1,720,963 research outputs found
Passivity of TaSiN Barrier Layer on Thermochromic Vanadium Dioxide Thin Films
No full textAmorphous TaSiN is a well-known oxidation and diffusion barrier layer for microelectronic devices fabricated to operate in harsh environments. TaSiN is traditionally used as part of the metallization scheme to shield contacts and interconnects from extreme environments and inter-layer diffusion. In this project, we studied the passivity of TaSiN - VO2 interface and the anti-reflective characteristic of TaSiN cap layer. Different layers geometry investigated on fussed quartz substrates(Q) include: (i) Q\VO2, (ii) Q\ VO2\TaSiN, (iii) Q\TaSiN\ VO2 and (iv) Q\TaSiN\ VO2\TaSiN. All the layers were deposited by magnetron sputtering method. The VO2 layer was prepared by sputtering pure vanadium target and subsequently oxidizing the layer at 500°C, 800 mtorr pressure for 4 hours. TaSiN layers were deposited by reactive sputtering of pure TaSi2 target in argon and nitrogen gas mixture at room temperature. VO2 thermochromic transition were observed optically and electrically and studied to see the effect of TaSiN on the property. Transmittance and sheet resistivity of VO2 were not adversely affected by the presence of TaSiN layers. Though the transition temperature shifted slightly to higher temperatures for sandwiched VO2 layer, the transition characteristics is not degraded. Transparent TaSiN is showing promise as a passive and protective layer for opto-electronic devices
Composite Contact Metallization on SiC for High Temperature Applications in Air
Full text linkComposite ohmic and Schottky contacts fabricated on 4H-SiC for applications in air at 350^oC are described and evaluated in this study. The ohmic contacts were fabricated on p+ implanted and n+ epitaxial materials, while the Schottky contacts were on n- epilayers.
These contacts were protected from the harsh environment with the following metallization layers: Ta-Si-N served as diffusion/oxidation barrier, Pt-N sputter-deposited at 250^oC promoted adhesion between the diffusion barrier layer and the AAu cap layer and it also act as barrier to Au diffusion. A gold cap layer was deposited for the purpose of wirebonding to the device or die attach to a carrier.
The composite contact's electrical and physical characteristics were monitored as a function of annealing time in air at 350^oC. For the ohmic contact, characteristics such as the specific contact resistance and SiC sheet resistance determined from TLM measurements were monitored with time of anneal. Contact parameters of nickel ohmic contact on heavily implanted p+ 4H-SiC materials were very stable up to 4000 hours at 350^oC in air. 70-30 wt% Al-Ti ohmic contacts on implanted p+, 80-20 wt% Ni-Cr and Ni ohmic contacts on epitaxial n+ 4H-SiC were also studied.
Current density - voltage and capacitance - voltage characteristics of nickel silicide and Ta-Si-N Schottky contacts were studied as a function of annealing time in air. Parameters such as the barrier height and ideality factor of the devices were monitored and found to be stable as the devices were annealed in air.
Adhesion characteristics of the metallization stack (barrier layer, Pt layer and Au layer) on thermal oxides, Schottky contacts and ohmic contacts were investigated in this study. All the contacts have good adhesion to the metallization as fabricated except for the nickel ohmic contacts that needed Ar ion cleaning to improve its adhesion to the metallization stack.
In all cases, inter-diffusion within the metallization and oxidation of the contacts were monitored with RBS (Rutherford backscattering spectrometery) and AES (Auger electron spectroscopy)
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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