1,721,032 research outputs found
Low leakage and high performance of nMOSFET using SiGe layer as a diffusion barrier
No full textAs a boron diffusion barrier, a 20 nm-thick Si0.8Ge0.2 layer was successfully utilized in n-channel MOSFETs for implementing a retrograded well structure. Compared with the conventional Si CMOS process, the developed n-channel MOSFFT process provides an enhanced transconductance (7%) and lower sub-threshold swing which is nearly unchanged even at an increased drain-source voltage. Especially, because sub-threshold leakage current is one of the key issues in the MOS device scaling due to reduced threshold voltage, the usage of a Si0.8Ge0.2 layer in n-channel MOSFET was verified to be useful for low power and high performance even under aggressive scaling constraints. (C) 2004 Elsevier Ltd. All rights reserved.This work was supported by NRL (National Research
Laboratory) Program under Grant No. M1-0302-00-
0050 of KISTEP organized by the Ministry of Science
and Technology, Korea
Strained-SiGe complementary MOSFETs adopting different thicknesses of silicon cap layers for low power and high performance applications
No full textWe introduce a strained-SiGe technology adopting different thicknesses of Si cap layers towards low power and high performance CMOS applications. By simply adopting 3 and 7 nm thick Si-cap layers in n-channel and p-channel MOSFETs, respectively, the transconductances and driving currents of both devices were enhanced by 7 to 37% and 6 to 72%. These improvements seemed responsible for the formation of a lightly doped retrograde high-electron-mobility Si surface channel in nMOSFETs and a compressively strained high-hole-mobility Si0.8Ge0.2 buried channel in pMOSFETs. In addition, the nMOSFET exhibited greatly reduced subthreshold swing values (that is, reduced standby power consumption), and the pMOSFET revealed greatly suppressed IN noise and gate-leakage levels. Unlike the conventional strained-Si CMOS employing a relatively thick (typically > 2 mu m) SixGe1-x, relaxed buffer layer, the strained-SiGe CMOS with a very thin (20 nm) Si0.8Ge0.2 layer in this study showed a negligible self-heating problem. Consequently, the proposed strained-SiGe CMOS design structure should be a good candidate for low power and high performance digital/analog applications
Significance of gate oxide thinning below 1.5 nm on 1/f noise behavior in n-channel metal-oxide-semiconductor field-effect transistors under electrical stress
No full textThe purpose of this study is to investigate the effects of electrical stress on the 1/f noise behavior in n-channel metal-oxide-semiconductor transistors with ultrathin gate oxides. Even under a weak electrical stress, the drain current noise (S-id) of the device with a 1.4-nm-thick oxide was found to increase abruptly beyond a certain critical gate bias. This deteriorated noise property was proven to be from simultaneous increases in gate current noise (S-ig) and the correlation between Sid and S-ig which were directly related to oxide trap generation and gate/drain current (I-g/(d)) ratio, respectively. Meanwhile, the increase in Sid in the device with a 2.3-nm-thick oxide after stress, with a comparable transconductance degradation, was relatively insignificant because of the device's smaller I-g/I-d ratio, even if the measured S-ig was comparable to that of the thinner oxide device. Consequently, the 1/f noise degradation could be much more significant than the accompanying DC characteristic degradations in the thin gate oxide below 1.5 nm
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Performance improvements of forward handover based on path rerouting and extension in wireless ATM
No full textTo support efficiently the high-speed service and the multimedia service in mobile communication environments, network architecture is generally based on small cell radius structure to increase the wireless channel capacity. In a small cell radius structure based mobile network environment, a mobile station with large mobility should perform frequent handover. Thus, advanced handover mechanism should be provided, and must be done fastly. For these reasons, we suggest the efficient handover mechanism based on forward handover method in this paper. Proposed handover mechanism could support fast handover procedure, and is performed by using optimized path. Also, proposed handover mechanism could support QoS (Quality of Service) attribute of multimedia traffic during handover procedure. We evaluated the performance of proposed handover mechanism, and analysis results show that the suggested forward handover mechanism has less blocking ratio and lower delay than conventional backward handover mechanism.
Effect of sodium butyrate on the production, heterogeneity and biological activity of human thrombopoietin by recombinant Chinese hamster ovary cells
No full textHuman thrombopoietin (hTPO) is a heavily glycosylated protein with 6 and 24 potential N- and O-glycosylation sites, respectively. To determine the effect of sodium butyrate (NaBu) on the production and quality of hTPO in recombinant Chinese hamster ovary (rCHO) cells, NaBu (0-10 mM) was added to the cultures of exponentially growing cells. NaBu addition significantly increased both the specific and volumetric hTPO production, although it decreased the cell viability by apoptosis in a dose-dependent manner. The highest hTPO concentration of 82.2 +/- 5.6 mug ml(-1) was obtained in the culture with 3 mM NaBu addition. Compared with the culture without NaBu addition, the culture with 3 mM NaBu resulted in a 6.4-fold increase in q(TPO) and a 3.3-fold increase in the final hTPO concentration on day 7. However, NaBu deteriorated the quality of hTPO, resulting from increased heterogeneity, reduced acidic hTPO isoforms, reduced alpha(2 --> 3) sialylation, and decreased in vivo biological activity. We also found that the biological activity of hTPO in the culture with 3 mM NaBu addition collected on day 7 was 72% of that in the culture without NaBu addition. Taken together, the use of NaBu or its optimal concentration for high-level expression of a heavily glycosylated protein like hTPO should be determined by considering its detrimental effect on the quality of glycoprotein. (C) 2004 Elsevier B.V. All rights reserved
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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