bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Formation of Tin-Encapsulated Silver Films by Nitridation of Silver-refractory metal alloys in NH3
Authors: Adams Daniel , Alford T. L. , Laursen T. , Deng F. , Morton R. , Lau S. S. 
Published: April 2011

AbstractEncapsulated Ag(Ti) films on oxidized silicon were obtained by nitridation of Ag(19 at.% Ti) alloys in NH3 at temperatures between 400-700°C for various times. Upon annealing Ti segregates to the surface and alloy/SiO2 interface to form a TiN(O) surface layer and a TiO/Ti5Si3 interfacial bilayer structure. Resistivity values of 2.5 μΩ-cm were measured in the encapsulated Ag alloys. The results suggest that resistivity is controlled by the residual Ti concentration.
Ti Salicide Technology using Nitrogen Diffusion from Tin Cap by RTA in an Argon Ambient
Authors: Ishigami T. , Matsubara Y. , Iguchi M. , Horiuchi T. 
Published: April 2011

AbstractA new Ti salicide technology that uses nitrogen diffusion from a TiN cap layer by RTA in an argon ambient is demonstrated. The key point for achieving a fine-line Ti salicide iscontrolling the two competing reaction processes in thin Ti (<30 nm): nitridation at the Ti surface, and silicidation at the interface between Ti and Si. In the conventional Ti silicidation process using atmospheric nitrogen RTA, however, control of nitridation is difficult due to a high concentration of nitrogen at the Ti surface. Therefore, the remaining TiSi2 film is very thin and contains larger amount of nitrogen [1]. The new technology provides good controllability of Ti nitridation for thin Ti by using an argon atmospheric RTA.A major advantage of nitrogen diffusion from a TiN cap layer is controllability of the nitrogen concentration at the interface between TiN and Ti. After TiN and Ti sputtering, silicidation was performed by two-step annealing in argon (RTA1: 680°C, 30 s; RTA2: 800°C, 10 s). When the thickness ratio (TiN/Ti) was 1, Ti2N formed on the field oxide. The Ti2N layer suppresses excessive silicidation over the field oxide in the same way that TiN does. Sheet resistance results show that silicidation is suppressed by the impurity effect in the case of thinner Ti (<20 nm). Furthermore, when TiN is thick (>20 nm), large metal strength retards silicidation [2]. Optimization of TiN/Ti thickness (20/20 nm) is essential for achieving low sheet resistance of 10 Ω for p+ and n+ quarter micron lines.
Rapid Thermal Chemical Vapor Formation of TiSi2: An alternative refractory metallization process for device fabrication
Authors: Gladden D. B. , Ren X. , Weintraub C. E. , Öztürk M. C. 
Published: April 2011

AbstractScaling of MOSFETs into the deep submicron regime requires novel metallization schemes to form low resistivity contacts on ultra-shallow junctions. In this paper, we present our recent results on rapid thermal chemical vapor formation (RTCVF) of TiSi2. In this process, the gaseous Ti source, TiCl4 (g), reacts with solid Si to form C54 TiSi2(s) at temperatures as low as 700°C with a resistivity of 15-20μΩ-cm without a follow-up anneal. In this paper, we explore the previously reported barrier for nucleation of TiSi2 on Si at temperatures below 800°C. Without proper surface preparation, this barrier results in an incubation time which can vary according to the conditions of the surface and the deposition environment. We show that contrary to general belief, surface morphology instead of surface cleanliness is the most likely contributor to this barrier. We also show that if in-situ deposition of a Si-Ge layer precedes TiSi2 formation, the incubation time can be completely eliminated. Experiments performed in a temperature range of 650°C - 800°C indicate an approximate activation energy of 100 kJ/mol. The process provides excellent selectivity to both SiO2 and Si3N4 and little growth rate dependence on patterns in the 2 μm - 200 μm regime.
Microscopic Driving Forces For Electromigration
Authors: Sorbello Richard S. 
Published: April 2011

AbstractElectromigration in metals is due to microscopic forces acting on mobile defects. These microscopic forces arise from the local electric field that accompanies electron transport, and the resulting defect migration is a consequence of the dynamic response of the defect to this local field. Theoretical results are given for the local electric field and the electromigration driving force on impurities in bulk systems and in metallic microstructures where surfaces, grain boundaries and dislocations play an important role. Extensions of the theory are described for mesoscopic systems, and local heating is shown to be an important effect as the size of the system becomes smaller and the electron current is larger.
Structural, Textural and Catalytic Properties of Al-, Ti - Pillared Clays
Authors: Ramos-Galván C. E. , Dominguez J. M. , Sandoval-Robles G. , Castillo-Mares A. , Nava E N. 
Published: April 2011

