Hence, the wavenumber change of the TO band for point i can be calculated as:

δ {ω_{T O, i}}^{*} = Δ ω_{T O, v o l, i} = Δ ω_{T O, i} + Δ ω_{T O, d i s, i} .

The shift due to structural disorder was estimated in the following way.…”

Section: Analysis Of Raman Spectrasupporting

confidence: 77%

Δ ω_{T O, i} = Δ ω_{T O, v o l, i} - Δ ω_{T O, d i s, i} .

Hence, the wavenumber change of the TO band for point i can be calculated as:

δ {ω_{T O, i}}^{*} = Δ ω_{T O, v o l, i} = Δ ω_{T O, i} + Δ ω_{T O, d i s, i} .

Section: Analysis Of Raman Spectramentioning

confidence: 99%

In situspectroscopic study of the plastic deformation of amorphous silicon under nonhydrostatic conditions induced by indentation

et al. 2015

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“…There have been a number of studies 1,8 that have employed Raman scattering to characterize the phase transition of CVD grown silicon. It is a convenient method to study silicon phase transitions in amorphous silicon (a-Si), 7 polycrystalline silicon ͑poly-Si͒, 8,9 and c-Si materials. 10 Despite its popularity, there have been few reports 11 of the use of Raman scattering spectroscopy to investigate the levels of disorder and the phase transitions in low-temperature MBE-grown Si films.…”

Section: Introductionmentioning

confidence: 99%

Raman and transmission electron microscopy study of disordered silicon grown by molecular beam epitaxy

Tay¹,

Lockwood²,

Baribeau³

et al. 2004

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Raman and transmission electron microscopy study of disordered silicon grown by molecular beam epitaxy Tay, L.; Lockwood, D. J.; Baribeau, J. -M.; Wu, X.; Sproule, G. I.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=fr L'accès à ce site Web et l'utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D'UTILISER CE SITE WEB. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=12744851&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=12744851&lang=fr READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://doi.org/10.1116/1.1676345 Science and Technology A, 22, 3, pp. 943-947, 2004 Raman and transmission electron microscopy study of disordered silicon grown by molecular beam epitaxy Silicon films were deposited by molecular beam epitaxy onto crystalline silicon (c-Si) and native oxide on c-Si ͑001͒ substrates at temperatures ranging from 98 to 572°C. Raman spectroscopy of these films showed that both the short-range disorder and intermediate-range disorder decreases as the deposition temperature increases. The onset of a phase transition in the amorphous Si films can be effectively identified by the appearance of the polycrystalline and crystalline Si Raman bands, which allowed quantification of the crystalline volume fractions present. Both the transmission electron microscopy and Raman results confirmed that films grown on the amorphous substrates at temperatures less than 414°C are entirely amorphous, but exhibit c-Si features at higher temperatures. Films grown on c-Si substrates exhibit a characteristic limiting thickness for epitaxy and the transformation of the resulting upper amorphous layer into crystalline...

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“…The c-Si Raman peak reduction observed in the spectrum of the irradiated sample is evidently caused by the absorption of the laser light in the CIB-disordered silicon. 23 Analysis of the SE, RBS and AFM data testifies that the Si layer modified by the C 60 cluster ion bombardment consists of two sublayers with different nanostructures. These two sublayers are the 24-nm-thick top sublayer assembled from the 5-nm-sized NDs and the deeper 10-nm-thick nc-Si sublayer (transient layer).…”

Section: Resultsmentioning

confidence: 98%

Functionalization of Silicon Crystal Surface by Energetic Cluster Ion Bombardment

Lavrentiev

Vacı́k²,

Dejneka³

et al. 2012

j nanosci nanotechnol

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We report the creation of a functional nanostructure on a Si crystal surface by 200 keV C60(++) cluster ion bombardment (CIB). We found that the modified layer produced by CIB includes two sublayers with different nanostructures. The top 24-nm-thick sublayer is an agglomeration of 5-nm-sized amorphous Si nanodots (a-Si NDs). The deeper 10-nm-thick sublayer is a transient layer of disordered Si as an interface between the a-Si top sublayer and the bulk Si(100). The top a-Si sublayer and the nc-Si transient layer are formed by the local heating effect and shock wave effect, respectively, induced by the cluster ion impacts. The photoluminescence (PL) spectra of the CIB-modified Si samples revealed an emission line centered at a photon energy of 1.92 eV. The absorption spectra of the modified samples exhibit enhanced light absorption at this photon energy. The parameters of the PL line require ascribing the emission origin to the quantum-confinement-induced optical transitions in the a-Si nanodots. The core-shell structure of a-Si NDs is confirmed by detection of an additional PL line centered at 2.5 eV. Analysis of the Rutherford backscattering (RBS) and the PL spectra implies the existence of -Si--O- bonds in the nanodot outer shells, which are responsible for the additional PL line. The obtained results demonstrate the valuable potential of CIB for the controllable fabrication of Si surface nanostructures, which is attractive for optoelectronics and nanoelectronics. The obtained results elucidate the evolution of structure modification occurring in silicon due to the injection of energetic C60 cluster ions with an energy of hundreds of keV.

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Depth-dependent disordering ina-Si produced by self-ion-implantation

Abstract: Raman scattering from amorphous silicon (a-Si) produced by self-ion-implantation reveals an exciting wavelength-dependent

Cited by 30 publications

References 12 publications

In situspectroscopic study of the plastic deformation of amorphous silicon under nonhydrostatic conditions induced by indentation

In situspectroscopic study of the plastic deformation of amorphous silicon under nonhydrostatic conditions induced by indentation

Raman and transmission electron microscopy study of disordered silicon grown by molecular beam epitaxy

Functionalization of Silicon Crystal Surface by Energetic Cluster Ion Bombardment

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