Spin-on-glass (SOG) process-induced tungsten residue in a semiconductor manufacturing procedure

In this article, a case of Spin-on-Glass (SOG) process-induced tungsten residue was reported. The case was found after the tungsten etchback process of filling vias. A possible failure mechanism was proposed. Based on the review of our process flow, it is believed that the tungsten residue might result from the hydrodynamic effects of SOG.     

HgCdTe on Si: Present status and novel buffer layer concepts

We discuss buffer-layer concepts for the synthesis of low defect-density HgCdTe epilayers on Si for both hybrid and monolithically integrated, infrared focal-plane arrays (IRFPAa). The primary technical problems to overcome include the 19% lattice-parameter mismatch between HgCdTe and Si, and the (211)B surface orientation required for molecular-beam epitaxy (MBE), the growth technique of choice for HgCdTe. We provide a general overview of IRFPAs, motivations for realizing HgCdTe on Si, the current state-of-the-art parameters as a baseline, and three novel buffer-layer concepts and technologies based on (1) obedient GeSi films on SiO₂, (2) wafer bonding, and (3) chalcogenides.     

Recursive order-statistic soft morphological filters

A new class of recursive order-statistic soft morphological (ROSSM) filters are proposed and their important properties related to morphological filtering are developed. Criteria for specific selection of parameters are provided to achieve excellent performance in noise reduction and edge preservation. It is shown through experimental results that the ROSSM filters, compared the order-statistic soft morphological filters or other well known nonlinear filters, have better outcomes in signal reconstruction. Two examples are given for demonstrating the flexibility of the proposed filters in signal processing applications     

The Yin and Yang of oxidation in the development of the fatty streak. A review based on the 1994 George Lyman Duff Memorial Lecture

Recent data support the hypothesis that the fatty streak develops in response to specific phospholipids contained in LDL that become trapped in the artery wall and become oxidized as a result of exposure to the oxidative waste of the artery wall cells. The antioxidants present within both LDL and the microenvironments in which LDL is trapped function to prevent the formation of these biologically active, oxidized lipids. Enzymes associated with LDL and HDL (eg, platelet activating factor acetylhydrolase) or with HDL alone (eg, paraoxonase) destroy these biologically active lipids. The regulation and expression of these enzymes are determined genetically and are also significantly modified by environmental influences, including the acute-phase response or an atherogenic diet. The balance of these multiple factors leads to an induction or suppression of the inflammatory response in the artery wall and determines the clinical course.     

Proton magnetic resonance spectroscopic imaging in childhood ataxia with diffuse central nervous system hypomyelination

The spatial distribution of metabolite signal intensities can be measured within entire sections of the brain by proton magnetic resonance spectroscopic imaging (1H-MRSI). A group of six patients (4 unrelated girls and 2 brothers from 5 families) with childhood ataxia with diffuse CNS hypomyelination (CACH) underwent long-echo-time, single-slice 1H-MRSI. Relative to controls, there was a decrease in the signal intensity of N-acetylaspartate, choline, and creatine throughout the white matter in all six patients. We identified lactate signals in white matter in three of them with advanced disease. The degree of white matter involvement was not homogeneous over the entire patient group, but did correlate with clinical presentation. Deep and posterior white matter tended to be more involved. There were no 1H-MRSI abnormalities in the gray matter. 1H-MRSI findings suggest that this syndrome is secondary to a metabolic defect causing hypomyelination, axonal degeneration, and, in the most compromised cases, accumulation of lactate. This study shows that CACH is not limited to girls.     

Rheological properties of multicomponent polymer systems undergoing melting or softening during compounding

The rheological characteristics of a number of polymer blends, including amorphous and semi-crystalline plastic matrices, during melting or softening, are analyzed with a batch mixer. The physical changes accompanying the phase transitions taking place as the slat-and-pepper blends are heated and mixed in the region of their component melt transition temperatures are monitored visually through a transparent window with video recordings. The torque of mixing and the mixture temperature are also recorded continuously. The strong effects of additives such as filler or lower melting resin as well as rotor speed, degree of fill, and ram pressure were observed.     

GaAs power MESFET with 41-percent power-added efficiency at 35 GHz

A GaAs power MESFET has been optimized for Ka-Band operation. The device has an n⁺ ledge channel structure with a 0.25-μm gate on MBE-grown material. An output power density of 0.71 W/mm was achieved with 5.2-dB gain and 34% power-added efficiency. When tuned for maximum efficiency, a power-added efficiency of 41% was obtained with a power density of 0.61 W/mm and a gain of 5.6 dB     

Aflatoxin can be degraded by the mycelium of aspergillus parasiticus.

Aflatoxins B1, B2, G1, and G2 were degraded by the 8- and 16-day old but not by the 4-day old mycelium of a toxigenic strain of Aspergillus parasiticus. The 16-day old mycelium degraded the toxin more rapidly than did the 8-day old mycelium. Degradation of toxin by the mycelium was similar at pH 2.5 and 6.0.     

Surface morphology and photoluminescence of InAs quantum dots grown on [11~0]-oriented streaked islands under ultra-low V/III ratio

The influences of the low V/III ratio on the surface morphologies and temperature-dependent photoluminescence spectrum of InAs-GaAs quantum dots (QDs) prepared by organometallic vapor phase epitaxy are investigated. Due to the accumulation of In adatoms at the multiatomic step edge on [001] 2/sup 0/ off toward an [111] n-type GaAs substrate, InAs island growth with /spl sim/1 ML coverage takes place prior to the InAs QD formation. With increasing InAs coverage, self-assembled InAs QDs are observed near the InAs islands, which is attributed to the recapture of desorbed In atoms nucleating with supplied As atoms on the edge along [11~0]-orientation of the GaAs substrate.