Correlation of TEM data with confined phonons to determine strain and size of Ge nanocrystals embedded in SixNy matrix
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Date
2017-06-06
Authors
Bahariqushchi, Rahim
Gündoğdu, Sinan
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Models that use phonon confinement fail to provide consistent results for nanocrystal sizes in differing dielectric matrices due to varying stress experienced by nanocrystals in different dielectric environments. In cases where direct measurement of stress is difficult, the possibility of stress saturation as a function of size opens up a window for the use of phonon confinement to determine size. We report on a test of this possibility in Ge: SixNy system. Ge nanocrystals (NCs) embedded in silicon nitride matrix have been fabricated using plasma enhanced chemical vapor deposition (PECVD) followed by post annealing in Ar ambient. Nanocrystal size dependence of Raman spectra was studied taking into account associated stress and an improved phonon confinement approach. Our analysis show same stress for NCs which have sizes below 7.0 nm allowing the use of phonon confinement to determine the nanocrystal size. The results are compared with TEM data and good agreement is observed.
Description
Keywords
Physics, Quantum-confinement, Raman-scattering, Silicon, Germanium, Photoluminescence, Spectra, Dots, Germanium, Matrix algebra, Phonons, Plasma CVD, Plasma enhanced chemical vapor deposition, Silicon nitride, Confined phonons, Dielectric matrixes, Direct measurement, Ge nanocrystals, Nanocrystal sizes, Phonon confinement, Silicon nitride matrix, Plasma enhanced chemical vapor depositions (PE CVD), Nanocrystals
Citation
Bahariqushchi, R. vd. (2017). ''Correlation of TEM data with confined phonons to determine strain and size of Ge nanocrystals embedded in SixNy matrix''. Superlattices and Microstructures, 111, 90-95.