Incorporation of oxygen and nitrogen in ultrathin films of SiO/sub 2 annealed in NO

The areal densities of oxygen and nitrogen incorporated into ultrathin films of silicon dioxide during rapid thermal processing in nitric oxide, as well as the regions where these incorporations took place, were determined by combining nuclear reaction analysis and narrow nuclear resonance depth profiling with isotopic enrichment of the processing gas. Oxygen is seen to incorporate in the near-surface and near-interface regions of the oxynitride films, whereas nitrogen is incorporated only in the near-interface regions. The growth of the oxynitride film is very moderate as compared to that of a SiO2 film in dry O2 . The thermal oxynitridation of ultrathin SiO2 films takes place by two mechanisms in parallel: the major part of the NO molecules, which react with the silica, decompose in the near-surface region, the O atoms being exchanged for O atoms preexistent in this region of the SiO2 films; a minor portion of the NO molecules diffuse through the silica film in interstitial sites, without reacting with it, to react at the oxynitride/Si interface

Rapport de la CRI

Trimaille Isabelle. Rapport de la CRI. In: Diplômées, n°257, 2016. pp. 23-24

Relations internationales

Trimaille Isabelle. Relations internationales. In: Diplômées, n°251, 2014. Les femmes : La Guerre et la Paix. p. 231

Growth of SiO2 on SiC by dry thermal oxidation: mechanisms

International audienceSiC is unique amongst the wide bandgap semiconductors in that the natural thermal oxide is stoichiometric SiO2, as is the case for silicon. The possibility of producing devices such as MOSFET in which thermal SiO2 is used as the gate insulator has motivated substantial work aimed at understanding the morphology and electrical properties of the SiO2/ SiC interface and the processes responsible for thermal oxide growth. The oxide growth kinetics are quite different, parallel and anti- parallel to the crystal polar direction. We review the experimental study of the nature of the thermal oxide grown in ultra- dry oxygen and of the extended interfacial region at the SiO2/ SiC interface on the nominally Si- terminated and C- terminated polar surfaces of hexagonal polytypes of SiC, highlighting how the use of stable isotopic tracing has helped to clarify processes for which kinetics measurements alone do not prove to be sufficiently incisive

The contribution of stable isotopic tracing, narrow nuclear resonance depth profiling, and a simple stochastic theory of charged particle energy loss to studies of the dry thermal oxidation of SiC

15th International Workshop on Inelastic Ion-Surface Collisions (IISC-15), Ise Shima, JAPAN, OCT 17-22, 2004International audienceWe present the stochastic approach to calculating fast charged particle energy distributions when penetrating matter, and nuclear reaction yield curves obtained when the energy of a beam incident on a target is scanned about the energy of narrow nuclear resonances, such as O-18(p,alpha)N-15 at 151 keV. In particular we present new calculations that show the insensitivity of the final calculations to the detailed form of the energy loss distribution assumed for independent single ion-atom collisions. We present application of narrow resonance profiling with O-18 stable isotopic tracing to the study of the dry thermal oxidation mechanisms of silicon carbide, yielding insights into the process that cannot be obtained by other means. (c) 2005 Elsevier B.V. All rights reserved

Thermal ammonia nitridation on HfO2 and hafnium silicates thin films

17th International Conference on Ion Beam Analysis, Seville, SPAIN, JUN 26-JUL 01, 2005International audienceIn this paper we use isotopic tracing experiments with (NH3)-N-15 and (NH3)-N-14 to investigate the nitridation mechanisms on both hafnium silicates films (40-175 angstrom) and HfO2 (50 angstrom) films deposited by MOCVD on silicon substrate covered by a 10-15 angstrom interfacial SiO2 layer. Nitrogen profiles in the films were obtained through nuclear resonance profiling (NRP) with the N-15(p,alpha gamma)C-12 resonance at 429 keV and the total amounts of atomic species and the overall stoichiometry were obtained by RBS and NRA. In the silicate films, nitrogen is incorporated both into surface and bulk regions. For HfO2, lowering the ammonia pressure favors the fixation of nitrogen in the near surface region of film. This phenomenon is not observed in the case of silicate films. The pressure dependence of near surface nitrogen incorporation in HfO2 films could be related to the formation of oxygen vacancies and opens a way to control the diffusion barrier needed in the gate dielectric. (c) 2006 Elsevier B.V. All rights reserved

Assemblée Générale du GEFDU (Groupe Européen des Femmes Diplômées de l'Université) Vienne, 3-6 septembre 2009

Jonczy Marie-José, Hostasch Lore, Trimaille Isabelle, John-Mikolajewski Vera, Auzac Evelyne d'. Assemblée Générale du GEFDU (Groupe Européen des Femmes Diplômées de l'Université) Vienne, 3-6 septembre 2009 . In: Diplômées, n°230, 2009. pp. 204-211

Defect and composition analysis of as-deposited and nitrided (100)Si/SiO2/Hf1-xSixO2 stacks by electron paramagnetic resonance and ion beam analysis

International audienceThe defects in the as-deposited and nitrided Si/SiO2/Hf1-xSiO(2) stacks have been analysed by EPR spectroscopy. The interface defects at the Si/SiO2 section are identical to those in the classical Si/SiO2 case and their concentration is not influenced by the hafnium silicate layer growth. As deposited hafnium silicate layers present in addition a defect located in the near surface region with a high concentration; it shows the characteristics of the EX center in SiO2 including low temperature hydrogen passivation. In the nitrided samples both the interface defects and the EX center are no longer observed. Additional annealing shows this to be related to a hydrogen passivation during the nitridation. The composition of the as deposited Hf1-xSixO2 layers have been analysed by ion beam analysis. Their thermal nitridation by NH3 has been investigated as a function of the annealing conditions. The hafnium silicate layers incoporate N up to some at% in the entire layer whereas hafnium oxide layers show no significant nitrogen incorporate into the bulk of the film

Nitrogen transport during rapid thermal growth of silicon oxynitride films in N/sub 2/ O

We investigated the transport of nitrogenous species during rapid thermal growth of silicon oxynitride films on Si in N2O, using N isotopic tracing and high resolution depth profiling techniques. The results indicate that the diffusion of nitrogenous species ~most probably NO! through the growing oxynitride film to react with Si at the oxynitride/Si interface, induces the incorporation of N near this interface. This mechanism acts in parallel with a site-to-site jump mechanism ~interstitialcy or vacancy! of diffusion and chemical reaction of nitrogenous species in the volume of the growing oxynitride film. The characteristic N accumulation only near the interface obtained by rapid thermal processing growth in N2O is due to the removal of N from the near surface region of the films, here attributed to atomic exchanges O-N taking place during growth. Furthermore, N-N exchange was also observed

Isotopic tracing during rapid thermal growth of silicon oxynitride films on Si in O2, NH3, and N2O

We performed isotopic tracing of O, N, and H during rapid thermal growth of silicon oxynitride films on silicon in two different sequential, synergistic gas environments: O2, followed by NH3, then followed by N2O; and N2O, followed by NH3. Using nuclear reaction analysis and high resolution depth profiling, we demonstrate that the oxynitride films grow by means of thermally activated atomic transport involving the three traced species. Concomitantly, isotopic exchange processes take place. Growth in these sequential gas environments leads to oxynitride films with N concentration profiles and H concentrations different from those obtained by commonly used processes like thermal growth in N2O only or thermal nitridation of SiO2 films in NH3