AbstractAl-, Ti- and Zr-pilared clays were characterized and NiMo/Pilc's were tested in HDS reactions. The combination of activity measurements with Mossbauer Spectroscopy and x-ray microanalysis at microscopical scale give insight in the metal phases migration during pillaring, reaction and regeneration steps. α-Fe phase in free Fe2O3 islands predominate together with structural Fe3+ phase, but during the catalytic reaction Fe2+ forms. Delamination of the Ti- and Zr-Clay supports, together with high Lewis acidity might enhance their catalytic properties.
Coadsorption of Nitriles and Co On Cu-Zsm-5: An In Situ FTIR Spectroscopic Study
Authors: Szanyi J. , Paffett M. T. 
Published: April 2011

AbstractThe coadsorption of acetonitrile (ACN) or deuterated acetonitrile (dACN) with CO at Cu-ZSM-5 reveals several interesting features concerning the partial valency of Cu. Specifically, CO binds at Cu+1 and Cu° centers (in the absence of preadsorbed ACN) and exhibits C-O stretching frequencies of 2157 cm−1 and 2112 cm−1, respectively. Carbon monoxide readily adsorbs at an ACN (or dACN) saturated Cu-ZSM-5 and exhibits a C-O stretch of 2122 cm−1, a value more consistent with a partially reduced Cu+1 center. Furthermore, the IR cross section for the CN stretch in a number of nitriles (ACN, dACN, and benzonitrile) coadsorbed with CO displays interesting effects attributed to rehybridization and changes in CN dipole moment.
Porous Silicon Structural Evolution from In-Situ Luminescence and Raman Measurements
Authors: Tallant D. R. , Kelly M. J. , Guilinger T. R. , Simpson R. L. 
Published: April 2011

AbstractWe performed in-situ photoluminescence and Raman measurements on an anodized silicon surface in the HF/ethanol solution used for anodization. The porous silicon thereby produced, while resident in HF/ethanol, does not immediately exhibit intense photoluminescence. Intense photoluminescence develops spontaneously in HF/ethanol after 18–24 hours or with replacement of the HF/ethanol with water. These results support a quantum confinement mechanism in which exciton migration to traps and nonradiative recombination dominates the de-excitation pathways until silicon nanocrystals are physically separated and energetically decoupled by hydrofluoric acid etching or surface oxidation. The porous silicon surface, as produced by anodization, shows large differences in photoluminescence intensity and peak wavelength over millimeter distances. Parallel Raman measurements implicate nanometer-size silicon particles in the photoluminescence mechanism.
Synthesis of Vanadium Oxide Colloidal Dispersions for Antistatic Coatings
Authors: Morrison Eric.D. 
Published: April 2011

AbstractVanadium oxide deposited in thin layers from aqueous colloidal dispersions exhibits electronic conductivity by a small polaron hopping conduction mechanism. Conductivity and static dissipative properties of coatings are unaffected by changes in humidity. Because vanadium oxide is highly colored, the deposition of effective antistatic coatings which are transparent and colorless requires that the percolative (networking forming) properties of the colloidal particles be maximized. The percolative properties of the colloid are strongly influenced by morphology of the dispersed particles and the extent to which they are well dispersed in the aquasol. These properties are determined by the synthetic route to the colloid. Vanadium oxide is the most potent antistatic agent known and has been found to provide antistatic properties even when as little as 1 milligram per square meter is used.
Synthesis of Nanocrystalline Barium-Hexaferrite from Nanocrystalline Goethite Using the Hydrothermal Method: Particle Size Evolution and Magnetic Properties
Authors: Penn R. L. , Banfield J. F. , Voigt J. 
Published: April 2011

