6,559 research outputs found

    Product assurance technology for custom LSI/VLSI electronics

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    The technology for obtaining custom integrated circuits from CMOS-bulk silicon foundries using a universal set of layout rules is presented. The technical efforts were guided by the requirement to develop a 3 micron CMOS test chip for the Combined Release and Radiation Effects Satellite (CRRES). This chip contains both analog and digital circuits. The development employed all the elements required to obtain custom circuits from silicon foundries, including circuit design, foundry interfacing, circuit test, and circuit qualification

    Lumped element kinetic inductance detectors maturity for space-borne instruments in the range between 80 and 180 GHz

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    This work intends to give the state-of-the-art of our knowledge of the performance of LEKIDs at millimetre wavelengths (from 80 to 180~GHz). We evaluate their optical sensitivity under typical background conditions and their interaction with ionising particles. Two LEKID arrays, originally designed for ground-based applications and composed of a few hundred pixels each, operate at a central frequency of 100, and 150~GHz (Δν/ν\Delta \nu / \nu about 0.3). Their sensitivities have been characterised in the laboratory using a dedicated closed-circle 100~mK dilution cryostat and a sky simulator, allowing for the reproduction of realistic, space-like observation conditions. The impact of cosmic rays has been evaluated by exposing the LEKID arrays to alpha particles (241^{241}Am) and X sources (109^{109}Cd) with a readout sampling frequency similar to the ones used for Planck HFI (about 200~Hz), and also with a high resolution sampling level (up to 2~MHz) in order to better characterise and interpret the observed glitches. In parallel, we have developed an analytical model to rescale the results to what would be observed by such a LEKID array at the second Lagrangian point.Comment: 7 pages, 2 tables, 13 figure

    Initial test results on bolometers for the Planck high frequency instrument

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    We summarize the fabrication, flight qualification, and dark performance of bolometers completed at the Jet Propulsion Laboratory for the High Frequency Instrument (HFI) of the joint ESA/NASA Herschel/Planck mission to be launched in 2009. The HFI is a multicolor focal plane which consists of 52 bolometers operated at 100 mK. Each bolometer is mounted to a feedhorn-filter assembly which defines one of six frequency bands centered between 100-857 GHz. Four detectors in each of five bands from 143-857 GHz are coupled to both linear polarizations and thus measure the total intensity. In addition, eight detectors in each of four bands (100, 143, 217, and 353 GHz) couple only to a single linear polarization and thus provide measurements of the Stokes parameters, Q and U, as well as the total intensity. The measured noise equivalent power (NEP) of all detectors is at or below the background limit for the telescope and time constants are a few ms, short enough to resolve point sources as the 5 to 9 arc min beams move across the sky at 1 rpm

    Statistical Methods for Large Flight Lots and Ultra-high Reliability Applications

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    We present statistical techniques for evaluating random and systematic errors for use in flight performance predictions for large flight lots and ultra-high reliability applications

    OXIDATION OF SILICON - THE VLSI GATE DIELECTRIC

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    Silicon dominates the semiconductor industry for good reasons. One factor is the stable, easily formed, insulating oxide, which aids high performance and allows practical processing. How well can these virtues survive as new demands are made on integrity, on smallness of feature sizes and other dimensions, and on constraints on processing and manufacturing methods? These demands make it critical to identify, quantify and predict the key controlling growth and defect processes on an atomic scale.The combination of theory and novel experiments (isotope methods, electronic noise, spin resonance, pulsed laser atom probes and other desorption methods, and especially scanning tunnelling or atomic force microscopies) provide tools whose impact on models is just being appreciated. We discuss the current unified model for silicon oxidation, which goes beyond the traditional descriptions of kinetic and ellipsometric data by explicitly addressing the issues raised in isotope experiments. The framework is still the Deal-Grove model, which provides a phenomenology to describe the major regimes of behaviour, and gives a base from which the substantial deviations can be characterized. In this model, growth is limited by diffusion and interfacial reactions operating in series. The deviations from Deal-Grove are most significant for just those first tens of atomic layers of oxide which are critical for the ultra-thin oxide layers now demanded. Several features emerge as important. First is the role of stress and stress relaxation. Second is the nature of the oxide closest to the Si, both its defects and its differences from the amorphous stoichiometric oxide further out, whether in composition, in network topology, or otherwise. Thirdly, we must consider the charge states of both fixed and mobile species. In thin films with very different dielectric constants, image terms can be important; these terms affect interpretation of spectroscopies, the injection of oxidant species and relative defect stabilities. This has added importance now that P-b concentrations have been correlated with interfacial stress. This raises further issues about the perfection of the oxide random network and the incorporation of interstitial species like molecular oxygen.Finally, the roles of contamination, particles, metals, hydrocarbons etc are important, as is interface roughness. These features depend on pre-gate oxide cleaning and define the Si surface that is to be oxidized which may have an influence on the features listed above

    Evaluation of Enhanced Low Dose Rate Sensitivity in Discrete Bipolar Junction Transistors

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    We evaluate the low dose rate sensitivity in several families of discrete bipolar transistors across device parameter, quality assurance level, and irradiation bias configuration. The 2N2222 showed the most significant low dose rate sensitivity, with low dose rate enhancement factor of 3.91 after 100 krad(Si). The 2N2907 also showed critical degradation levels. The devices irradiated at 10 mrad(Si)/s exceeded specifications after 40 and 50 krad(Si) for the 2N2222 and 2N2907 devices, respectively

    Bubble memory module

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    Design, fabrication and test of partially populated prototype recorder using 100 kilobit serial chips is described. Electrical interface, operating modes, and mechanical design of several module configurations are discussed. Fabrication and test of the module demonstrated the practicality of multiplexing resulting in lower power, weight, and volume. This effort resulted in the completion of a module consisting of a fully engineered printed circuit storage board populated with 5 of 8 possible cells and a wire wrapped electronics board. Interface of the module is 16 bits parallel at a maximum of 1.33 megabits per second data rate on either of two interface buses

    Two- and Three-dimensional High Performance, Patterned Overlay Multi-chip Module Technology

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    A two- and three-dimensional multi-chip module technology was developed in response to the continuum in demand for increased performance in electronic systems, as well as the desire to reduce the size, weight, and power of space systems. Though developed to satisfy the needs of military programs, such as the Strategic Defense Initiative Organization, the technology, referred to as High Density Interconnect, can also be advantageously exploited for a wide variety of commercial applications, ranging from computer workstations to instrumentation and microwave telecommunications. The robustness of the technology, as well as its high performance, make this generality in application possible. More encouraging is the possibility of this technology for achieving low cost through high volume usage
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