Publications by authors named "Elisabeth Blanquet"

4 Publications

  • Page 1 of 1

The initial stages of ZnO atomic layer deposition on atomically flat InGaAs substrates.

Nanoscale 2018 Jun;10(24):11585-11596

Univ. Grenoble Alpes, CNRS, Grenoble INP, LMGP, F-38000 Grenoble, France.

InGaAs is one of the III-V active semiconductors used in modern high-electron-mobility transistors or high-speed electronics. ZnO is a good candidate material to be inserted as a tunneling insulator layer at the metal-semiconductor 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. Here, a complementary suite of in situ synchrotron X-ray techniques (fluorescence, reflectivity and absorption) as well as modeling is used to investigate both structural and chemical evolution during the initial growth of ZnO by atomic layer deposition (ALD) on In0.53Ga0.47As substrates. 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.
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http://dx.doi.org/10.1039/c8nr02440eDOI Listing
June 2018

Stability of high temperature chemical vapor deposited silicon based structures on metals for solar conversion.

J Nanosci Nanotechnol 2011 Sep;11(9):8318-22

SIMaP Grenoble INP UJF, CNRS, 38402 Saint Martin d'Hères, France.

Highly crystallized silicon layers were grown on metal sheets at high temperature (950 degrees C) by thermal CVD from silane. An intermediate buffer layer was mandatory to prevent interdiffusion and silicide formation but also to compensate lattice parameters and thermal expansion coefficients mismatches between metal and silicon and ideally transfer some crystalline properties (grain size, texture) from the substrate to the silicon layer. After a thermodynamic study, aluminum nitride or titanium nitride diffusion barrier layers were selected and processed by CVD. The structure and the interfaces stabilities of these silicon/nitride/metal stacks were studied by field effect gun scanning and transmission electron microscopy, X-ray diffraction, Raman and energy dispersive X-ray spectroscopy. As a result, TiN deposited by CVD appears to be an efficient material as a buffer layer between steel and silicon.
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http://dx.doi.org/10.1166/jnn.2011.5077DOI Listing
September 2011

Cracking study of pentakis(dimethylamino)tantalum vapors by Knudsen cell mass spectrometry.

Rapid Commun Mass Spectrom 2010 Oct;24(20):2949-56

Science et Ingénierie des Matériaux et Procédés (SIMaP, Associated to CNRS-UMR 5266 UJF/INP-Grenoble), 1130 rue de la piscine, B.P. 75, 38402 Saint Martin d'Hères, France.

Organometallic molecules are commonly used as gaseous precursors in Atomic Layer Deposition/Chemical Vapor Deposition (ALD/CVD) processes. However, the use of these molecules, which are generally thermally unstable at temperatures close to the deposition temperature, requires an understanding of their gas-phase chemical behavior. The thermal cracking of the gaseous precursor, pentakis(dimethylamino) tantalum (PDMAT), generally adopted in the ALD/CVD TaN deposition processes, has been studied in the temperature range from 343 to 723K using a specific reactor coupled with a high-temperature mass spectrometer. This reactor - built as tandem Knudsen cells - consists of two superimposed cells. The first stage reactor - an evaporation cell - provides an input saturated vapor flow operating from room temperature to 333K. The second stage cell, named the cracking cell, operated from 333 to 723K in the present study. Experiments showed the appearance of many gaseous species when the cracking temperature increased and, in particular, dimethylamine, corresponding to the saturated organic branches of PDMAT. Decomposition products of the HNC(2)H(6) branch were observed at relatively high temperature, namely above 633K. This gas-phase study - as for the preceding saturated one - shows the presence of oxygen-containing molecules in PDMAT cracked vapor. Thus, it explains the systematic presence of oxygen contamination in the deposited TaN films observed in ALD/CVD industrial processes.
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http://dx.doi.org/10.1002/rcm.4727DOI Listing
October 2010

A special reactor coupled with a high-temperature mass spectrometer for the investigation of the vaporization and cracking of organometallic compounds.

Rapid Commun Mass Spectrom 2009 Mar;23(6):793-800

Sciences et Ingénierie des Matériaux et Procédés, CNRS UMR 5266-UJF/Grenoble-INP, B.P. 75, Domaine Universitaire, 1130 rue de la Piscine, F-38402 Saint Martin d'Hères, France.

A special reactor coupled to a high-temperature mass spectrometer was specifically designed for the study of vaporization and thermal cracking of organometallic precursors. This reactor has two kinds of settings. One is a single Knudsen effusion cell which enables the analysis of the composition of saturated vapors and the determination of the partial pressure of each gaseous molecule in equilibrium with its condensed phase. This cell is an evaporation/sublimation cell (operating from 243 to 473 K), which can be tightly closed--like a vacuum chamber--in order to protect organometallic compounds against moisture and atmospheric components. This cell can be independently weighed usefully to evaluate the equilibrium vapor pressures of the sample using the mass-loss method. During experiments, the effusion aperture is externally opened for direct mass spectrometric measurements. The other setting dedicated to the study of thermal decomposition of gaseous molecules consists of a set of tandem cells: the previously described Knudsen cell and a cracking cell (operating from 293 to 973 K).
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http://dx.doi.org/10.1002/rcm.3942DOI Listing
March 2009