bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lustrous Black Fine Ware at Gordion, Turkey: A Distinctive Sintered Slip Technology
Authors: Henrickson Robert C , Vandiver Pamela B. , Blackman M. James 
Published: April 2011

ABSTRACTPotters at ancient Gordion (Turkey) produced a distinctive fine ware with a black glossy finish during at least the period 700-500 BC. Visual examination suggested a sintered slip finish. Study using SEM, EDS, INAA, x-ray diffraction, and refiring has confirmed this hypothesis. The technology was characterized by a relatively low firing temperature, large amounts of flux, a darkening wash added over the slip, and use of both calcareous and non-calcareous clays.
Engineered Low Resistivity Titanium-Tantalum Nitride Films by Atomic Layer Deposition
Authors: Londergan Ana R. , Winkler Jereld L. , Vu Kim , Matthysse Lawrence , Seidel Thomas E. , Sneh Ofer 
Published: April 2011

ABSTRACTAtomic Layer Deposition (ALD) is an emerging ultra-thin film deposition technique for advanced microelectronics applications. Enabling features of ALD are precise control over film thickness, excellent conformality and relative insensitivity to wafer size. Additionally, ALD allows interface and film engineering that can be utilized to maximize device performance within the minimum feature size requirements. This paper reports on the compositional, structural and electrical properties of engineered Ti-Ta-N composite films grown by ALD at 360°C. For a wide range of composition these Ti-Ta-N films exhibit resistivity from 500 to 2000 μω-cm, high density, and 100 % step coverage. Additionally, the ability to control texture by changing film composition is established. Based on experimental results, an approach to grow Composite Engineered Barriers by ALD (CEBA) is described that could provide a solution to the challenging barrier requirements.
Electromigration Characterization of Damascene Copper Interconnects: Comparison Between CVD Copper and ECD Copper.
Authors: Berger Thierry , Arnaud Lucile , Tartavel Gérard , Lormand Gérard 
Published: April 2011

ABSTRACTWe have characterized the electromigration performance of copper damascene interconnects using moderately and highly accelerated lifetime tests respectively at package and wafer level. Two metallizations have been studied: Chemical Vapor Deposition (CVD) copper deposited on CVD TiN (Process A) and electroplated (ECD) copper deposited on CVD TiN using 90 nm of CVD copper as a seed-layer (Process B). All metallizations were passivated with SiO2. Two line widths have been characterized: 0.6μm and 4μm.For wide lines, we obtained similar activation energies (Ea) for both metallizations (0.63 for process A and 0.65 eV for process B). For narrow lines, the Ea value is 0.8eV for CVD copper whereas it is higher than 1eV for ECD copper. For wide lines of both metallizations, failure analysis performed with a Scanning Electron Microscope (SEM) gave clear evidences that microstructural gradients have a strong impact on voids and extrusions formation (i.e. that grain boundaries are an active diffusion path in spite of low Ea values). For narrow lines, diffusion at the upper interface is believed to be the main diffusion path.From the reliability point of view, the extrapolated lifetimes of the metallization including ECD copper are much higher (1 to 2 orders of magnitude depending on the line width) than for CVD copper.
Electrical Characterization of Copper Penetration Effects in the Gate Oxide of MOS Devices
Authors: Mondon François , Cluzel Jacques , Blachier Denis , Morand Yves , Martel Laurent , Reimbold Gilles 
Published: April 2011

ABSTRACTCopper penetration in thermal oxide was investigated using MOS capacitors by annealing at 450 °C and bias-temperature stress at 250 °C. Copper induces minority carrier generation lifetime decay and oxide leakage current increase. Degradation is enhanced by capacitor biasing, which confirms the role of Cu+ ions. The current-voltage characteristics are consistent with Poole-Frenkel model, showing that electron transport proceeds through traps created in the oxide bulk by copper. When a negative bias is applied, copper traps are removed from oxide near SiO2-Si interface and the leakage current is cancelled but the generation lifetime remains nil, copper contamination of silicon surface being not removed.None of these effects are observed when the copper gate is separated from oxide by a 10 nm TiN layer, proving that this material is an efficient barrier against copper diffusion at 450°C.
Evolution of Property and Microstructure of P(VDF-TrFE) Copolymers Modified by Irradiation Introduced Defects
Authors: Cheng Z.-Y. , Li Zhimin , Ma Yanyun , Zhang Q. M. , Bateman Fred B. 
Published: April 2011