AbstractTo characterize particle size/magnetic property relationships, 9 to 50 nm in diameter barium hexaferrite, BaFe12O19 (BHF), particles were prepared using a new synthesis route. By replacing the conventional 50 to 100 nm particles of goethite with nanocrystalline goethite produced via the microwave anneal method of Knight and Sylva [1], nanocrystalline BHF was synthesized using the hydrothermal method. Evolution of particle size and morphology with respect to concentration and heat treatment time is reported. Hysteresis properties, including coercivity (0.2 – 1.0 kOe), magnetization saturation (0.1 – 33.4 emu/g), and magnetization remanence (0.004 – 22.5 emu/g) are discussed as a function of particle size. The magnetization saturation and remanence of the 7 nm particles is nearly zero, suggesting the superparamagnetic threshold size for BHF is around this size. In addition, the equilibrium morphology of BHF crystals was calculated to be truncated hexagonal prisms which was verified by experiment, and the isoelectric point, pH of 4.1, was measured for 18 nm BHF particles.
The Effect of Substrate Type and 2,2′-Bipyridine on the Sorption of Copper(II) on Silica and Alumina
Authors: Cheah Sing-Foong , Brown Gordon E. , Parks George A. 
Published: April 2011

AbstractWe have studied the co-adsorption of Cu(II) and an organic ligand, 2,2′-bipyridine (bipy), on amorphous silica (am-SiO2) and γ-Al2O3 (γ-alumina). This study focuses on two fundamental questions: (1) how bipy affects the macroscopic uptake behavior and molecular-scale characteristics of Cu(II) sorption complexes formed on each oxide; and (2) how and why the uptake behavior and the characteristics of Cu(II) sorption complexes differ for the two oxides. Solution uptake experiments and X-ray Absorption Fine Structure (XAFS) spectroscopy were used to answer these questions.In the absence of bipy and at a surface loading of approximately 0.05 μM/m2, Cu(II) adsorbs predominantly as a dimeric complex on am-SiO2 surfaces but as a monomeric complex on γ-Al2O3. At low Cu(II) to solid ratio, bipy shifts the pH of Cu(II) sorption on am-SiO2 to lower values, but it shifts the pH of Cu(II) sorption on γ-Al2O3 to higher values. Uptake experiments and XAFS measurements on the wet sorption samples indicate that sorption of aqueous Cu(bipy)2 on γ-Al2O3 displaces one bipy from the aqueous Cu(bipy)2 complex, while sorption on am-SiO2 does not disrupt the complex. More detailed XAFS analysis suggests an innersphere Cu(bipy)1 complex on γ-Al2O3 and a stronger Cu-surface oxygen interaction when Cu(bipy)2 adsorbs on γ-Al2O3 than am-SiO2.
Surface Charge Properties Of Kaolinite
Authors: Schroth B.K. , Sposito G. 
Published: April 2011

AbstractThe surface charge components of two Georgia kaolinites of differing degree of crystallinity (KGa-1 and KGa-2) were measured using procedures based on charge balance concepts. Permanent structural charge density (Σ0) was determined by measuring the surface excess of Cs, which is highly selective to permanent charge sites. The values of Σ0 determined were -6.3 ± 0.1 and -13.6 ± 0.5 mmol kg-1 for kaolinites KGa-l and KGa-2, respectively. The net proton surface charge density (σH) was determined as a function of pH by potentiometric titration in 0.01 mol dm-3 LiC1. Correction from apparent to absolute values of ΣH was made by accounting for Al release during dissolution, background ion adsorption, and charge balance. Lithium and Cl adsorption accounted for the remainder of the surface charge components. Changes in surface charge properties with time were measured after mixing times of 1, 3, and 15 hours (the latter representing “equilibrium”). Time-dependent behavior is believed to be caused by mineral dissolution followed by readsorption or precipitation of Al on the mineral surface. Both the point of zero net charge (p.z.n.c.) and the point of zero net proton charge (p.z.n.p.c.) changed with mixing time, generally increasing. The “equilibrium” p.z.n.c. values were approximately 3.6 and 3.3 for KGa-1 and KGa-2, respectively, while the corresponding p.z.n.p.c. values were about 5.0 and 5.4. The p.z.n.c. results were in good agreement with previous studies, but the values of p.z.n.p.c. were higher than other values reported for specimen kaolinite.
Polarization Relaxation in Pzt/Plzt Thin Film Capacitors
Authors: Jiang Bo , Balu Venkatasubramani , Chen Tung-Sheng , Kuah Shao-Hong , Lee Jack C. 
Published: April 2011

