Raman study of stress effect on Ge nanocrystals embedded in Al2O3

Pinto, S. R. C.; Rolo, Anabela G.; Chahboun, A.; Kashtiban, Reza J.; Bangert, U.; Gomes, M. J. M.

doi:10.1016/j.tsf.2010.03.035

Cited by 22 publications

(17 citation statements)

References 24 publications

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“…These peaks show existence of crystalline Ge (c-Ge) nanoparticles in the film. The peaks are slightly red-shifted and asymmetrically broadened with respect to the Ge bulk peak (300.4 cm -1 ) because of the phonon confinement in the nano-sized particles [17]. The shifts are in accordance with the results of GISAXS analysis showing formation of Ge clusters with radii of 2.5 and 3.8 nm for the films annealed at 700 and 800°C, respectively.…”

Section: Resultssupporting

confidence: 67%

Low-temperature fabrication of layered self-organized Ge clusters by RF-sputtering

et al. 2011

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In this article, we present an investigation of (Ge + SiO2)/SiO2 multilayers deposited by magnetron sputtering and subsequently annealed at different temperatures. The structural properties were investigated by transmission electron microscopy, grazing incidence small angles X-ray scattering, Rutherford backscattering spectrometry, Raman, and X-ray photoelectron spectroscopies. We show a formation of self-assembled Ge clusters during the deposition at 250°C. The clusters are ordered in a three-dimensional lattice, and they have very small sizes (about 3 nm) and narrow size distribution. The crystallization of the clusters was achieved at annealing temperature of 700°C.

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Section: Resultssupporting

confidence: 67%

Low-temperature fabrication of layered self-organized Ge clusters by RF-sputtering

et al. 2011

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“…A shift of the Raman peak appears due to the presence of quantum confinement 31 but also due to stress in the system. 32 The experimentally measured shift implies a germanium NC size of 2 nm. However, the value of the experimentally measured width of the Raman peak corresponds to a germanium NC diameter of ,6 nm, 33 which agrees with the size inferred from the PL according to theoretical calculations.…”

Section: Resultsmentioning

confidence: 95%

Carrier multiplication in germanium nanocrystals

et al. 2015

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Carrier multiplication is demonstrated in a solid-state dispersion of germanium nanocrystals in a silicon-dioxide matrix. This is performed by comparing ultrafast photo-induced absorption transients at different pump photon energies below and above the threshold energy for this process. The average germanium nanocrystal size is approximately 5-6 nm, as inferred from photoluminescence and Raman spectra. A carrier multiplication efficiency of approximately 190% is measured for photo-excitation at 2.8 times the optical bandgap of germanium nanocrystals, deduced from their photoluminescence spectra.

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“…Supersaturated solid solutions (Ge‐rich GeAlO x films) were synthesized by MS, Ge‐ion implantation, EBE, and PLD . Annealing is usually performed between 700 and 900 °C the one of the matrix proportion at about 800 °C .…”

Section: Influence Of Different Matrix Materialsmentioning

confidence: 99%

“…The Ge nanocrystals are generally in spherical shape and uniformly distributed within the matrix . The mean diameter increases with the Ge content (degree of supersaturation) and the annealing temperature . At the interfaces between the nanoparticles and the matrix, Ge sub‐oxides (GeO x ) can be found .…”

Section: Influence Of Different Matrix Materialsmentioning

confidence: 99%

A Review on Ge Nanocrystals Embedded in SiO₂ and High‐k Dielectrics

Lehninger

Beyer

Heitmann

2018

Physica Status Solidi (a)

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In this article, the work on Ge nanocrystals embedded in dielectric films formed by phase separation from supersaturated solid solutions is reviewed. Different methods to synthesize supersaturated solid solutions are covered, e.g., magnetron sputtering, ion implantation, and chemical vapor deposition. The phase separation is activated by subsequent high temperature annealing. Important parameters that influence the formation and properties of the Ge nanocrystals are discussed. Various matrix materials like SiO2, Al2O3, HfO2, HfAlOx, Lu2O3, ZrO2, TaZrOx, and Si3N4 are reported in the literature. The influence of the matrix on the formation and properties of the Ge nanocrystals is addressed in this review. Ge nanocrystals are investigated for applications such as charge storage nodes in nonvolatile memory devices or as silicon technology compatible light emitters. A key to establish these applications seems to be embedding the Ge nanocrystals in still amorphous matrices. This could help to avoid grain boundaries that act as leakage paths for electrical charges (unfavorable for nonvolatile memories) and facilitate defects, which could act as recombination centers (unfavorable for light emitters). A further important point is the synthesis of size and position controlled Ge nanocrystals. Both aspects are reviewed for Ge nanocrystals embedded in the mentioned matrix materials.

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Raman study of stress effect on Ge nanocrystals embedded in Al2O3

Cited by 22 publications

References 24 publications

Low-temperature fabrication of layered self-organized Ge clusters by RF-sputtering

Low-temperature fabrication of layered self-organized Ge clusters by RF-sputtering

Carrier multiplication in germanium nanocrystals

A Review on Ge Nanocrystals Embedded in SiO₂ and High‐k Dielectrics

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Raman study of stress effect on Ge nanocrystals embedded in Al2O3

Cited by 22 publications

References 24 publications

Low-temperature fabrication of layered self-organized Ge clusters by RF-sputtering

Low-temperature fabrication of layered self-organized Ge clusters by RF-sputtering

Carrier multiplication in germanium nanocrystals

A Review on Ge Nanocrystals Embedded in SiO2 and High‐k Dielectrics

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Product

Resources

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A Review on Ge Nanocrystals Embedded in SiO₂ and High‐k Dielectrics