Local crystallographic texture and voiding in passivated copper interconnects

A correlation between local crystallographic texture and stress‐induced void formation in tantalum‐encapsulated, copper interconnects was revealed by electron backscattering diffraction studies in a scanning electron microscope. Lines exhibiting an overall stronger 〈111〉 texture showed better resistance to void formation. Furthermore, grains adjacent to voids exhibited weaker 〈111〉 texture than grains in unvoided regions of the same line. The locally weaker 〈111〉 texture at voided locations suggests the presence of higher diffusivity, twist boundaries. This work, which represents the first characterization of local texture in stress voided, copper lines, helps to elucidate the relative importance of the thermodynamic and kinetic factors which govern void formation and growth. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70319/2/APPLAB-69-26-4017-1.pd

Modeling the Dietary Pesticide Exposures of Young Children

A stepped approach was used to assess the exposures of 1 1/2 – 4 1/2-year-old children in the United Kingdom to residues of pesticides (dithiocarbamates; phosmet; carbendazim) found in apples and pears. The theoretical possibility that the acute reference dose (ARD) was being exceeded for a particular pesticide/fruit was tested by applying a combination of maximal variability and maximum measured residue relative to an average-body-weight consumer. The actual risk was then quantified by stochastically modeling consumption, from dietary survey data, with individual body weights, against published residue results for 2000–2002 and the variability of residue distribution within batches. The results, expressed as numbers of children per day likely to ingest more than the ARD, were in the range of 10–226.6 children per day, depending upon the pesticide and year of sampling. The implications for regulatory action are discussed

CoWBP capping barrier layer for sub 90 nm Cu interconnects

Abstract Electroless cobalt films have been obtained by deposition using a plating bath containing two reducing agents: dimethylamineborane (DMAB) and sodium hypophosphite. This formulation allows spontaneous activation on copper followed by auto catalytic electroless plating. CoWBP and CoBP films are proposed as diffusion barriers and encapsulation layers, for copper lines and via contacts for ULSI interconnect applications. The crystalline structure, chemical composition and oxidation states of the elements were studied, as well as the electrical resistivity, topography and morphology of the films. The film composition was characterized as a function of the solution composition; the barrier properties of the films were tested and an oxidation resistance study was conducted. The films were characterized and the results show that they can be applied as capping layers for ULSI copper metallization

Transformación de exámenes de ambientes e-learning en videojuegos web

El objetivo de este trabajo es presentar un modelo para la creación de juegos educativos como metáforas representativas de las interfaces de la herramienta de examen utilizada en un eco-sistema de e-learning. Las plataformas de e-learning se componen de Objetos de Aprendizaje que los educadores pueden crear utilizando herramientas de software. Controlando estos objetos es posible establecer métodos de evaluación lúdicos para los estudiantes.XIII Workshop Tecnología Informática Aplicada en Educación (WTIAE).Red de Universidades con Carreras en Informática (RedUNCI

Transformación de exámenes de ambientes e-learning en videojuegos web

El objetivo de este trabajo es presentar un modelo para la creación de juegos educativos como metáforas representativas de las interfaces de la herramienta de examen utilizada en un eco-sistema de e-learning. Las plataformas de e-learning se componen de Objetos de Aprendizaje que los educadores pueden crear utilizando herramientas de software. Controlando estos objetos es posible establecer métodos de evaluación lúdicos para los estudiantes.XIII Workshop Tecnología Informática Aplicada en Educación (WTIAE).Red de Universidades con Carreras en Informática (RedUNCI

The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry

Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes

A crystallographic study of the structure of some antibiotics

The crystal structure of 6-aminopenicillanic acid (C8, H12, N2, O3, S) (I) and cephalosporin Cc (C14, H17, O6, N3, S; CH3CO2H), (II) have been determined by X-ray crystallographic analysis. 6-aminopenicillanic acid crystallises in flat orthorhombic plates, Crystal data. a = 6.24 ± .02 Å, b = 14.83 ± .04 Å, c = 10.49 ± .03Å space group P212121 Z=4. Using copper Kα radiation layers okl - 4kl and hkO to hk8 were recorded on equi-inclination Wissenberg photographs. A total of 988 reflections were measured visually out of a possible 1170 in the copper sphere. A Patterson function was calculated using data sharpened by the finction 1⁄f2 exp.(3 Sin2θ), where f was the scattering factor for carbon; from this a superposition function was calculated. It was possible to obtain all atomic positions from this. These were refined using anistropic and isotropic least squares procedures, the final positions have calculated deviations of about .01Å. The final agreement factor was 11.6% using isotropic and 9.7%, anistropic temperature factors. The structure is similar to that reported by Crowfoot, Bunn, Rogers-Low and Turner-Jones for potassium benzyl penicillin except that in the thiazolidine ring the atom out of the plane of the other four is the nitrogen instead of the carbon to which the carboxyl group is attached, as in the other penicillins. The bond between the sulphur and the gem-dimethyl group is longer in all the penicillins than the generally accepted value for a C - S single bond (1.86 Å compared with 1.81 - 1.82 Å). The length of the C - N bond in the β-lactam group falls between that of a C - N single bond and that of an ordinary C - N peptide bond; this is probably caused by the lack of resonance in the fused β-lactam ring. Cephalosporin Cc crystalises in flat orthorhombic needles (a = 5.04 ± .0 Å, b = 7.00 ± .02 Å, c = 54.6 ± .2 Å), space group P212121. 1521 Reflections out of a possible 2580 in the copper sphere were measured visually on equi-inclination Wissenberg films (layers okl - 3kl and hol - h51). The structure was determined and refined in a similar fashion to 6-aminopenicillanic acid, though because of the larger size of the molecule three rounds of Fourier refinement were needed before it was possible to use the least square procedure. The final agreement after eight rounds of least squares refinement was 10.6%, with calculated standard deviations of about .01 Å. The structure was identical to that proposed by Abraham and Newton. The bond distances were all within the expected range of values. The α-amino group of the side chain together with the acetic acid of crystallisation formed a hydrogen bond system around the screw axis parallel to b. There was no significant difference between the lengths bonds of the β-lactam group in cephalosporin Cc and in 6-aminopenicillanic acid. [For the diagrams to accompany this abstract, please consult the PDF.]</p