50 research outputs found
19. Turner (Eric G.). Catalogue of Greek and Latin papyri and ostraca in the possession of the University of Aberdeen. Aberdeen, The University Press, 1939
No full textCollart Paul. 19. Turner (Eric G.). Catalogue of Greek and Latin papyri and ostraca in the possession of the University of Aberdeen. Aberdeen, The University Press, 1939. In: Revue des Études Grecques, tome 53, fascicule 250, Avril-juin 1940. pp. 142-143
Boron deactivation in preamorphized silicon on insulator:Efficiency of the buried oxide as an interstitial sink
Get PDFPreamorphization of ultrashallow implanted boron in silicon on insulator is optimized to produce an abrupt boxlike doping profile with negligible electrical deactivation and significantly reduced transient enhanced diffusion. The effect is achieved by positioning the as-implanted amorphous/crystalline interface close to the buried oxide interface to minimize interstitials while leaving a single-crystal seed to support solid-phase epitaxy. Results support the idea that the interface between the Si overlayer and the buried oxide is an efficient interstitial sink.</p
Uphill diffusion of ultralow-energy boron implants in preamorphized silicon and silicon-on-insulator
Get PDFRedistribution during annealing of low-energy boron (B) implants in silicon on insulator (SOI) structures and in bulk Si has been investigated by comparing secondary ion mass spectrometry (SIMS) and simulated profiles. All the samples have been preamorphized with Ge at different implantation energies in order to investigate the effects of the position of the damage on B diffusion. Different B doses in the range between 2× 1013 and 2× 1015 cm-2 and annealing temperatures between 700 and 1100 °C have been investigated. All SIMS profiles show a B pileup in the first few nanometers of the Si matrix in proximity of the Si surface. The results of our simulations, performed on samples implanted at different doses (below and above the solid solubility), indicate that the B redistribution upon annealing can be explained with a simple model which considers the presence of traps in the surface region, without considering any asymmetric behavior of the dopant diffusion. The sink region is a few monolayers (1-2 nm) for doses of 2× 1013 and 2× 1014 cm-2, and it extends to about 7 nm for the highest dose of 2× 1015 cm-3, in the region of very high B concentration where precipitates and clusters shrink the incoming B atoms. For the two lowest B doses, the amount of B trapped at the surface is maximum at temperatures around 800 °C, when more than 80% of the implanted dopant is made immobile and electrically inactive. In our experimental conditions, i.e., preamorphization performed with constant dose and different implantation energies, the amount of trapped B increases with reducing the depth of the amorphous layer and it is higher in the bulk Si than in SOI.</p
Boron pile-up phenomena during ultra shallow junction formation
Get PDFThe redistribution during annealing of low-energy B implants in SOI structures and in bulk Si have been investigated by comparing Secondary Ion Mass Spectrometry (SIMS) and simulated profiles. Samples preamorphised with Ge at different implantation energies have been prepared in order to investigate the effects of the damage position on B diffusion. The specimens have been subsequently B implanted at 500 eV with doses 2×1013 and 2×1014 cm-2 and annealed between 700 and 1100°C. SIMS profiles show a B pile-up in the first few nanometres of the Si matrix on the Si surface. Simulations of diffused profiles indicate that the B redistribution upon annealing can be explained by assuming that the mobility of the dopant which arrives in proximity of the surface is practically annulled. The amount of B trapped at the surface is maximum at the temperatures around 800°C, when more than 80% of the implanted dopant is made immobile and electrically inactive. The trapped B increases with reducing the depth of the amorphous layer and it is higher in the bulk Si than in SOI. By comparing Hall measurements and the amount of B not trapped at the surface, we also estimate the amount of B that aggregates inside the Si lattice in form of clusters (BICs). For the B dose of 2×1014 cm-3, after isochronal annealing of 60 s, the amount of BICs is about 3-4×10 13 cm-2at the lowest temperatures and tends to vanish at high temperatures.</p
