1,725,196 research outputs found
3D system integration on 300 mm wafer level
No full textS.20-25The copper electrochemical deposition (Cu-ECD) filling capability of high aspect ratio through silicon vias (HAR-TSVs) and homogeneity over 300 mm wafers were investigated on a film stack of thermal ALD (thALD) TaxNy barrier with thermal ALD Ru seed in comparison to TixNy barrier with a standard Cu i-PVD seed layer using a commercial 300 mm plating tool. As a first step, Cu-ECD was conducted on wafers with TSV blind holes with aspect ratios (AR) of 10 to 12. To achieve this, a thermal ALD film stack of approximately 6 nm TaxNy and 9 nm Ru (with a sheet resistance of [25.6 ± 1.4] O/y) were deposited at 250 °C. The reactants for the barrier layer were (tert-butylimido)tris(diethylamino)tantalum(V) (TBTDET) and ammonia (NH3) as co-reactant. For the Ru seed layer deposition (ethylcyclopentadienyl)(pyrrolyl)ruthenium(II) (ECPR) and molecular oxygen as co-reactant were used supplemented by a hydrogen purge step after every third ALD cycle. The corresponding ALD growth was observed during the entire process by in-situ real-time spectroscopic ellipsometry (irtSE). Blister-free deposition and satisfactory film stack adhesion with no delamination was verified ex situ by scanning electron microscopy (SEM). The deposited copper inside the TSVs was analyzed by focused ion beam (FIB) imaging and X-ray tomography. The Cu ECD filling capability in HAR-TSVs was shown on a film stack of thALD TaxNy thALD Ru seed using a commercial industry standard 300 mm plating tool. A novel blister-free ultra-thin Ru ALD film having good adhesion properties and unique advantages, e. g. high conformity in high-aspect-ratio through-silicon vias large-scale film uniformity over 300 mm wafers, as well as good reproducibility was developed.20
An ultra-low noise capacitance to voltage converter for sensor applications in 0.35  µm CMOS
No full textS.285-301In this paper we present a readout circuit for capacitive micro-electro-mechanical system (MEMS) sensors such as accelerometers, gyroscopes or pressure sensors. A flexible interface allows connection of a wide range of types of sensing elements. The ASIC (application-specific integrated circuit) was designed with a focus on ultra-low noise operation and high analog measurement performance. Theoretical considerations on system noise are presented which lead to design requirements affecting the reachable overall measurement performance. Special emphasis is put on the design of the fully differential operational amplifiers, as these have the dominant influence on the achievable overall performance. The measured input referred noise is below 50 zF/Hz within a bandwidth of 10 Hz to 10 kHz. Four adjustable gain settings allow the adaption to measurement ranges from ±750 fF to ±3 pF. This ensures compatibility with a wide range of sensor applications. The full input signal bandwidth ranges from 0 Hz to more than 50 kHz. A high-precision accelerometer system was built from the described ASIC and a high-sensitivity, low-noise sensor MEMS. The design of the MEMS is outlined and the overall system performance, which yields a combined noise floor of 200 ng/Hz, is demonstrated. Finally, we show an application using the ASIC together with a CMOS integrated capacitive pressure sensor, which yields a measurement signal-to-noise ratio (SNR) of more than 100 dB.6Nr.
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Draft Genome Sequence of Acetobacterium bakii DSM 8239, a Potential Psychrophilic Chemical Producer through Syngas Fermentation
No full textAcetobacterium bakii DSM 8239 is an anaerobic, psychrophilic, and chemolithoautotrophic bacterium that is a potential platform for producing commodity chemicals from syngas fermentation. We report here the draft genome sequence of A. bakii DSM 8239 (4.14 Mb) to elucidate its physiological and metabolic properties related to syngas fermentation.
Variations on the Author
No full text“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
No full textWe 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
No full textWe 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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