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Edge Shape (edge + shape)
Selected AbstractsAverage power-handling capability of the signal line in coplanar waveguides on polyimide and GaAs substrates including the irregular line edge shape effectsINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2005Wen-Yan Yin Abstract The average power-handling capability (APHC) of the signal line in finite-ground coplanar waveguides (FGCPWs) on polyimide and GaAs substrates is evaluated in this paper. In our approach, the ohmic loss of metal lines is characterized in different ways, and the effects of an irregular edge shape are also considered. The rise in temperature of the signal line is determined by single- and double-layer thermal models, with the temperature-dependent properties of the thermal conductivity of GaAs material treated appropriately. Parametric studies are carried out to investigate the overall effects of signal-line width, thickness, conductivity, edge-shape angle, and polyimide thickness on APHC. Some possible ways to enhance the APHC of these FGCPWs are also proposed. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [source] Monitoring roughness and edge shape on semiconductors through multiresolution and multivariate image analysisAICHE JOURNAL, Issue 5 2009Pierantonio Facco Abstract Photolithography is one of the most important processes in the production of integrated circuits. Usually, attentive inspections are required after this process, but are limited to the measurement of some physical parameters such as the critical dimension and the line edge roughness. In this paper, a novel multiresolution multivariate technique is presented to identify the abnormalities on the surface of a photolithographed device and the location of defects in a sensitive fashion by comparing it to a reference optimum, and generating fast, meaningful and reliable information. After analyzing the semiconductor surface image in different levels of resolutions via wavelet decomposition, the application of multivariate statistical monitoring tools allows the in-depth examination of the imprinted features of the product. A two level nested PCA model is used for surface roughness monitoring, while a new strategy based on "spatial moving window" PCA is proposed to analyze the shape of the patterned surface. The effectiveness of the proposed approach is tested in the case of semiconductor surface SEM images after the photolithography process. The approach is general and can be applied also to inspect a product through different types of images, different phases of the same production systems, or different processes. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] X-ray absorption spectroscopic studies on model compounds for biological iodine and bromineJOURNAL OF SYNCHROTRON RADIATION, Issue 1 2005Martin C. Feiters X-ray absorption spectra of a number of organic iodine and bromine compounds of biological relevance, as well as of a series of iodine compounds with different oxidation states, have been measured. The iodine K -edge spectra (XANES) are found to be relatively featureless but the position of the edge is found to be sensitive to formal valence (among other factors), and the edge shape to the number of bound O atoms. EXAFS spectra of organohalogen compounds (both iodine and bromine) can be used to discriminate between aliphatic and aromatic compounds. There are differences both in the distances from the halogens to the first shell of C atoms, which are shorter for aromatic compounds, and in the patterns of shells in the Fourier transforms. This result is expected to be relevant to studies at these edges in biological systems. [source] Peculiar band gap structure of graphene nanoribbonsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 2 2007Motohiko Ezawa Abstract Graphene nanoribbons are quasi-one-dimensional meterials with finite width. Characterizing a wide class of nanoribbons by edge shape and width, we make a systematic analysis of their electronic properties. The band gap structure of nanoribbons is shown to exhibit a valley structure with stream-like sequences of metallic or almost metallic nanoribbons. Among them, all zigzag nanoribbons are metallic, and armchair nanoribbons are metallic by period of 3. We find that these stream-like sequences correspond to equi-width curves, and that the band gap of chiral and armchair nanoribbons oscillate as a function of the width. Furthermore a possible application of nanoribbons to nanoelectronics is discussed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A neck-in model in extrusion lamination processPOLYMER ENGINEERING & SCIENCE, Issue 1 2010Seiji Shiromoto In this study, the experiment of the extrusion lamination process using high-pressure process low-density polyethylene (LDPE) was performed. The nonisothermal viscoelastic simulation of the extrusion lamination experiment was also carried out. The simulation results were in good agreement with the experimental data within wide range of take up velocity and air gap length. We developed the theoretical model based on force balance and deformation type of a film to predict the neck-in behavior in the extrusion lamination or cast film process. It was suggested from the neck-in model that the neck-in correlates with the ratio of planar to uniaxial elongational viscosity. It was confirmed that the neck-in model could predict the film edge shape and neck-in properly for conventional LDPE. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers [source] | ||||||||||