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Synthèse et propriétés de monocristaux, de poudres, films minces ou hétérostructures

Etudes à l'interface avec la matière biologique

> LMGP_ Recherche > Nano

Caractérisations avancées

Cet axe de recherche comporte deux thèmes
 
L’un est centré sur l’étude in situ du stade précoce de la croissance, notamment par l’utilisation de techniques optiques (ellipsométrie, mesure de contraintes) et/ou du rayonnement synchrotron (réflectivité, fluorescence, absorption, diffusion aux petits angles, diffraction). L'objectif de ce travail est de contrôler la croissance de films ultra-minces (oxydes, sulfures) et des nanostructures à l’échelle atomique, par l’étude des mécanismes et de la cinétique de croissance. Pour cela, nous développons et utilisons des instruments et des méthodes expérimentales spécifiques afin d’obtenir des informations chimiques, spectroscopiques, structurales et optiques en cours et dès les premiers stades de la croissance. Les procédés ciblés sont le dépôt alterné de couches atomiques (ALD), le dépôt chimique en phase vapeur (MOCVD) et le dépôt hydrothermal (CBD). Un deuxième thème rassemble les caractérisations chimiques et structurales avancées de nanostructures et nanomatériaux, pratiquées ex situ (après fabrication) ou in situ pour étudier l’effet d’une sollicitation externe (température, recuit sous atmosphère contrôlée, champs électromagnétiques, forces électrochimiques,....), ou operando. Les techniques expérimentales principalement utilisées sont la microscopie électronique à transmission, la diffusion des rayons X (résonance), l'absorption des rayons X et les spectroscopies de photoélectrons.

Collaborateurs


SIMAP, Grenoble INP, Grenoble (France) – R. Boichot, E. Blanquet, A. Crisci
IN2MP, Marseille (France) – M-I Richard, O. Thomas
Synchrotron SOLEIL, St Aubin (France) – G. Ciatto, N. Aubert
Argonne National Laboratory – D. Fong
BM2-D2AM at ESRF, ESRF (France)
Zaragoza University, Zaragoza (Spain) - M.G. Proietti-Cecconi
CEA-INAC, Grenoble (France) – B. Daudin
CEA-Leti, Grenoble (France) – S. Cadot, F. Martin, P. Rodriguez

Personnel

H. Renevier,
S. Pignard,
M. Boudard,
Evgenie Skopin (PostDoc)
J.-L. Deschanvres (FunSurf),
D. Munoz-Rojaz (Funsurf)

Projects


EMOUVAN (2016-2019). EMissiOn de lumière UV Avec des Nanofils UV light emission with nanowires.
ANR

FACCTS (2016-2018). Coherent x-ray studies of phase transitions in the complex oxides. France And Chicago Collaborating in The Sciences

VIGOS (2016-2017). Visualising the incipient growth of ZnO ultra thin films on InGaAs for tailoring contact resistivity. Communauté Université Grenoble Alpes. PhD funding from labex MINOS.

SON (2011-2014). The Synthesis of Nanostructured Oxides. Dr. Dillon FONG’s Chair of excellence (Argonne National Laboratory.
Nanosciences Fondation

MOON (2011-2015). Optimisation de la croissance par MOCVD/ALD d'Oxyde Nanostructuré pour la conversion de l'énergie solaire par couplage entre la modélisation et l'analyse in situ par le rayonnement synchrotron et par des méthodes optiques.
ANR P2N.

RL1: in situ Growtth Studies


Highligth 1
Atomic layer deposition (ALD) is a chemical vapor-based thin film deposition technique which relies on the sequential and self-terminating gas–surface reactions of two gaseous reactants. It enables atomic level thickness control, tunable film composition and an unmatched ability to produce conformal films on complex 3D-shaped surfaces. Indeed, ALD has emerged as a mainstream deposition tool for many industrial and research applications in the fields of micro-electronics and energy.
To improve control over the ALD process, and ultimately the ability to tailor the properties of nanostructured materials atomically, we use a custom built reactor that we move to Synchrotron Radiation facilities (SOLEIL, ESRF)
A complementary suite of in situ synchrotron X-ray techniques (fluorescence, reflectivity, grazing-incidence diffraction, absorption) has used to investigate both structural and chemical evolution during ZnO ALD on a-SiO2 (amorphous), c- Al2O3 (cristalline) and In0.47Ga0.53As substrates [1, 2, 3], enable us to gain a deep understanding of growth behavior and elucidate the atomistic processes taking place during the initial stages of growth.
[1] Evolution of Crystal Structure During the Initial Stages of ZnO Atomic Layer Deposition. R. Boichot et al., J. Chem. Mater. (2016) 28, 592
[2] An Atomistic View of the Incipient Growth of Zinc Oxide Nanolayers. M. H. Chu et al., Cryst. Growth Des. (2016) 16, 5399
[3] SIRIUS: A new beamline for in situ X-ray diffraction and spectroscopy studies of advanced materials and nanostructures at the SOLEIL Synchrotron G. Ciatto et al., Thin Solid Films (2016) 617, 48