AbstractPolarization relaxation in PZT and PLZT (with La concentration from 0% to 10%) thin film capacitors was characterized in the time range from 10 ns to 1000 s. It was found that at zero volt the polarization in PZT and PLZT thin films changes logarithmically with time, P(t) = blog(t) + P0, and the polarization current density J(t) = dP(t)/ dt obeys the Curie-von Schweidler Law, J(t) = b. t−x, with n = 1 from 100 ns extending to 10 s. Over 10 s, the exponent n in the J-t relationship becomes less than 1. The coefficient b in the Q-t and J-t relationship at zero volt correlates strongly with the remanent polarization. La doping in PZT reduces remanent polarization and reduces relaxation.
The Phase Diagram of Epitaxial BaTiO3 Films under Bi-Axial Stress
Authors: Desu S. B. , Chen Z. J. , Dudkevich V. P. , Dudkevich P. V. , Zakharchenko I. N. , Kushlyan G. L. 
Published: April 2011

AbstractThe phase diagram of eptaxial BaTiO3 films in the coordinates of T and αs ( substrate thermal expansion coefficient) is constructed on the basis of the thermodynamic analysis which has been carried out earlier [1]. It is found that two new phase are formed under bi-axial stress. The temperature dependencies of polarization and unit cell parameters for the films on the KTaO3 and SrTiO3 substrates are also calculated.
Thin Films of (Ba, Sr)TiO3 by Aerosol Combustion
Authors: Kussmaul A. , Greenwald A.C. , Wei C.H. , Morse T.F. 
Published: April 2011

AbstractBarium-strontium-titanate (BST) films were deposited on platinum-coated ceramic substrates and platinum foil by the aerosol combustion process. A fine mist of metallic precursors in solution was carried into a methane-oxygen flame to produce ceramic particles, which coated the substrate. Both aqueous and purely organic solutions were tested, the latter producing finer powders (less than 100 nm) with high phase purity. Sintering the as-deposited particulate material led to a porous film at all sintering temperatures studied, regardless of the solution used. Cold pressing of the organicsolution- based material prior to heating, without the addition of any binders or solvents, gave a fully dense solid after sintering at 1450°C.
Epitaxial KnbO3 and Fe-Doped KnbO3 Thin Films Prepared by the Sol-Gel Technique
Authors: Xu Yuhuan , Cheng Chih-Hsing , Mackenzie John D. 
Published: April 2011

AbstractA mixed alkoxide liquid precursor was used to form epitaxial ferroelectric potassium niobate, KNbO3, thin films through the sol-gel technique by carefully designing the solution chemistry and reaction processes. The double alkoxide solution was prepared through hydrolysis and condensation reactions between different metal alkoxides in solution. Fabrication of heteroepitaxial single crystal thin films of KNbO3 deposited on single crystal substrates of MgO and SrTiO3 will be described. Film structure was investigated with X-ray and electron diffraction, and transmission electron microscopy. Second harmonic generation of 1064 nm incident light was demonstrated for KNbO3 thin films in a waveguide configuration. Transient photorefractive gratings in Fe-doped KNbO3 were studied by a two-beam coupling technique for various writing intensities and wavelengths.
Characterization of Pzt Films by Scanning Force Microscopy (SFM)
Authors: Zavala Genaro , Trolier-McKinstry Susan E. , Fendler Janos H. 
Published: April 2011

AbstractScanning Force Microscopy (SFM) has been used for the determination of friction, phase transformation, piezoelectric behavior (contact mode), polarization state and dielectric constant (non contact mode) in several nanometer regions of Lead Zirconate Titanate (PZT) films. The use of the SFM tip, in the contact mode, to polarize different nanoregions of the film and to apply an oscillating field thereon, led to effective piezoelectric coefficients and piezoelectric loops. In the non-contact mode, application of an ac signal (frequency ω) to the tip-electrode system produced an oscillation of the tip at ω (fundamental or first harmonic) and 2ω (second harmonic). The signals ω and 2ω were related to the state of polarization and the dielectric constant of the film. Analysis of the combined contact, non-contact and friction force microscopic data have provided considerable insight into the piezoelectricity and polarization in the nanodomains.
Microstructural Control of RuO2 Electrode and the Related Properties of (Ba, Sr)TiO3 Thin Films
Authors: Choi D.K. , Choi J.Y. , Won J.H. , Paek S.H. 
Published: April 2011

AbstractEffect of microstructure and surface roughness of oxide electrode on the properties of BST films has been investigated. (Ba, Sr)TiO3 and RuO2 films were deposited by RF magnetron sputtering technique. Surface morphology of RuO2 films were controlled by changing the O2/Ar ratio during deposition. It is found that the grain size and surface roughness of BST films are strongly influenced by RuO2 electrode underneath. When the grain size of RuO2 decreased by reducing either O2/Ar ratio during sputtering or film thickness, BST film resulted in fine grain structure and the leakage current decreased due to the improvement in uniformity of the film. Dielectric constant of BST films, however, was decided from both degree of well defined grains and film continuity related to grain size and surface roughness.
Structural Stability of Si-O-a-C:H/Si-a-C:H Layered Systems
Authors: Müller U. , Hauert R. 
Published: April 2011

