bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laser Diagnostics of Microelectronics Fabrication Processes
Authors: Wormhoudt J. , McCurdy K. , Freedman A. 
Published: March 2011

AbstractLaser diagnostics, including long path infrared diode laser absorption and dye laser induced fluorescence, are able to provide microscopic information on the gas phase of such important semiconductor fabrication processes as plasma etching and plasma enhanced deposition. It is possible to measure temperatures, concentration profiles, and absolute concentrations if independent laboratory measurements of quantitative spectroscopic parameters have been made. Infrared band strength measurements on several molecular radicals important in semiconductor processing systems are described. We also describe a new apparatus which allows multipass absorption and laser induced fluorescence diagnostics of a large volume of plasma.
Irradiation Effects on the Interfacial Adhesion Between Ti Films and SiO2 Substrate
Authors: Cheng Guoan , Liu Baixin , Li Hengde 
Published: March 2011

AbstractThe interfacial adhesion of Ti films on SiO2 substrate was studied by room temperature argon ion irradiation. Range of ion energy was chosen from 100 to 300 keV. Adhesive strength was measured by scratching test. For Ti/SiO2 pair irradiated by 100 keV argon ions, the adhesion was easier to enhance and much greater strength was obtained than that irradiated by 300 keV argon ions. The threshold dose also increased with the increasing of ion energy. The adhesive strength and the threshold dose increased when the metallizing temperatures were higher. Rutherford backscattering spectra(RBS) showed that a transition layer of about 10 nm thick was formed in Ti/SiO2 interface region after irradiation to a dose of 5X1016 Ar/cm2, indicating some chemical reaction has probably taken place. The experimental results are discussed in terms of thermodynamics of solids.
Improved Adhesion for SiO2 Particles on Silica Substrates using Helium-Ion Irradiation
Authors: Musket R. G. , Thomas I. M. 
Published: March 2011

AbstractWe have examined the effects of irradiation with 200 keV helium ions on the adhesion and optical transmission properties of 220 nm thick antireflective, optical coatings that consisted of layers of spherical, 20 nm diameter silica particles. In the as-deposited state these sol-gel coatings have very low adhesion to the fused silica subtrates. Results for adhesion and optical transmission have been obtained for doses of 1013–1017 He/cm2. Significant improvement in adhesion was found for doses exceeding about 2×1014 He/cm2. Optical transmission measurements for wavelengths of 200–1200 nm showed increasing absorption with dose. We have evidence that the helium ions decompose various contaminants in the coating into two types of degradation products. One is volatile and the other remains in the coating as optically absorbing species. UV/oxidative-gas treatment effectively removes the absorbing species.
Residual Stress, Fracture, and Adhesion in Sputter-Deposited Molybdenum Films
Authors: Mattox D. M. , Cuthrell R. E. 
Published: March 2011

AbstractAtomistically deposited films may form with high residual stresses which may be either tensile or compressive in nature. These film stresses represent stored strain energy which may affect the adhesion of the film-substrate couple and in the limit may cause spontaneous fracture at or near the film-substrate interface (loss of adhesion). In the post cathode magnetron sputter deposition of molybdenum films, we have found that the intrinsic film stresses are generally anisotropic and may easily exceed the fracture or adhesive strength of the film-substrate couple. The residual stress anisotropy in the film is dependent on the orientation with respect to the post cathode and the magnitude and nature of the stresses are very dependent on the deposition conditions, particularly gas pressure during sputtering. By using a pressure-cycling technique, we have deposited thick (5 microns) films of molybdenum which have little residual stress or stress anisotropy.
Quantitative Study of Al/W Interaction In Si/SiO2/W-Ti/Al Thin Film System
Authors: Liu Hung-Yu , Chang Peng-Heng , Bohlman Jim , Tsai Hun-Lian 
Published: March 2011