Highligth 2
The Initial Stages of ZnO Atomic Layer Deposition on Atomically Flat In0.53Ga0.47As Substrates
ZnO has been identified a good candidate material to be inserted as a tunneling insulator layer at the metal- In0.53Ga0.47As junction. A key consideration in many modern devices is the atomic structure of the hetero-interface, which often ultimately governs the electronic or chemical process of interest. A complementary suite of in situ synchrotron X-ray techniques (?uorescence, re?ectivity and absorption) as well as modeling was used to investigate both structural and chemical evolution during the initial growth of ZnO by atomic layer deposition (ALD) on In0.53Ga0.47As substrates [4]. Prior to steady-state growth behavior, we discover a transient regime characterized by two stages. First, substrate-inhibited ZnO growth takes place on InGaAs terraces. This leads eventually to the formation of a 1-nm-thick, two-dimensional (2D) amorphous layer. Second, the growth behavior and its modeling suggest the occurrence of dense island formation, with an aspect ratio and surface roughness that depends sensitively on the growth condition. Finally, ZnO ALD on In0.53Ga0.47As is characterized by 2D steady-state growth with a linear growth rate of 0.21 nm.cy?1, as expected for layer-by-layer ZnO ALD.

 [4] The Initial Stages of ZnO Atomic Layer Deposition on Atomically Flat In0.53Ga0.47As Substrates E. Skopin et al., Nanoscale (2018)

RL2: Advanced structural, chemical, electrical characterizations


Ensemble averaged nanowire polarity determined by X-ray anomalous diffraction (X-ray resonant scattering).
Polarity is an intrinsic property of non-centrosymmetric crystalline structures such as GaN or ZnO wurtzite which is determined at the early stage of growth. Therefore, the knowledge of the NWs polarity for different growth parameters, substrate and surface preparations gives, in turn, much information on the NWs growth mechanism. Besides, the nanowire polarity affects surface configuration so the reactivity, nucleation and growth, electro-optical properties, and nanoscale-engineering device. Anomalous Diffraction (or resonant X-ray scattering) was used to study GaN NWs grown by PAMBE directly on Si substrate [5]. Experimental data clearly shows that as grown-NWs are N-polar (the up ended - NWs are Ga-polar). A similar study was performed to demonstrate the polarity transfert from ZnO seed layer grown by Chemical Bath Deposition on Si substrate to CBD ZnO nanowires [6].



 

[6] Quantitative and simultaneous analysis of the polarity of polycrystalline ZnO seed layers and related nanowires grown by wet chemical deposition. S. Guillemin et al., Nanotechnology 28 (2017) 095704
 
  Other relevant papers
[5] Polarity of GaN Nanowires Grown by Plasma-Assisted Molecular Beam Epitaxy on Si(111). K. Hestroffer, C. Leclere, C. Bougerol, H. Renevier, Bruno Daudin. Phys. Rev. B 84, (2011), 245302.
[6] XAFS atomistic insight of the oxygen gettering in Ti/HfO2 based OxRRAM. R. Viennet, H. Roussel, L. Rapenne, J. L. Deschanvres, V. Jousseaume, E. Jalaguier, M.G. Proeitti, H. Renevier. Phys. Rev. Mater. 2, (2018), 055002.
[7] Diffraction Anomalous Fine Structure : basic formalism. H. Renevier, M.G. Proietti. International Tables for Crystallography I. Accepted.
[8] Diffraction Anomalous Fine Structure : experiment and data analysis. H. Renevier, M.G. Proietti. International Tables for Crystallography I. Accepted.

mise à jour le 17 décembre 2018

  • Tutelle CNRS
  • Tutelle Grenoble INP
Univ. Grenoble Alpes