ABSTRACTThe effect of defects introduced by high-energy electron irradiation on microstructure and properties in poly(vinylidene fluoride- trifluoroethylene) [P(VDF-TrFE)] is reported. In studies of the copolymers, it is found that as defect concentration increases, the material can be changed from a normal ferroelectrics to a relaxor ferroelectrics (RFE) and then to a simple relaxor. Correspondingly, the crystalline morphology changes from a coexistence of polar and non-polar phases to a macroscopically uniform non- polar phase, as revealed by x -ray data. It was observed that the dielectric property in the copolymers with a different amount of defects was well described by the Vogel-Fulcher (V-F) relationship. Based on the experimental data, a critical size, which is the smallest size of crystal with ferroelectric phase, of about 5 nm was obtained for the copolymer. The RFE developed here exhibits a massive electrostrictive strain which is very attractive for many actuator and transducer applications and a high dielectric constant which is attractive for development of high- density energy storage capacitors and electronic packaging.
Direct observation and characterisation of the oxide nanostructured interface resulting from organosilane pre-treatment of aluminium
Authors: Whiting Mark J. , Stolojan Vlad , Rattana Ann , Watts John F. 
Published: April 2011

ABSTRACTThe pre-treatment of aluminium surfaces prior to adhesive bonding and coating processes is of major technological significance. However, the two major commercial pre-treatments, chromic acid and phosphoric acid anodising, both make use of Cr(VI) containing solutions with the attendant problems of waste disposal. The disposal of this harmful solution poses severe environmental problems. Therefore, other environmentally friendly alternatives are being investigated, one of the most popular candidates is the use of one-step pretreatment processes based on organosilane adhesion promoters.This study examines a model system made from polished aluminium sheet treated with an organosilane; γ-glcidoxypropyltrimethoxysilane (GPS). The interface was characterised by TEM carried out on microtomed sections. The information gained from imaging and Electron Energy Loss Spectroscopy (EELS) analysis revealed a layer of oxide, approximately 70 nm thick. Silicon was found to have been incorporated within this oxide layer. Thus it is suggested that during the curing of the GPS, at elevated temperature, growth of aluminium oxide takes place which gives rise to an Al/O/Si phase.
Conformations in PET-steel laminates studied by FTIR
Authors: Rastogi R. , Vellinga W.P , Asselen O.LJ.v , Meijer H.E.H. 
Published: April 2011

ABSTRACTPET-steel interfaces were studied with FTIR. Differences in conformations of PET in free standing films and supported films in laminates are attributed to the presence of the PET-metal interface. These differences could be accentuated by varying the physical environment ie. by annealing or mechanically loading both free and supported films.
Mechanical Enhancement Of Nanoporous Low-K Films As Interlayer Dielectrics By Ion Implantation
Authors: Roy Alok Nandini U. , Patel Zubin P. , Mallikarjunan A. , Bakhru H. , Lu T.-M. 
Published: April 2011

ABSTRACTThin films of Ultra-Low K materials such as Xerogel (K=1.76) and MSQ (K=2.2) were implanted with argon, neon, nitrogen, carbon and helium with 2 × 1015 cm−2 and 1 × 1016 cm−2 dose at energies varying from 20 to 50 keV at room temperature. In this work we showed that the surface hardness of the porous films is improved five times as compared to the as-deposited porous films sacrificing the dielectric constant up to 15% after implantation (e.g., from 1.76 to 2.0). The hardness persists after 450 °C annealing. It is also shown that implantation can prevent the penetration of chemical gases such as CVD precursors in the Ultra-Low K dielectrics during a CVD process.
The Role of Keto Defect Sites for the Emission Properties of Polyfluorene-Type Materials
Authors: List Emil J.W. , Guentner Roland , Freitas Patricia Scanducci de , Scherf Ullrich 
Published: April 2011