AbstractThe interaction of Al and W in the Si/SiO2/W-Ti/Al thin film system is studied quantitatively by glancing angle x-ray diffraction. The formation of Al-W compounds due to annealing is monitored by the variation of the integrated intensity from a few x-ray diffraction peaks of the corresponding compounds. The annealing was conducted at 400°C, 450°C and 500°C from 1 hour to 300 hours. The kinetics of compound formation is determined using x-ray diffraction data and verified by TEM observations. We will also show the correlation of the compound formation to the change of the electrical properties of these films.
Metal-Ceramic Interfacial Reactions: The Copper-Cordierite and Titanium-Cordierite Systems.
Authors: Bortz M. , Ohuchi F. S. 
Published: March 2011

AbstractInterfacial reactions between either copper or titanium and cordierite-based (2MgO.2Al2O3.5SiO2) ceramic substrates are probed using X-ray Photoelectron Spectroscopy (XPS). Room temperature reactions are found to be strongly dependent on interfacial chemistry; while copper reacts weakly with the cordierite surface, titanium strongly reduces the Si-O and Al-O substrate bonds. Behavior during subsequent “in situ” annealing is dependent on substrate morphology. On amorphous cordierite films copper remains nonreactive while titanium dissociates remaining Si-O and Al-O bonds, forming a low valency Ti1+ oxide. On crystalline cordierite substrates copper diffuses rapidly upon annealing while titanium reduces substrate bonds forming a high valency Ti3+ oxide. Furthermore, thin 5Å Ti interlayers prevent copper diffusion at temperatures below 650°C. This study represents the first comprehensive treatment of the interfacial reactions in metal-multicomponent ceramic systems.
Quantitative Studies of the Effect of Adhesion on the Mechanical and Physical Properties of Polymer Composites
Authors: Williams J. W. , Shang S. W. , Sacks M. D. 
Published: March 2011

AbstractYoung's modulus, tensile strength and the storage shear modulus experiments were performed on silica-filled ethylene-vinyl acetate composites and the results were correlated with polymer-filler interaction energy. The polymer-filler interaction energy was determined by wetting and infrared spectroscopy experiments. The interaction energy was characterized by the work of adhesion. The results indicate there is a strong correlation between modulus and tensile strength and the work of adhesion. There was an exponential relationship of modulus and tensile strength with the reciprocal of the work of adhesion.
Ion-Implantation of Reactive Elements in Improving the Adhesion of Thermally Grown Cr2O3 Sales
Authors: Hou P. Y. , Stringer J. 
Published: March 2011

AbstractThe high temperature oxidation behavior of Al, Y and Hf ion-implantation in Ni-25wtCr alloy with dosages ranging from 1015-1017 ions/cm2 has been studied. Results are compared with the unimplanted alloy, a Xe-implanted alloy and alloys with 0.2wt% Y or lwt% Al additions. Oxidation tests were carried out at 1000°C and 1100°C in 1 atm. O2. It is found that the ion-implantation of Y and Hf greatly reduced oxidation rate and improved scale adherence after a critical implantation dosage, ∼ l×1016 ions/cm2, has been reached. The improved scale adhesion is attributed to both a reduction in growth stress and a strengthened scale/alloy interface, which all developed as a result of a modified scale growth process.
The Adherence of Nickel Oxide on Nickel During High-Temperature Oxidation
Authors: Liu Yung Y. , Natesan K. 
Published: March 2011

AbstractA combined experimental/analytical study is being conducted to investigate the fundamental nature of adherence of oxide scales formed on metals during high-temperature oxidation. Isothermal oxidation experiments were conducted on high-purity nickel (Ni 270) specimens in air at temperatures of up to 1200°C. None of the experiments resulted in physical separation of nickel oxide scales from the nickel substrate, even though substantial amounts of porosity were found in scales close to the scale/matal interfaces. The results of numerical and analytical calculations of stresses in the NiO/Ni system suggest that metal and oxide plasticities play a role in the experimental observations.
Enhancing Mechanical Properties of Polymer Composites by Modification of Surface Acidity or Basicity of Fillers
Authors: Fowkes F. M. , Dwight D. W. , Manson J. A. , Lloyd T. B. , Tischler D. O. , Shah B. A. 
Published: March 2011

