441 research outputs found

    Metal contacts to lowly doped Si and ultra thin SOI

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    We present our investigations on the fabrication of ohmic and Schottky contacts of several metals on lowly doped bulk Si and SOI wafers. Through this paper we evaluate the fabrication of rectifying devices in which no doping is intentionally introduced

    Fabrication and characterization of the charge-plasma diode

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    We present a new lateral Schottky-based rectifier called the charge-plasma diode realized on ultrathin silicon-oninsulator. The device utilizes the workfunction difference between two metal contacts, palladium and erbium, and the silicon body. We demonstrate that the proposed device provides a low and constant reverse leakage-current density of about 1 fA/μm with ON/OFF current ratios of around 107 at 1-V forward bias and room temperature. In the forward mode, a current swing of 88 mV/dec is obtained, which is reduced to 68 mV/dec by back-gate biasing

    Effect of Thermal Gradients on the Electromigration Lifetime in Power Electronics

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    The combined effects of electromigration and thermomigration are studied. Significantly shorter electromigration lifetimes are observed in the presence of a temperature gradient. This cannot be explained by thermomigration only, but is attributed to the effect of temperature gradient on electromigration-induced failures

    Low Stressed In-situ Boron doped Poly SiGe Layers for High-Q Resonators

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    Polycrystalline silicon-germanium (Poly SixGe1-x) can be used as one of the microstructural materials for MEMS due to its superior mechanical properties [1,2], high quality factor [3] and low thermal budget requirements based on the Ge contents [4] (<450 oC) for post processing on top of CMOS chip. This work deals with the characterization of in-situ boron doped poly SiGe layers LPCVD deposited at 430 oC with a mixture of 0.2% diborane (B2H6) in Argon on 110 nm SiO2. The concerned properties like sheet resistance and residual stress in the deposited layers are investigated at diborane mixture flow of 50 sccm and 100 sccm. It is observed that the deposition rate is decreased with the increase of B2H6 mixture flow. Whereas, the resistivity of these deposited layers decrease linearly with the increase of B2H6 mixture flow. The stress in the deposited layers shows a trend from low tensile to low compressive with the increase of diborane mixture flow. The properties of the layers deposited at 50 sccm of diborane mixture flow shows good results in terms of resistivity, deposition rate, cross load thickness uniformity and residual stress and therefore qualify them to use as structural layers for the realization of disk resonator

    Nkx2-5 and Sarcospan genetically interact in the development of the muscular ventricular septum of the heart

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    The muscular ventricular septum separates the flow of oxygenated and de-oxygenated blood in air-breathing vertebrates. Defects within it, termed muscular ventricular septal defects (VSDs), are common, yet less is known about how they arise than rarer heart defects. Mutations of the cardiac transcription factor NKX2-5 cause cardiac malformations, including muscular VSDs. We describe here a genetic interaction between Nkx2-5 and Sarcospan (Sspn) that affects the risk of muscular VSD in mice. Sspn encodes a protein in the dystrophin-glycoprotein complex. Sspn knockout (Sspn(KO)) mice do not have heart defects, but Nkx2-5(+/−)/Sspn(KO) mutants have a higher incidence of muscular VSD than Nkx2-5(+/−) mice. Myofibers in the ventricular septum follow a stereotypical pattern that is disrupted around a muscular VSD. Subendocardial myofibers normally run in parallel along the left ventricular outflow tract, but in the Nkx2-5(+/−)/Sspn(KO) mutant they commonly deviate into the septum even in the absence of a muscular VSD. Thus, Nkx2-5 and Sspn act in a pathway that affects the alignment of myofibers during the development of the ventricular septum. The malalignment may be a consequence of a defect in the coalescence of trabeculae into the developing ventricular septum, which has been hypothesized to be the mechanistic basis of muscular VSDs

    Validatie van het nutriënten-emissiemodel STONE met meetgegevens uit het Landelijk Meetnet effecten Mestbeleid (LMM) en de Landelijke Steekproef Kaarteenheden (LSK)

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    De uitkomsten van het model STONE zijn gevalideerd op gemeten concentraties in drains en grondwater uit LMM (Landelijk Meetnet effecten Mestbeleid) en gemeten fosfaatophoping volgens LSK (Landelijke Steekproef Kaarteenheden). Voor de validatie is gebruik gemaakt van een in 2008 ontwikkeld protocol. Uit de validatie komt naar voren dat op nationale schaal de gemiddelde door STONE gesimuleerde nitraatconcentraties in grondwater en drainwater goed overeenkomen met de metingen. De gesimuleerde DOC-concentraties in grondwater en drainwater en de fosfaatconcentraties in het grondwater wijken sterker af van de metingen. Tevens bleek uit de validatie op LSK dat de verdeling van P over boven- en ondergrond afwijkt van de metingen. Voor deze stoffen is dus een verdere verbetering van het model en/of de parameterisatie gewenst

    A novel approach to sequence validating protein expression clones with automated decision making

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    <p>Abstract</p> <p>Background</p> <p>Whereas the molecular assembly of protein expression clones is readily automated and routinely accomplished in high throughput, sequence verification of these clones is still largely performed manually, an arduous and time consuming process. The ultimate goal of validation is to determine if a given plasmid clone matches its reference sequence sufficiently to be "acceptable" for use in protein expression experiments. Given the accelerating increase in availability of tens of thousands of unverified clones, there is a strong demand for rapid, efficient and accurate software that automates clone validation.</p> <p>Results</p> <p>We have developed an Automated Clone Evaluation (ACE) system – the first comprehensive, multi-platform, web-based plasmid sequence verification software package. ACE automates the clone verification process by defining each clone sequence as a list of multidimensional discrepancy objects, each describing a difference between the clone and its expected sequence including the resulting polypeptide consequences. To evaluate clones automatically, this list can be compared against user acceptance criteria that specify the allowable number of discrepancies of each type. This strategy allows users to re-evaluate the same set of clones against different acceptance criteria as needed for use in other experiments. ACE manages the entire sequence validation process including contig management, identifying and annotating discrepancies, determining if discrepancies correspond to polymorphisms and clone finishing. Designed to manage thousands of clones simultaneously, ACE maintains a relational database to store information about clones at various completion stages, project processing parameters and acceptance criteria. In a direct comparison, the automated analysis by ACE took less time and was more accurate than a manual analysis of a 93 gene clone set.</p> <p>Conclusion</p> <p>ACE was designed to facilitate high throughput clone sequence verification projects. The software has been used successfully to evaluate more than 55,000 clones at the Harvard Institute of Proteomics. The software dramatically reduced the amount of time and labor required to evaluate clone sequences and decreased the number of missed sequence discrepancies, which commonly occur during manual evaluation. In addition, ACE helped to reduce the number of sequencing reads needed to achieve adequate coverage for making decisions on clones.</p
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