170,167 research outputs found
Electrical characterization of the TiN/Ti/n+/Si (and p+/Si) interfaces by means of a circular resistor test structure
No full textA circular geometry based test structure for contact resistance measurements is introduced, together with a compact analytical model for contact resistivity extraction. The Circular Resistor (CR) structure is intended to be used for VLSI contacts that tend to a rounded shape due to lithographic effects
Ohmic contact electromigration
No full textIn this paper ohnfic contact electromigration is briefly reviewed. After a short introduction on the main contact failure mechanisms and technological solutions, the effect of contact scaling on electromigration is considered. Then, guidelines on test structures and lifetest set-up for contact electromigration studies are given, with particular reference to the thermal characterization needed to extract rehable data from lifetest experiments. Finally, the most recent experimental results obtained with both aluminum based metallizations and contacts making use of silicides or barrier layers are reviewed and compared
On the validity of resistometric technique in electromigration studies of narrow stripes
No full textIn the framework of the development of a submicron CMOS technology, we investigate the reliability of Al stripes 1.5-8 micron wide and compared the results obtained with various techniques; in particular in this paper the resistometric method is compared with the standard MYF technique for the narrowest stripes
The Italian Competition Authority starts an investigation into the national consortium for the recovery and recycling of cellulose-based packaging for alleged infringement of Art. 101 TFEU
No full textThe Al-1% Si/TiN/Ti interconnection scheme: electromigration and reliability extrapolation
No full textThe electromigration performance of Al-1%Si/TiN/ti metal scheme is investigated both for contacts and for stripes and compared with the results for the standard Al-1%Si metallization
Electromigration in thin-film interconnection lines: models, methods and results
No full textElectromigration /EM) in thin film interconnection lines is one of the major concerns for the development of ULSI devices, employing advanced design rules. Different models have been proposed, but the complete comprehension of the basic physical mechanisms leading to EM is still unsatisfactory. In this work, well-established results and unsolved problems are reviewed
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
Test Structures for Electromigration Evaluation in Submicron Technology
No full textElectromigration tests have been performed on a number of test structures with different geometries and microstructures, highlighting the limits of each test structure in relation with the technologies employed in submicron interconnections. A new set of test structures based on the single level stripe, the multilevel Kelvin contact and via chain structures, are then proposed to investigate electromigration in submicron technology devices. The new test structures are envisaged to overcome the problems which have previously been associated with conventional ASTM test structures. The use of a multifinger Babel Tower structure ensures that the microstructure of the end segment is consistent with the test stripe and the use of tungsten via plugs in multilevel systems eliminates the reservoir effect. These modifications will allow the reliability of the interconnections to be evaluated in a manner which is representative of actual ULSI device structures. As submicron lines are not the critical element of an IC metallisation, an additional set of test structures using a larger linewidth was designed to enable a comparison between bamboo and multigrain structures
Design-code traceability for object- oriented systems
No full textTraceability is a key issue to ensure consistency among software artifacts of subsequent phases of the development cycle. However, few works have so far addressed the theme of tracing object oriented (OO) design into its implementation and evolving it. This paper presents an approach to checking the compliance of OO design with respect to source code and support its evolution. The process works on design artifacts expressed in the OMT (Object Modeling Technique) notation and accepts C++ source code. It recovers an ‘as is’ design from the code, compares recovered design with the actual design and helps the user to deal with inconsistencies. The recovery process exploits the edit distance computation and the maximum match algorithm to determine traceability links between design and code. The output is a similarity measure associated to design-code class pairs, which can be classified as matched and unmatched by means of a maximum likelihood threshold. A graphic display of the design with different green levels associated to different levels of match and red for the unmatched classes, is provided as a support to update the design and improve its traceability to the cod
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
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