Modification of germanium nanoclusters in GeO x films during isochronous furnace and pulse laser annealing

Marin, D. V.; Володин, В. А.; Gorokhov, E. B.; Shcheglov, D. A.; Латышев, А. В.; Vergnat, M.; Koch, Jürgen; Chichkov, Boris N.

doi:10.1134/s1063785010050159

Cited by 9 publications

(5 citation statements)

References 4 publications

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“…Laser pulse processing of surfaces and thin films is a useful tool for purposes such as the amorphous thin films crystallization [1–6], surface nanostructuring [7–10], laser-induced thin film dewetting [11–12], phase transformation and modification of physical properties of thin films [13–16]. The laser fluence values used for these applications are below the ablation threshold of the irradiated material in order to prevent a loss of material during laser processing.…”

Section: Introductionmentioning

confidence: 99%

Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

Teodorescu¹,

Ghica²,

Maraloiu³

et al. 2015

Beilstein J. Nanotechnol.

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SummaryLaser pulse processing of surfaces and thin films is a useful tool for amorphous thin films crystallization, surface nanostructuring, phase transformation and modification of physical properties of thin films. Here we show the effects of nanostructuring produced at the surface and under the surface of amorphous GeTiO films through laser pulses using fluences of 10–30 mJ/cm2. The GeTiO films were obtained by RF magnetron sputtering with 50:50 initial atomic ratio of Ge:TiO2. Laser irradiation was performed by using the fourth harmonic (266 nm) of a Nd:YAG laser. The laser-induced nanostructuring results in two effects, the first one is the appearance of a wave-like topography at the film surface, with a periodicity of 200 nm and the second one is the structure modification of a layer under the film surface, at a depth that is related to the absorption length of the laser radiation. The periodicity of the wave-like relief is smaller than the laser wavelength. In the modified layer, the Ge atoms are segregated in spherical amorphous nanoparticles as a result of the fast diffusion of Ge atoms in the amorphous GeTiO matrix. The temperature estimation of the film surface during the laser pulses shows a maximum of about 500 °C, which is much lower than the melting temperature of the GeTiO matrix. GeO gas is formed at laser fluences higher than 20 mJ/cm2 and produces nanovoids in the laser-modified layer at the film surface. A glass transition at low temperatures could happen in the amorphous GeTiO film, which explains the formation of the wave-like topography. The very high Ge diffusivity during the laser pulse action, which is characteristic for liquids, cannot be reached in a viscous matrix. Our experiments show that the diffusivity of atomic and molecular species such as Ge and GeO is very much enhanced in the presence of the laser pulse field. Consequently, the fast diffusion drives the formation of amorphous Ge nanoparticles through the segregation of Ge atoms in the GeTiO matrix. The nanostructuring effects induced by the laser irradiation can be used in functionalizing the surface of the films.

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Section: Introductionmentioning

confidence: 99%

Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

Teodorescu¹,

Ghica²,

Maraloiu³

et al. 2015

Beilstein J. Nanotechnol.

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“…The main reason was that germanium monooxide was a metastable material readily undergoing decomposition even without any additional heating (Marin, 2010). Second, the layers of amorphous germanium dioxide rapidly dissolve in water (Kamata, 2008).…”

Section: Introductionmentioning

confidence: 99%

GeO2 Films with Ge-Nanoclusters in Layered Compositions: Structural Modifications with Laser Pulses

Gorokhov¹,

Astankova²,

Komonov³

2012

Laser Pulses - Theory, Technology, and Applications

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“…Two series of films were prepared by (1) evaporation of GeO 2 and SiO 2 powdered sources in accordance with the chemical composition, which we will refer to as GeO[SiO 2 ], and (2) evaporation of GeO 2 and SiO powdered sources in accordance with the chemical composition, marked as GeO[SiO] film. Note that, according to previous studies [21,22] on the condition of the evaporation of germanium dioxide powder, GeO x films of a composition very close to germanium monoxide (x~1 ÷ 1.1) were deposited on the substrate. Presumably, this was due to the fact that germanium monoxide is a very volatile compound (i.e., it evaporates when an electron beam heats the targeted germanium dioxide powder and condenses on a cold substrate).…”

Section: Methodsmentioning

confidence: 99%

Resistive Switching in Non-Stoichiometric Germanosilicate Glass Films Containing Ge Nanoclusters

et al. 2020

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Metal–insulator–semiconductor (MIS) structures based on thin GeO[SiO2] and GeO[SiO] films on Si substrates were fabricated with indium-tin-oxide as a top electrode. The samples were divided it two series: one was left as deposited, while the second portion of MIS structures was annealed at 500 °C in argon for 20 min. The structural properties of as-deposited and annealed non-stoichiometric germanosilicate (GeSixOy) films were studied using X-ray photoelectron spectroscopy, electron microscopy, Raman and infrared absorption spectroscopy, spectral ellipsometry, and transmittance and reflectance spectroscopy. It was found that the as-deposited GeO[SiO] film contained amorphous Ge clusters. Annealing led to the formation of amorphous Ge nanoclusters in the GeO[SiO2] film and an increase of amorphous Ge volume in the GeO[SiO] film. Switching from a high resistance state (HRS OFF) to a low resistance state (LRS ON) and vice versa was detected in the as-deposited and annealed MIS structures. The endurance studies showed that slight degradation of the memory window occurred, mainly caused by the decrease of the ON state current. Notably, intermediate resistance states were observed in almost all MIS structures, in addition to the HRS and LRS states. This property can be used for the simulation of neuromorphic devices and related applications in data science.

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Modification of germanium nanoclusters in GeO x films during isochronous furnace and pulse laser annealing

Cited by 9 publications

References 4 publications

Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

GeO2 Films with Ge-Nanoclusters in Layered Compositions: Structural Modifications with Laser Pulses

Resistive Switching in Non-Stoichiometric Germanosilicate Glass Films Containing Ge Nanoclusters

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