Modeling of the Reservoir Effect on Electromigration Lifetime

Electromigration behaviour in W-plug/metal stripe structures is different from conventional metal-strip structures because there is a blocking boundary formed by the immobile W-plug in the contact/via. Electromigration failures occur more readily close to the W-plug than in metal-strip structures because metal ions are forced away from the contacts/vias by electric current, blocking the contacts/vias area. Several works have reported electromigration lifetime of multiple level interconnects to be influenced by the presence of a reservoir around the contacts/vias. Reservoirs are metal parts that are not or are hardly conducting current that act as a source to provide atoms for the area around the blocking boundary where the atoms migrate away due to the electric current. Interconnect lifetime can be prolonged by using the reservoirs, called the ¿reservoir effect¿. 2D simulation of the effects of reservoirs has been performed. The stress build-up during electromigration in the contact area can be simulated for several configurations, separating the effects of overlap, total reservoir area, the reservoir layout directions (vertical and horizontal), number of contacts/vias and contact/via placement. It is very useful for IC design rules to estimate which parameters are important for IC reliability. In this study, we considered the critical stress that the metal line can sustain before void formation as failure criterion. The failure time is determined by the time to reach the critical stres

High-Performance Deep SubMicron CMOS Technologies with Polycrystalline-SiGe Gates

The use of polycrystalline SiGe as the gate material for deep submicron CMOS has been investigated. A complete compatibility to standard CMOS processing is demonstrated when polycrystalline Si is substituted with SiGe (for Ge fractions below 0.5) to form the gate electrode of the transistors. Performance improvements are achieved for PMOS transistors by careful optimization of both transistor channel profile and p-type gate workfunction, the latter by changing Ge mole fraction in the gate. For the 0.18 ¿m CMOS generation we record up to 20% increase in the current drive, a 10% increase in the channel transconductance and subthreshold swing improvement from 82 mV/dec to 75 mV/dec resulting in excellent ¿on¿/¿off¿ currents ratio. At the same time, NMOS transistor performance is not affected by gate material substitutio

Nanotextured Superhydrophobic Electrodes Enable Detection of Attomolar-Scale DNA Concentration within a Droplet by Non-Faradaic Impedance Spectroscopy

Label-free, rapid detection of biomolecules in microliter volumes of highly diluted solutions (subfemtomolar) is of essential importance for numerous applications in medical diagnostics, food safety, and chem-bio sensing for homeland security. At ultra-low concentrations, regardless of the sensitivity of the detection approach, the sensor response time is limited by physical diffusion of molecules towards the sensor surface.We have developed a fast, low cost, non-faradaic impedance sensing method for detection of synthetic DNA molecules in DI water at attomolar levels by beating the diffusion limit through evaporation of a micro-liter droplet of DNA on a nanotextured superhydrophobic electrode array. Continuous monitoring of the impedance of individual droplets as a function of evaporation time is exploited to dramatically improve the sensitivity and robustness of detection. Formation of the nanostructures on the electrode surface not only increases the surface hydrophobicity, but also allows robust pinning of the droplet contact area to the sensor surface. These two features are critical for performing highly stable impedance measurements as the droplet evaporates. Using this scheme, the detection limit of conventional non-faradaic methods is improved by five orders of magnitude. The proposed platform represents a step-forward towards realization of ultra-sensitive lab-on-chip biomolecule detectors for real time point-of-care application. Further works are however needed to ultimately realize the full potential of the proposed approach to appraise biological samples in complex buffer solutions rather than in DI water

Cardiac Manifestations from Non-FIP1L1-PDGFRα-Associated Hypereosinophilic Syndrome in a 13-Year-Old African American Boy

Hypereosinophilic syndrome (HES) is a rare disorder typically seen in males, aged 20 to 50, with a predisposition for Caucasians. It is marked by overproduction of eosinophils (>1,500/μL) and multiorgan system damage due to eosinophilic infiltration and mediator release. There are multiple variants of HES. Cardiac complications are more common in myeloproliferative HES associated with the FIP1L1-PDGFRα mutation. Sequelae range from acute necrosis and thrombus formation to fibrosis of the endomyocardium. We describe a young boy who presented with chest pain and dyspnea. A diagnosis of HES was made after all other etiologies of eosinophilia were excluded. Although he was found to be negative for the FIP1L1-PDGFRα mutation, his cardiac complications included pericardial effusion and restrictive cardiomyopathy, without myocardial necrosis. Multi-organ involvement resulted in pericarditis, pleuritis, nephritis, and dermatitis. In this paper, we review his case and discuss the known subtypes of HES, the classic cardiac complications, and available treatment strategies

Governance and Management Systems in Mediterranean Marine and Coastal Biosphere Reserves

Recent studies in UNESCO World Heritage sites and Biosphere Reserves (BRs) identified gaps regarding the effectiveness of planning, governance, and management. The objective of a study carried out is to develop innovative approaches of evidence-based governance in UNESCO-designated marine protected areas in the Mediterranean Basin. Three different types of Biosphere Reserves have been selected for the present chapter: the Tuscan Islands Archipelago in Italy; the Terres de l'Ebre Delta in Spain; and the marine and coastal area of Gouraya in Algeria. Current and future evidence in the BRs differ and require actions related to the local realities and challenges. The Terres de l'Ebre BR is step by step implementing the new strategies and processes. The Tuscan Island BR has already prepared the frameworks and participatory instruments which await implementation. The Gouraya BR through the National Park established conservation and development functions, but for its realization it still seeks an increase of awareness and commitments of the authorities as well as management tools and funds. The "evidence-based governance and management system" is considered an integrated approach adequately involving the three dimensions top-down, bottom-up, and outside-in. It is an instrument to improve effectiveness of management and to involve the local communities and stakeholders in the decision processes in Biosphere Reserves