Defect cluster recognition system for fabricated semiconductor wafers

The International Technology Roadmap for Semiconductors (ITRS) identifies production test data as an essential element in improving design and technology in the manufacturing process feedback loop. One of the observations made from the high-volume production test data is that dies that fail due to a systematic failure have a tendency to form certain unique patterns that manifest as defect clusters at the wafer level. Identifying and categorising such clusters is a crucial step towards manufacturing yield improvement and implementation of real-time statistical process control. Addressing the semiconductor industry's needs, this research proposes an automatic defect cluster recognition system for semiconductor wafers that achieves up to 95% accuracy (depending on the product type)

Facies Analysis, Sedimentology and Paleocurrent of the Quaternary Nenering Formation, Pengkalan Hulu, Malaysia

Nenering Formation is essentially made up of semi-consolidated sediments, which are divided into basal conglomerate beds, conglomeratic sandstone, cross-bedded sandstone, and siltstone to muddy layers facies. It is overlie unconformable to the Berapit Formation, but conformable to the Kroh and Grik Formations. The stratigraphy of Nenering Formation is a fining upwards sequence where the thickness of conglomerate beds become thinner upwards and become thicker for conglomeratic sandstone. The thickness varies from 0.5 m to tenths of meters. The more sandy in the upper portion (cross-bedded sandstone) overlie with thin siltstone and mudstone facies. The clast and grain composition suggested that the material making up the sedimentary sequence were derived predominantly from the erosion of granitoid rocks and sedimentary and metamorphic rocks constitute a minor provenance. Imbrications and the trend sizes of clasts indicate that the palaeo-current flow toward northeast. Cross bedding that was found in conglomerate and sandstone indicates the main channel depositional environment. The sequence stratigraphy of this area match with the Saskatchewan fluvial braided channel model. Formasi Nenering tersusun atas sedimen semi-terkonsolidasi yang terdiri atas lapisan basal konglomerat, batupasir konglomeratik, batupasir berlapisan silang siur, batulanau hingga fasies berlapisan lempung. Formasi Nenering terletak tidak selaras di atas Formasi Berapit, tetapi terletak selaras di atas Formasi Kroh dan Formasi Grik. Stratigrafi Formasi Nenering adalah menghalus ke atas, dimana ketebalan batuan konglomerat semakin menipis ke arah atas, sedangkan batupasir konglomeratik menjadi menebal ke arah atas. Ketebalan perlapisan berkisar pada 0,5 meter hingga puluhan meter. Komposisi pasir yang lebih dominan pada bagian atas (batupasir silang siur) terletak di atas fasies lapisan tipis batulanau dan batulempung. Komposisi butiran dan klastika menunjukkan bahwa material yang menyusun sekuen sedimen didominasi berasal dari erosi batuan granitik, batuan sedimen dan sedikit dari batuan metamorf. Indikasi imbrikasi dan kecenderungan Perubahan ukuran material klastika menunjukkan bahwa aliran arus purba mengarah ke timur laut, sedangkan perlapisan silang siur pada batuan konglomerat dan batupasir mengindikasikan lingkungan pengendapan berupa sungai. Sekuen stratigrafi di daerah ini sesuai dengan model lingkungan pengendapan sungai teranyam fluvial Saskatchewan

The preparation of common prebiotic oligosaccharides with defined degree of polymerization