ABSTRACTIn this paper we have identified a dominant degradation mechanism of blue light emitting polyfluorene (PF) type polymers, which turns the desired blue emission colour of these polymers into an undesired blue-green emission. As shown low energy emission band at 2.2–2.3 eV can be identified as the emission from exciton and/or charge trapping keto defect sites (9-fluorenone sites), which in fact can be regarded as emission of a guest (defect) accidentally incorporated into the π-conjugated PF backbone. We present spectroscopic evidence for the formation of keto defect sites in 9-monoalkylated polyfluorenes (PF-a) which are identified as the source of the strong low energy emission band. Furthermore we show that the keto defects can be generated directly during polymer synthesis as show for the PF-a or can be formed as main channel of an (photo- or electro-) oxidative degradation process as show for the 9-bisalkylated PF.
Blood Compatibility of Stainless-Steel and Titanium Immobilized with Alginic Acid Layers
Authors: Yoshioka Tomohiko , Tsuru Kanji , Hayakawa Satoshi , Osaka Akiyoshi 
Published: April 2011

ABSTRACTγ-Aminopropyltriethoxysilane (γ-APS) was grafted on stainless-steel and titanium substrates, and subsequently alginic acid layer was immobilized on them. Their surfaces were characterized with X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Blood compatibility of thus obtained substrates was evaluated in terms of both the number of the adhered platelets and blood clotting factors for plasma contacted with the substrates such as active partial thromboplastin time (PTT), prothrombin time (PT), and amount of fibrinogen (Fib). The steel and titanium substrates with alginic acid layer did not affect blood clotting factors. In vitro platelet adhesion assay indicated that those substrates adhered less number of platelets than non-treated substrates. Hence the alginic acid immobilization leads to blood compatible surfaces.
The Nanomechanical Effect of Dendrimer Interlayers Underneath Cu Ultrathin Films
Authors: Zhang Junyan , Curry Micheal , Street Shane 
Published: April 2011

ABSTRACTTwo kinds of dendrimers, DAB and PAMAM (with the same terminal groups but different branched repeat units), were chosen as interlayers for Cu ultrathin films deposited on native oxide Si(100) wafers. 10 nm Cu thin films were deposited directly on the dendrimer monolayers by DC sputtering at room temperature. The nanomechanical results show that PAMAM and DAB have significant effects on the properties of the resulting films, with the DAB layer acting as a stiffer ‘spring’, compared to PAMAM, underneath the Cu films. Both dendrimer interlayers lower the hardness of the film, compared to Cu alone; the effect is greater for PAMAM than DAB interlayers. However, the introduction of either dendrimer monolayer significantly increased the elasticity of the Cu film.
SFM and TOF-SIMS Study of Novel Self-Organization phenomena in mixed LB monolayers
Authors: Pignataro B. , Sardone L. , Licciardello A. , Marletta G. 
Published: April 2011

ABSTRACTMixed monolayers of dimyristoylphosphatidylcholine (DMPC) and quercetin palmitate (QP) in a molar ratio of 25/75 have been transferred on mica and oxygen plasma cleaned silicon by the Langmuir-Blodgett (LB) technique at different subphase temperatures. Scanning Force Microscopy (SFM) in height, phase and lateral force modes has been employed to investigate the structural and mechanical features at nanoscopic level of these samples. Although the two molecules show a wide range of miscibility at 37 °C, they give rise to phase separation at 10 °C. This last system provides a new example of nanometric scale self-organization. In particular spiral shaped domains rising from the wrapping-up of nanoscopic fiber-like structures have been observed. The high resolution achieved by the use of the dynamic scanning force microscopy operating in the net attractive regime allow to visualize characteristic nanoscopic rupture points along the supramolecular fibers. High mass resolution Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) spectra showed DMPC- as well as QP-related peaks. The ToF-SIMS spectra from the nanostructured samples (10 °C) have been compared with those from the homogeneous ones (37 °C). The phase separated samples provides interesting secondary ions that highlight the QP supramolecular condensation within the fiber-like structures.
Chemical Force Microscopic Study of UV Excimer Laser Irradiated Polyamide
Authors: Yip Joanne , Chan Kwong , Sin Kwan Moon , Lau Kai Shui 
Published: April 2011