AbstractAmorphous hydrogenated carbon films are of technological interest as protection coatings due to their special properties such as high hardness, chemical inertness, electrical insulation and infrared transparency. However, some applications still suffer from the poor thermal stability and adhesion problems of these coatings. To ensure good adhesion, especially on hardened steels and non-carbide forming substrates, an extra interlayer has to be deposited first. Often a silicon containing interlayer, Si-a-C:H for example, is used for this purpose. This Si-a-C:H interface layer was deposited by rf plasma deposition from tetramethylsilane. Then a-C:H films containing Si-O with a varying silicon content were produced from a mixture of acetylene and hexamethyldisiloxane. The structural changes upon annealing of these films were investigated using Raman spectroscopy. The analysis of the development of the different peaks upon annealing temperature reveals the transition from the amorphous structure to the more graphitic-like structure. This transition temperature increases by as much as 100°C when silicon is incorporated into the DLC film. However, when Si-O is incorporated instead of only silicon the same increase in temperature stability is observed.
Mechanical Behavior of a Ni/TiC Microlaminate Under Static and Fatigue Loading
Authors: Her Y. C. , Wang P. C. , Yang J.-M. , Bunshah R. F. 
Published: April 2011

AbstractThe mechanical behavior and damage mechanisms of the Ni/TiC microlaminate composites under static and cyclic loading were investigated. The relationship between the ultimate tensile strength and the layer thickness at both room temperature and 600°C was studied. The fatigue life and the evolution of the stiffness reduction under various maximum applied stress levels were determined. The results revealed that the ultimate tensile strength linearly increased as the laminate layer thickness decreased. Also, the microlaminate exhibited a non-progressive fatigue behavior.
Fatigue Behavior of Scs-6/Titanium/Titan1ium Aluminide Hybrid Laminated Composite
Authors: Wang P. C. , Her Y. C. , Yang J. -M. 
Published: April 2011

AbstractThe fatigue behavior of the SCS-6 silicon carbide fiber-reinforced Ti-6Al-4V/Ti-25Al- 10Nb hybrid laminated composite was investigated at room temperature. The accumulation of fatigue damage in the form of matrix cracking was measured as a function of loading cycles and applied stress levels. The residual stiffness and residual tensile strength of the post-fatigued specimens were determined. The comparison of the crack growth behavior of the hybrid composite with both the SCS-6/Ti-6-4 and SCS-6/Ti-25-10 composites will also be discussed.
Microscratch Analysis of The Adhesion Failure on Oxide Thin Films With Different Thickness
Authors: Ottermann C. R. , Bange K. , Braband A. , Haefke H. , Gutmannsbauer W. 
Published: April 2011

AbstractAdhesion failures of Ti2and Ta2O5thin films deposited by reactive evaporation (RE), reactive ion plating (IP) and plasma impulse chemical vapour deposition (PICVD) on fused silica, AF 45, TEMPAX and soda-lime glass substrates are investigated by means of a micro-scratch tester. The oxide films possess thickness between 60 and 500 nm and show different mass densities depending on the deposition conditions. Scratch testing exhibits well pronounced detachment for thicker films on hard substrates. The clearance of the scratch signal is reduced with decreasing layer thickness or for softer substrate materials. The test results are also influenced by the various substrates and different chemical and mechanical properties of the films due to the alternate deposition techniques.
Peel Strength in the Cu/Cr/Polyimide System
Authors: Park I. S. , Yu Jin , Park Y. B. 
Published: April 2011

AbstractIn order to understand the effects of plastic deformation and the interfacial fracture energy on the peel strength, thickness of the metal layer and the pretreatment conditions of polyimide were varied in the Cu/Cr/polyimide system. The work expenditure during the peel test was estimated using the stress strain curves of metal films, X-ray measurements of the plastic strain in the peeled films, and the elastoplastic beam analysis. Results indicate that the peel strength is strongly affected by the film thickness and the pretreatment condition in a synergistic way, and that the measured peel strength is more a measure of the plastic deformation during the peel test than a measure of the true interfacial energy.