AbstractThe surface of a powdered glass has been treated to optimize its performance as a filler in polymer composites cast from solution. The aim has been to enhance acid-base interactions between the functional sites of polymers and the surface sites of the glass particles so as to insure complete coverage of the glass particles by adsorbed polymer molecules, and to thereby enhance both the adhesion and dispersion of the filler. The glass chosen for this study is a magnesium aluminum silicate of very low alkali metal content, and its surface sites have negligible basicity and only moderate acidity, as evidenced by weak adsorption of polymethylmethacrylate and negligible adsorption of chlorinated polyvinylchloride from solution in methylene chloride. Because of the negligible surface basicity of the filler, acidic polymers such as polyvinylbutyral and polyvinyl chloride are not adsorbed sufficiently to promote adhesion or dispersibility, and brittle or weak composites result.Surface treatments to enhance surface acidity or basicity of the glass particles were evaluated by electrophoresis in organic solvents, in which acidic particles had negative zeta-potentials and basic particles had positive zeta-potentials; untreated glass particles had zero zetapotentials. The most effective treatments were done with silane coupling agents; amino-silanes provided strong negative zeta-potentials and methacryloxy-silanes provided strong positive zeta-potentials. Angleresolved ESCA spectra showed that the adsorbed amino-silanes averaged about a monolayer in thickness and that half of the nitrogens bonded to the surface as ammonium groups and half were in the outer surface as basic amine groups; the carbonyl oxygens of the methacryloxy-silanes appeared to be bonded to the surface.Heavily-loaded polymer composites were made with the silane-treated and with untreated glass powders, using two acidic binders and a basic binder. The acidic binders were a polyvinylbutyral (PVB) binder cast from solution in a methanol-MIBK mixture, and a post-chlorinated polyvinylchloride (CPVC) binder cast from solution in a mixture of cyclohexane and tetrahydrofuran (THF): the glass transition temperature (Tg) for CPVC is about 140 C, but for PVB it is only about 35 C. The basic polymer (PEHM, polyethyl-hexylmethacrylate) has a Tg well below room temperature. Thus the extension to break in tensile tests was about 1% for CPVC, 10% for PVB, and 20 % for PEHM. About ten stress-strain Instron tests were made on each composite, and the composites with appreciable acid-base interactions between the matrix polymer and the surface sites of the treated glass fillers were in all cases much tougher than those without such acid-base interactions. The brittleness of the polyvinylbutyral composites filled with untreated glass powders was not observed at all on silane-treated glass powders.
On the Modifiection of Polyethyleneterephtplgte Surfaces to Improve Pohesion
Authors: Occhiello E. , Gprbassi F. , Morini G. 
Published: March 2011

AbstractThe adhesive properties of PET have been enhanced by treatments with alkaline solutions and CF4/02 plasmas. Alkaline solution induce hydrolysis of the polyester and etching, with consequent strong roughening of the surface. Adhesion siemed more related to etching than to surface chemistry modifications, suggesting a prominent role of mechanical interlocking.CF4/02 plasmas did not induce significant etching, but the surface chemistry was strongly altered. Ester bridges were effectively removed by the plasma, high oxygen mixtures destroyed aromatic rings and introduced oxygen by the
hydroperoxide mechanism. Adhesion was worsened by the introduction of fluorocarbon radicals by Low oxygen discharges. The most effective enhancement was obtained with the 30 % discharge, where the aromatic rings are still quite intact, while ester bridges are removed with formation of phenolic end groups.
Polylmide Adhesion as a Function of Substrate Structure
Authors: Mil Jan Van , Helms Aubrey 
Published: March 2011

AbstractWe have investigated the effect of different inorganic substrates on the adhesion of polymer films. We have used crystalline surfaces in an effort to “map” the adhesive interactions that take place through the interface between substrate and polyimide (-arnic acid). Significant differences were found in the adhesion of polyimide films (as measured by peel tests) on substrates varying only in crystalline orientation. Detailed analytical investigations are reported of the interfaces of these substrates after peeling of the film, using angular dependent ESCA. A correlation was found between the chemical nature of the substrate and the adhesion quality. This correlation involves the crystalline matrix of the substrate surface.
Characterization of Plasma-Fluorinated Polypropylene and Polystyrene Surfaces by Static Sims
Authors: Van Ooij W. J. , Michael R. S. 
Published: March 2011

