Anomalous strain relaxation in SiGe thin films and superlattices

LeGoues, F. K.; Meyerson, B.S.; Morar, J. F.

doi:10.1103/physrevlett.66.2903

Cited by 375 publications

(119 citation statements)

References 14 publications

Supporting

Mentioning

112

Contrasting

Order By: Relevance

“…It results in the formation of a strain-relaxing network of misfit dislocations at the GeSn/Ge interface. A similar relaxation process has been observed in Si/SiGe heterostructures when a low temperature buffer was used as a point defects source, before the growth of a graded, strain relaxing SiGe layer 27 .…”

Section: Resultsmentioning

confidence: 75%

Direct Bandgap Group IV Epitaxy on Si for Laser Applications

et al. 2015

View full text Add to dashboard Cite

The recent observation of a fundamental direct bandgap for GeSn group IV alloys and the demonstration of low temperature lasing provide new perspectives to the fabrication of Si photonic circuits. This work addresses the progress in GeSn alloy epitaxy aiming at room temperature GeSn lasing. Chemical vapor deposition of direct bandgap GeSn alloys with a high -to L-valley energy separation and large thicknesses for efficient optical mode confinement is presented and discussed. Up to 1 µm thick GeSn layers with Sn contents up to 14 at.% were grown on thick relaxed Ge buffers, using Ge 2 H 6 and SnCl 4 precursors. Strong strain relaxation (up to 81 %) at 12.5 at.% Sn concentration, translating into an increased separation between -and L-valleys of about 60 meV, have been obtained without crystalline structure degradation, as revealed by Rutherford backscattering/ion channeling spectroscopy and Transmission Electron Microscopy. Room temperature transmission/reflection and photoluminescence measurements were performed to probe the optical properties of these alloys. The emission/absorption limit of GeSn alloys can be extended up to 3.5 µm (0.35 eV), making those alloys ideal candidates for optoelectronics in the mid-infrared region. Theoretical net gain calculations indicate that large room temperature laser gains should be reachable even without additional doping.

show abstract

Section: Resultsmentioning

confidence: 75%

Direct Bandgap Group IV Epitaxy on Si for Laser Applications

et al. 2015

View full text Add to dashboard Cite

show abstract

“…A thin layer of Au was deposited on the cleaned Si substrate and annealed in the CVD reactor for 10 min at 670°C at 95 Torr in a H 2 ambient. The Si segments of the NWs were grown at 680°C at 30 Torr using the gaseous precursors SiH 4 and HCl in a H 2 ambient. The sample was cooled to 350°C at a nominal rate of 75°C / min with the SiH 4 -HCl-H 2 mixture flowing.…”

mentioning

confidence: 99%

Photoluminescence and Raman scattering in axial Si/Ge nanowire heterojunctions

Chang

Tsybeskov

Sharma

et al. 2009

Applied Physics Letters

View full text Add to dashboard Cite

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at 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/10.1063/1.3240595Applied physics letters, 95, 13, 2009 Photoluminescence and Raman scattering in axial Si/Ge nanowire heterojunctions In crystalline, dislocation-free, Si/Ge nanowire axial heterojunctions grown using the vapor-liquid-solid technique, photoluminescence and Raman spectroscopy reveal a SiGe alloy transition layer with preferential chemical composition and strain. In addition to the lattice mismatch, strain in Si/Ge nanowires is observed from a temperature dependent study to be affected by the difference in Si and Ge thermal expansion. The conclusions are supported by analytical transmission electron microscopy measurements.

show abstract

“…Within the viewing area of the specimen, no clear dislocation pileups or half loops were observed below the LT-Si/ HT-Si 0.6 Ge 0.4 interface, while these dislocation morphologies are commonly seen in compositionally-graded SiGe VSs due to the modified Frank-Read mechanism. 31,32 The high magnification XTEM images, like the one shown in Fig. 6͑b͒, further revealed that the majority of the extended defects were stacking faults primarily located right below the LT-Si/ HT-Si 0.6 Ge 0.4 interface running toward the Si substrate side, but only few of them propagated upward through the HT-Si 0.6 Ge 0.4 layer and reached the top surface.…”

Section: Resultsmentioning

confidence: 95%

Strain relaxation of thin Si0.6Ge0.4 grown with low-temperature buffers by molecular beam epitaxy

Zhao

Hansson

2009

Journal of Applied Physics

View full text Add to dashboard Cite

A double-low-temperature-buffer variable-temperature growth scheme was studied for fabrication of strain-relaxed thin Si 0.6 Ge 0.4 layer on Si͑001͒ by using molecular beam epitaxy ͑MBE͒, with particular focuses on the influence of growth temperature of individual low-temperature-buffer layers on the relaxation process and final structural qualities. The low-temperature buffers consisted of a 40 nm Si layer grown at an optimized temperature of ϳ400°C, followed by a 20 nm Si 0.6 Ge 0.4 layer grown at temperatures ranging from 50 to 550°C. A significant relaxation increase together with a surface roughness decrease both by a factor of ϳ2, accompanied with the cross-hatch/ cross-hatch-free surface morphology transition, took place for the sample containing a low-temperature Si 0.6 Ge 0.4 layer that was grown at ϳ200°C. This dramatic change was explained by the association with a certain onset stage of the ordered/disordered growth transition during the low-temperature MBE, where the high density of misfit dislocation segments generated near surface cusps largely facilitated the strain relaxation of the top Si 0.6 Ge 0.4 layer.

show abstract

Anomalous strain relaxation in SiGe thin films and superlattices

Cited by 375 publications

References 14 publications

Direct Bandgap Group IV Epitaxy on Si for Laser Applications

Direct Bandgap Group IV Epitaxy on Si for Laser Applications

Photoluminescence and Raman scattering in axial Si/Ge nanowire heterojunctions

Strain relaxation of thin Si0.6Ge0.4 grown with low-temperature buffers by molecular beam epitaxy

Contact Info

Product

Resources

About