Three dimensional distributions of arsenic and platinum within NiSi contact and gate of an n-type transistor

Atom probe tomography was used to study the redistribution of platinum and arsenic atoms after Ni(Pt) silicidation of As-doped polycrystalline Si. These measurements were performed on a field-effect transistor and compared with those obtained in unpatterned region submitted to the same process. These results suggest that Pt and As redistribution during silicide formation is only marginally influenced by the confinement in microelectronic devices. On the contrary, there is a clear difference with the redistribution reported in the literature for the blanket wafers. Selective etching used to remove the non-reacted Ni(Pt) film after the first rapid heat treatment may induce this difference. © 2011 American Institute of Physics.

Impact of high-k dielectrics on breakdown performances of SiC and diamond Schottky diodes

This paper presents a comparison between SiC and diamond Schottky barrier diodes using the oxide ramp termination. The influences of the dielectric thickness and relative permittivity on the diode's electrical performance are investigated. Typical commercial drift layer parameters are used for this study. The extension of the space charge area throughout the drift region and the current distribution at breakdown are shown. The efficiency of the termination is also evaluated for both SiC and diamond diodes. © (2009) Trans Tech Publications, Switzerland.

Bacterial growth rate and host factors as determinants of intracellular bacterial distributions in systemic Salmonella enterica infections.

Bacteria of the species Salmonella enterica cause a range of life-threatening diseases in humans and animals worldwide. The within-host quantitative, spatial, and temporal dynamics of S. enterica interactions are key to understanding how immunity acts on these infections and how bacteria evade immune surveillance. In this study, we test hypotheses generated from mathematical models of in vivo dynamics of Salmonella infections with experimental observation of bacteria at the single-cell level in infected mouse organs to improve our understanding of the dynamic interactions between host and bacterial mechanisms that determine net growth rates of S. enterica within the host. We show that both bacterial and host factors determine the numerical distributions of bacteria within host cells and thus the level of dispersiveness of the infection.

Angular distribution of field emitted electrons from vertically aligned carbon nanotube arrays

Angular field emission (FE) properties of vertically aligned carbon nanotube arrays have been measured on samples grown by plasma enhanced chemical vapor deposition and characterized by scanning electron microscope and I-V measurements. These properties determine the angular divergence of electron beams, a crucial parameter in order to obtain high brilliance FE based cathodes. From angular distributions of the electron beam transmitted through extraction grids of different mesh size and by using ray-tracing simulations, the maximum emission angle from carbon nanotube tips has been determined to be about ± 30 around the tube main axis. © 2012 American Institute of Physics.