AbstractStatic SIMS was used to characterize polypropylene and polystyrene films following exposure to SF 6 and C2F 6 plasmas. The predominant species which are incorporated into the polymer surfaces are fluorine atoms and CF 2 /CF 3 radicals, respectively.
Electron Microscope Observations of Mechanisms of thin Film Delamination from Substrates
Authors: Goyal D. , King A. H. 
Published: March 2011

AbstractTransmission electron microscope techniques have been applied to the problem of thin film delamination from substrates during film formation. Model systems involving metal films on single crystal silicon substrates have been used and it is found that delamination of the films is initiated by the formation of damage in the substrate. This understanding removes some of the fundamental problems regarding delamination.
Mechanics of the Peel Test for Thin Film Adhesion
Authors: Kim K-S. 
Published: March 2011

AbstractThe mechanics aspects of the peel test are analyzed. In this analysis, the limitation and applicability of the peel test for thin film adhesion have been investigated. Firstly, the effect of plasticity in the peel test of thin metallic films is analyzed. The analysis has given a closed form solution for the partitioning of peel strength between the energy expenditure rate for the decohesion process and the internal work expenditure rate caused by plastic deformation (bending) of the film. The results predicted the variation of peel strength as a function of the film thickness, the film yield stress and the compliance of the substrate. This analysis shows that the peel strength is very sensitive to the thickness of the film and the yield stress of the film. As observed in the experiment, the peel strength has a peak value at a certain thickness of the film. This is explained for both L and T peel tests. Unlike the L peel test, the peak phenomenon in the T peel test (of metallic films) is due to the hardening of the adhered film. Secondly, the effect of plasticity and viscoelasticity in the peel test of thin polymer films is analyzed. Unlike the peel test of metallic films, tension and shear effect of the film deformation is very important in the analysis of the polymer peel test. An integral equation is formulated for the viscoelastic models of the adhered film. The solution of the integral equation reveals the important parameters in polymer peeling and their contribution to the peel force as well as to the viscoelastic dissipation. In addition, the meaning of the interface toughness is reexamined and the interface toughness is evaluated by the peel test. Based on these analyses, a Universal Peel Diagram has been constructed, which accounts for the hardening behavior of the film. On this diagram, objective interfacial decohesion toughness can be readily obtained using very simple peel tests. The analysis includes not only the 900° peel test but also the general angle peel test. Comparison between the theory and experiment has been made with the experimental data provided by J. Kim of IBM. The comparison shows good agreement.
Mechanical Properties Of Cu-Based Composites with in Situ Formed Ultrafine Filaments
Authors: Bevk J. , Sunder W. A. , Dublon G. , Cohen David E. 
Published: March 2011

ABSTRACTElastic and plastic properties of in situ Cu-based composites with Nb, V, and Fe filaments are reviewed. The evidence is presented for a pronounced size dependence of both the ultimate tensile strength and the Young's moduli. In composites with the smallest filaments (d∼50–200Å) and filament densities as high as 1010/cm2 dislocation density reaches values of 1013 cm/cm3. The yield stress of these samples increases dramatically over the predictions based on the “rule of mixtures” and their ultimate tensile strength approaches the estimated theoretical strength of the material (∼2.7GPa). The observed decrease of Young's modulus as a function of inverse wire diameter in the as-drawn composites is attributed to lattice softening due to high density of extended lattice defects. Upon annealing, Young's modulus increases by as much as 100% and exceeds the maximum values calculated from bulk elastic constants. Possible mechanisms leading to modulus enhancement and to related changes in magnetic and superconducting behavior of in situ composites are discussed.
The Growth of Submicron Eutectic Thin Film Structures
Authors: Cline Harvey E. 
Published: March 2011