ABSTRACTRecently, there has been great interest in physico-chemical treatment for modifying polymer surfaces. UV Excimer laser irradiation is of particular interest in morphological and chemical modifications. Depending on the laser energies used, effects of laser treatment fall into two groups: above the ablation threshold the ripple structures of micrometer size form (high-fluence), and below the ablation threshold the sub-micron structures emerge (low-fluence).Traditional methods of studying chemical properties are Fourier-transform infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectroscopy. The ability of a relatively new technique involving chemical force microscopy (CFM) can be used to image and discriminate the areas exposing different functional groups on polymers. Gold-coated AFM tip modified with carboxylic acid (-COOH) terminated self-assembled alkanethiol monolayers (SAMs) was used to measure the adhesive forces between the tip and the laser treated samples in a water or hexane medium.The CFM results showed that high-fluence laser treated polyamide has the highest adhesive force with the modified tip in a water medium when compared with the control and low-fluence ones. The adhesive force is due to electrostatic attraction between the negatively charged tips terminating in COO- groups and the positively charged sample terminating in NH+ groups. This indicates that the high-fluence laser treated sample results in the formation of many amine end-groups on the polymer surface. In comparison, only low-fluence treated surface shows adhesive force with the modified tip in a hexane medium. This implies that the low-fluence laser treated polyamide has substantially more hydrophilic groups than the untreated and high-fluence laser treated samples. The adhesion force measurements by CFM allow one to have better understanding of surface chemical modifications induced by UV excimer laser.
Atomic and Electronic Structures of Au/TiO2 Catalyst – First-Principle Calculations –
Authors: Okazaki Kazuyuki , Morikawa Yoshitada , Tanaka Shingo , Ichikawa Satoshi , Tanaka Koji , Kohyama Masanori 
Published: April 2011

ABSTRACTThe atomic and electronic structures of Au/TiO2(110) systems have been theoretically investigated based on the density functional theory. We have examined Au adsorption on the stoichiometric TiO2(110) surface and on the Ti-rich surface formed by the removal of bridging-oxygen atoms (VOB surface) and the O-rich surface formed by the removal of 6-fold titanium and bridging-oxygen atoms (VTi6OB surface). For the stoichiometric surface, the stable site for the Au adatom is the hollow site of one bridging-oxygen and two in-plane oxygen atoms or the on-top site above 5-fold titanium atom. For the Ti-rich VOB surface, the bridging site of 6-fold titanium atoms along [001] direction is the most stable. In addition, the vacant site of 6-fold titanium atom is the most stable for the O-rich VTi6OB surface. The adhesive energies between the Au adlayer and the TiO2 surface are larger for the non-stoichiometric surfaces than that for the stoichiometric surface. The charge transfer between the Au adatom and the substrate is small for stoichiometric surface. For the Ti-rich VOB surface, the electron transfer occurs from the 6-fold Ti to the Au, while from the Au to the in-plane oxygen for the O-rich VTi6OB surface. It can be said that the TiO2 surface conditions such as defects or non-stoichiometry strongly affect the adsorption energy and electron structure of the Au adsorbed system. This point should be closely related the catalytic property of the Au/TiO2 system.
Microstructure of precipitated Au Nanoclusters in Single Crystal MgO
Authors: Wang C. M. , Thevuthasan S. , Shutthanandan V. , Cavanagh A. , Walton J. , Jiang W. , Weber W. J. , Thomas L. E. , Wang L. M. , Lian Jie 
Published: April 2011

ABSTRACTGold nanoclusters dispersed in single crystal MgO were prepared by ion implantation and subsequent annealing at 1000 °C. The morphological feature, size, crystallographic orientation of the Au nanoclusters with respect to the MgO matrix, and the interface structure between the Au nanoclusters and MgO were investigated using transmission electron microscopy. During annealing, the Au clusters nucleate coherently in the MgO lattice, leading to an epitaxial orientation relationship of [010] MgO// [010]Au and (200)MgO//(200)Au that is maintained for all the Au clusters. A critical size for the coherent-semicoherent interface transition is observed to be in the range from ∼5 to 8 nm for Au clusters in MgO. Au clusters larger than this critical size exhibit faceting on the {001} planes. The precipitated Au also exhibits internal dislocations.
Characterization of High-k Dielectric Films with Tunneling AFM
Authors: Wang Xiang-Dong , Kulik Joe , Edwards N. V. , Samavedam S. B. , Lu Shifeng 
Published: April 2011