L'Europe occidentale entre le baroque et le rococo : Série F : Ballet et Opéra
No full textComprend : Pigmalion : acte de ballet / Jean-Philippe Rameau ; Eric Marion, ténor ; Andrée Esposito, Claudine Collart et Edith Selig, sopranos ; Choeur Raymond Saint-Paul dir. Roger List et Orchestre de chambre des Concerts Lamoureux dir. Marcel Couraud - Troisième concert des Indes Galantes / Jean-Philippe Rameau ; Andrée Esposito, soprano ; l'Orchestre de chambre des Concerts Lamoureux dir. Marcel Couraud, avec Janine Reiss, clavecinBnF-Partenariats, Collection sonore - BelieveContient une table des matière
Vacancy-engineering implants for high boron activation in silicon on insulator
Get PDFThe formation of boron interstitial clusters is a key limiting factor for the fabrication of highly-conductive ultrashallow doped regions in future silicon-based device technology. Optimized vacancy engineering strongly reduces boron clustering, enabling low-temperature electrical activation to levels rivalling what can be achieved with conventional pre-amorphization and solid-phase epitaxial regrowth. An optimized 160-keV silicon implant in a 55/145nm silicon-on-insulator structure enables stable activation of a 500eV boron implant to a concentration ~ 5x1020cm-3
L'Europe occidentale entre le baroque et le rococo : Série F : Ballet et Opéra
No full textComprend : Pigmalion : acte de ballet / Jean-Philippe Rameau ; Eric Marion, ténor ; Andrée Esposito, Claudine Collart et Edith Selig, sopranos ; Choeur Raymond Saint-Paul dir. Roger List et Orchestre de chambre des Concerts Lamoureux dir. Marcel Couraud - Troisième concert des Indes Galantes / Jean-Philippe Rameau ; Andrée Esposito, soprano ; l'Orchestre de chambre des Concerts Lamoureux dir. Marcel Couraud, avec Janine Reiss, clavecinBnF-Partenariats, Collection sonore - BelieveContient une table des matière
Het hoogh-loffelijcke ivbel-iaer vande [...] societeyt Jesu, welckers cloosteren inden jare 1540 [...] bevestight zijn. Waer in grondelijck verhaelt wort alle de gedenckweerdighste geschiedenissen ...... /
No full textThe author and printer are fictitiousThis work is a pasticheBacker-Sommervogel [S.J.] II, 1291, nr. 1Europeana-GoogleBook
Expression of the mouse dihydrofolate reductase gene, 2000
Get PDFYeast Artificial Chromosomes (YACs) containing the mouse DHFR gene were isolated, mapped and transferred into DHFR deficient Chinese Hamster Ovary (DHFR'DEFICIENT CHO) cells. The steady state levels of mouse DHFR mRNA species were analyzed during resting and growth stimulation, in an unamplified cell line. Growth arrest was obtained by serum deprivation, and growth stimulation by subsequent serum restoration. Analysis of the cell cycle was performed by Flow Cytometry. We have examined the expression and regulation of endogenous DHFR mRNA in 3T3 cells and observed a 2 fold increase in DHFR mRNA levels in cells predominantly in S phase (growing for 22H after serum stimulation) vs. arrested cells. Also, we have observed a 2 fold increase in DHFR mRNA levels in CHO cells containing the mouse DHFR gene, cultured under the same conditions. These results indicated that the transferred YAC gene is expressed and regulated in a growth dependent manner and at levels nearly identical to the endogenous 3T3 DHFR gene. We concluded that transfer of a YAC containing the mouse DHFR gene into an established DHFR'DEFICIENT CHO cell line, results in statistical comparable expression of the mouse DHFR gene. We concluded that this is an excellent system to study the expression of the mouse DHFR gene, with complete gene sequences
Les concepts de développement durable et de sécurité alimentaire à la lumière des relations extérieures de l’Europe
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