Prebiotics are a subset of dietary fiber that is growing in demand within the food industry. The health benefits of prebiotics have been well established, leading to the increase in its incorporation into various food products. Given the importance of prebiotics as functional ingredients, it is important to understand their sensory properties. However, such knowledge is not well established because commercially available prebiotics are a mixture of saccharides with varying degree of polymerization (DP), including mono- and disaccharides. The goals of this research were to develop fractionation methods to prepare common prebiotic oligosaccharides [i.e., fructooligosaccharides (FOS), galacto-oligosaccharides (GOS), and xylooligosaccharides (XOS)] with well-defined DP from commercially available prebiotic oligosaccharides mixtures and to conduct chemical analysis to characterize the fractionated prebiotic oligosaccharides. To achieve the first goal, column chromatography was performed following principles of adsorption chromatography, whereby the analyte adsorbed to the surface of the stationary phase, then desorb and elute from the column by using a gradient mobile phase. During the chromatography run, cellulose was used as the stationary phase, whereas ethanol/water mixtures were used as the mobile phase. The packing material and solvents were selected based on their Generally Recognized as Safe (GRAS) status. The mobile phase was delivered to the column as a step gradient within the range of 85%-55% ethanol. The percentage used was determined by the solubility of the oligosaccharide, which were impacted by their chemical structures with heterogenous saccharides being more soluble (i.e., FOS, GOS) than homogenous saccharides (i.e., XOS). The specifics for chromatography conditions (i.e., sample load, volume of solvent, and mobile phase composition) differ based on the class of oligosaccharide and were tailored to best fit the separation capabilities of each oligosaccharide. It was important to find a balance between resolution, which impacted yield, and time taken for the chromatography run. Although the amount produced had relatively low (30-75%) recovery, the study made use of the fact that economical preparation does not require baseline resolution since the commercially available starting materials were relatively inexpensive. To confirm the identify and purity of the fractionated oligosaccharide preparations (FOS DP3, FOS DP4, GOS DP3, GOS DP4, XOS DP2, XOS DP3, and XOS DP4), various chemical analyses were performed. These included total carbohydrate analysis, moles quantification, nuclear magnetic resonance (NMR), and high-performance liquid chromatography (HPLC). Total carbohydrate analysis found that each prebiotic fraction was approximately 99-100% carbohydrate on a dry weight basis. Results from the moles quantification experiment and NMR analysis confirmed that the DP corresponds with the targeted profile for each oligosaccharide. HPLC results further verified the identity and purity for each oligosaccharide preparation through comparison with commercially available standards. Overall, this research produced and characterized seven fractions of prebiotic oligosaccharides with distinct chemical structure. This economical method of obtaining purified, fractionated prebiotic oligosaccharide is valuable to researchers interested in studying the properties of prebiotic oligosaccharides with specific chain lengths

Development of Taenia saginata asiatica metacestodes in SCID mice and its infectivity in human and alternative definitive hosts

Development of Taenia saginata asiatica metacestodes in SCID mice, and its infectivity in humans, golden hamsters, and Mongolian gerbils as alternative definitive hosts, were investigated. Cysticerci were recovered from SCID mice that were subcutaneously injected with hatched oncospheres of T. s. asiatica. The morphological changes of metacestodes were observed. The recovered cysticerci were fed to gerbils, hamsters and humans, to check for their infectivity. Tapeworms were recovered from gerbils and hamsters fed with 20 to 45 week-old cysticerci, and proglottids excretions were observed in human volunteers fed with 45 week-old cysticerci. However, no tapeworms were recovered from gerbils fed with 10 week-old cysticerci. Our results suggest that T. s. asiatica oncospheres needed more than 20 weeks to develop to maturity in SCID mice to be infective to both their natural and alternative definitive hosts

Modelling cohesive-frictional particulate solids for bulk handling applications

Many powders and particulate solids are cohesive in nature and the strength often exhibits dependence on the consolidation stress. As a result, the stress history in the material leading up to a handling scenario needs to be considered when evaluating its handleability. This paper outlines the development of a DEM contact model accounting for plasticity and adhesion force, which is shown to be suitable for modelling the stress history dependent cohesive strength. The model was used to simulate the confined consolidation and the subsequent unconfined loading of iron ore fines with particle sizes up to 1.18mm. The predicted flow function was found to be comparable to the experimental results

Controlling laser spectra in a phaseonium photonic crystal using maser

We study the control of quantum resonances in photonic crystals with electromagnetically induced transparency driven by microwave field. In addition to the control laser, the intensity and phase of the maser can alter the transmission and reflection spectra in interesting ways, producing hyperfine resonances through the combined effects of multiple scattering in the superstructure.Comment: 7 pages, 4 figure

High Aspect Pattern Formation by Integration of Micro Inkjetting and Electroless Plating

This paper reports on formation of high aspect micro patterns on low temperature co-fired ceramic (LTCC) substrates by integrating micro inkjetting with electroless plating. Micro inkjetting was realized by using an inkjetting printer that ejects ink droplets from a printhead. This printhead consists of a glass nozzle with a diameter of 50 micrometers and a piezoelectric transducer that is coated on the nozzle. The silver colloidal solution was inkjetted on a sintered CT800 ceramic substrate, followed by curing at 200 degrees C for 60 minutes. As a result, the silver trace with a thickness of 200 nm was obtained. The substrate, with the ejected silver thin film as the seed layer, was then immersed into a preinitiator solution to coat a layer of palladium for enhancing the deposition of nickel. Electroless nickel plating was successfully conducted at a rate of 0.39 micrometers /min, and the thickness of traces was plated up to 84 micrometers. This study demonstrates that the integration of inkjetting with plating is an effective method to form high aspect patterns at the demand location.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838