ABSTRACTIn this paper, we report the leakage current characterization of HfO2 high-k dielectric thin films by using tunneling AFM, which utilizes a conducting AFM probe to detect current passing through the sample and the probe while simultaneously acquiring a topographic image. We have studied tunneling current behavior of HfO2 films by characterizing the hot spots, which are characterized by excessive local leakage current, as well as the overall current distribution. Tunneling AFM results show sensitive dependence of tunneling current with variation of film thickness. The current distribution can be described approximately by a log-normal distribution, which is consistent with the characteristics of the thickness variation. Furthermore, the film structure and thickness were also characterized with TEM and spectroscopic ellipsometry.
Site-specific cross-sectioning of carbon nanotube-to-metal junctions for high spatial resolution chemical and structural analysis
Authors: Dovidenko K. , Abramson N. L. , Rullan J. 
Published: April 2011

ABSTRACTIn this study, we have demonstrated successful site-specific cross-sectioning of carbon-nanotube - metal junctions which provided samples suitable for high resolution transmission electron microscopy and electron energy loss spectroscopy. For the cross-sectioning, we have suggested a modified technique based on combination of the Focused Ion Beam (FIB) lift-out and the conventional Ar+ ion milling techniques. Electron-transparent cross-sections of multiwall carbon nanotubes showing no significant surface amorphization or Ga contamination (typical artifacts of conventional FIB lift-out technique) were obtained. High-resolution transmission electron microscopy and electron energy loss spectroscopy of a multi-wall carbon nanotube cross-section have been carried out.
Analysis of Stacking Structure of Cup-Stacked Type Carbon Nanofibers
Authors: Oshida Kyoich , Nakazawa Tatsuo , Osawa Kozo , Hayashi Takuya , Endo Morinobu , Yanagisawa Takashi , Dresselhaus Mildred S. 
Published: April 2011

ABSTRACTThe lattice images of the new type (cup-stacked type) carbon nanofibers were observed by high resolution transmission electron microscopy (HRTEM) and the detailed structure was analyzed by image processing. The angle of opposed graphitic basal planes was measured from power spectrum obtained by 2 dimensional first Fourier transform. The structures of the slanted (00·1) lattice planes, which appear at the cross section of the fiber wall, were shown by means of this image analysis technique. Defects were observed in the ordered structure of this material. The (00·1) lattice planes show large fluctuation in alignment of them and the (10·0) lattice planes make several angles with the (00·1) lattice planes. The average repeat distance d002 was estimated on the basis of d100 by HRTEM image and image analysis.
The Use of Surface Enhanced Raman Scattering for the Detection of Dipicolinic Acid on Silver Nanoparticles
Authors: Phillips Terry E. , Sample Jennifer L. , Scholl Peter F. , Miragliotta Joseph 
Published: April 2011

ABSTRACTWe report on the use of surface enhanced Raman scattering (SERS) for the detection of dipicolinic acid (DPA) adsorbed on a silver (Ag) nanoparticle substrate. We have examined the interaction of DPA with Ag nanoparticles in a slightly basic, aqueous solution and determined that the molecule adsorbs as a dipicolinate anion on the metal surface. For micro molar or lower DPA concentrations in the colloid solution, no SERS activity from the adsorbed molecule was observed until nanoparticle aggregation was induced by reducing the pH with the addition of nitric acid. Following aggregation, the SERS response exhibited vibrational bands associated with both the pyridine ring and the carboxylate moieties in the adsorbed dipicolinate species. With proper control of the colloidal solution chemistry, the dipicolinate vibrational features could be observed in the SERS spectra at concentrations as low as 20 nano molar, a limit determined by the presence of solution-based contaminants on the Ag surface. In addition to the controlled DPA analyte studies, SERS was also able to detect the release of this molecule fromBacillus globigiispores, a non-toxic simulant forBacillus anthracis, which demonstrated the potential of this optical spectroscopy for the detection of biological and chemical agents.
Hardness and Abrasion Resistance of Nanocrystalline Nickel Alloys Near the Hall-Petch Breakdown Regime
Authors: Schuh Christopher A. , Nieh T. G. 
Published: April 2011

ABSTRACTThe breakdown of classical Hall-Petch scaling remains an area of scientific interest, and will govern the limiting strength of nanocrystalline alloys for structural applications. In this work we discuss the hardness and scratch resistance of nanocrystalline nickel and nickel-tungsten solid solution alloys, assessed through nanoindentation and nano-scratch techniques. The materials have been prepared by electrodeposition, and are fully dense with grain sizes between 6 and 22 nm. In this range of grain sizes, there is some evidence for a breakdown of Hall-Petch scaling, reflected in both the hardness and abrasion data. The role of solid solution alloying on this breakdown is also discussed.