31 research outputs found
Wafer-Scale, Sub-5 nm Junction Formation by Monolayer Doping and Conventional Spike Annealing
We report the formation of sub-5 nm ultrashallow junctions in 4 inch Si
wafers enabled by the molecular monolayer doping of phosphorous and boron atoms
and the use of conventional spike annealing. The junctions are characterized by
secondary ion mass spectrometry and non-contact sheet resistance measurements.
It is found that the majority (~70%) of the incorporated dopants are
electrically active, therefore, enabling a low sheet resistance for a given
dopant areal dose. The wafer-scale uniformity is investigated and found to be
limited by the temperature homogeneity of the spike anneal tool used in the
experiments. Notably, minimal junction leakage currents (<1 uA/cm2) are
observed which highlights the quality of the junctions formed by this process.
The results clearly demonstrate the versatility and potency of the monolayer
doping approach for enabling controlled, molecular-scale ultrashallow junction
formation without introducing defects in the semiconductor.Comment: 21 pages, 5 figure
Note sur le praefectus urbi qu'on appelle Ă tort Aconius Catullinus et sur le proconsul d'Afrique du mĂŞme nom
Histoire ancienne de l'Afrique du Nord. Par Stéphane Gsell. Tomes VII, VIII. Paris: Librairie Hachette, 1928. Pp. 312 et carte; pp. 306 et 2 cartes. 45 francs each.
Inventaire Des Mosaiques de la Gaule et de l'Afrique. 3 vols. By G. Lafarge, Ad. Blanchet, P. Gauckler, F. G. de Pachtere, published under the auspices of the Académie des Inscriptions et Belles-Lettres. ix+234, 352, 120 pp. plates contained in 4 fasciculi (fol.), 30 plates in each. Paris: E. Leroux, 1909–1915.
Le culte de cybèle, mère des dieux, A rome et dans l'Empire Romain. Par H. Graillot. 601 pp. Paris: Fontemoing, 1912.
Anti-Compton gamma spectrometry for environmental samples
The results of the low-level performance of an anti-Compton device are presented. The anti-coincidence action of the NaI detectors lowers the total background of the HPGe detector integrated on the energy range 30 keV to 2730 keV by a factor 8.1 and suppresses the continuum above 300 keV by a factor larger than 10. Qualitative and quantitative results on environmental samples are described to illustrate the improvement of uncertainties determination and the significant reduction of detection limits. This provides ever more accurate and precise data on natural and anthropogenic radionuclides often used as tracers for environmental studies
Specific activity to H*(10) conversion coefficients for in situ gamma spectrometry
The typical situations found in in situ gamma spectrometry have been simulated by Monte Carlo techniques to obtain the energy spectra of the photon fluence rate existing at 1 m above ground. The main difficulty found with the model is its slow convergence. A method to speed up the calculation has been derived. The results of the model have been thoroughly tested against existing data. In a final stage, the specific activity to H*(10) conversion coefficients have been derived for the typical scenarios encountered in the in situ gamma spectrometry. © The Author 2007. Published by Oxford University Press. All rights reserved
Fission product activity ratios measured at trace level over France during the Fukushima accident
International audienceThe nuclear accident of Fukushima Dai-ichi (Japan) which occurred after the tsunami that impacted the northeast coasts of Japan on March 11th, 2011 led to significant releases of radionuclides into the atmosphere and resulted in the detection of those radionuclides at a global scale. In order to track airborne radionuclides from the damaged reactors and to survey their potential impact on the French territory, the French Institute of Radiation Protection and Nuclear Safety (Institut de Radioprotection et de Sureté Nucléaire IRSN) set up an enhanced surveillance system to give quick results as needed and later give quality trace level measurements. Radionuclides usually measured at trace levels such as 137Cs and in a very sporadic way 131I were reported. Radionuclides that we had never measured in air since the Chernobyl accident 134Cs, 136Cs, the mother/daughter pairs 129mTe-129Te and 132Te-132I, and 140La (from the mother-daughter pair 140Ba- 140La) were also reported. Except the 131I/137Cs ratio, activity concentration ratios were constant. These ratios could be used to help source term assessment, or as data for transfer studies realized after the passage of contaminated air masses, typically using the 134Cs/137Cs ratio. © 2013 Elsevier Ltd