AbstractAs the minimum dimension of electronic circuits is reduced below one micron, there has been increased interest in developing techniques for fabricating submicron structures. Pb-Sn, Cd-Pb and Al-Al 2Cu eutectic thin films were directionally solidified at rates between .0015 cm/sec and .15 cm/sec with both a lamp and a laser heat source to fabricate fault free submicron periodic structures. A transition from lamellar to cellular structures with increasing solidification rate was observed with a thermal gradient of 200°C/cm applied with the lamp heat source. Cells did not form with the increased thermal gradient produced by the laser heat source, 8000° C/cm. Spacings as fine as .1 micron were observed in the Cd-Pb eutectic. A maximum theoretical growth rate was estimated which corresponds to a spacing of 80A.
In Situ Electron Microscopy : Solidification of Eutectic Alloys.
Authors: Lemaignan Clément , Pélissier Joseph 
Published: March 2011

A heating stage and an advanced video recording system were used in the 1 MeV electron microscope of CEN Grenoble. This allowed us to observe various aspects of eutectic solidification. These observations include regular lamellar solidification with faceted or non faceted solid-liquid interfaces, change of lamellar spacing with solidification rate, non reciprocal heterogeneous nucleation of eutectic solidification.We discuss them with respect to the classical theories and introduce a new eutectic nucleation mechanism based on surface dendrites.
Mechanical And Superconducting Properties Of Cu-Nb3Sn In Situ Produced Composite Wires
Authors: Kolb-Telieps A. , Mordike B.L. , Mrowiec M. 
Published: March 2011

ABSTRACTCu-Nb composite wires were produced from powder, electrolytically coated with tin and annealed to convert the Nb fibres to Nb 3Sn. The content was varied between 10 wt % and 40 wt %. The superconducting properties of the wires were determined. The mechanical properties, tensile strength, yield strength and ductility were measured as a function of volume fraction and deformation over a wide temperature range. The results are compared with those for wires produced by different techniques.
Fatigue Crack Growth in Co and Ni Base Directionally Solidified Eutectic Composites
Authors: Hoffmann C. , Bhowal P. , Mcevily A. J. 
Published: March 2011

AbstractA study of fatigue crack growth behavior in four directionally solidified eutectic composites has been carried out in air at room temperature and at 870°C (1600 °F). The alloys investigated included two cobalt-base alloys, CoTaC and CoTaC+Cr, and two nickel base alloys, γ′-Mo and γ/γ′-δ. Fatigue crack growth was studied in directions parallel and perpendicular to the solidification direction. It was found that the addition of chromium to the CoTaC alloy strengthened the interface and promoted trans-fiber crack growth. In addition, the effect of interlamellar spacing on the rate of fatigue crack growth was examined for the γ/γ′-δ alloy. A reduction in interlamellar spacing reduced the crack growth rate. The growth rates are related to the corresponding stress intensity factors and are discussed in the light of prior investigations reported in the literature.
Microstructural Effects on Ductile Phase Toughening of Nb-Nb Silicide Composites
Authors: Lewandowski J. J. , Dimiduk D. , Kerr W. , Mendiratta M. G. 
Published: March 2011

AbstractIn the Nb-Si system, the terminal Nb5 Si3 phase and the Nb Si phase are virtually immiscible up to approximately 2033K. This system offers the potential of producing composites consisting of a ductile refractory metal phase and a strong intermetallic phase. In-situ composites containing different volume fractions of the ductile Nb phase were produced via vacuum arc-casting. Microhardness testing as well as smooth bend bar testing was conducted at temperatures ranging from 298K to 1673K in an attempt to determine microstructural effects on the yield strength and smooth bar fracture strength. Notched bend specimens were similarly tested to determine the effects of the ductile phase (i.e. Nb) on enhancing the notched bend toughness. It is shown that the Nb phase often behaves in a ductile manner during testing, thereby toughening the in-situ composite. The mechanism of toughening appears to be due to crack bridging.
Fracture behavior of 3-d Braided Nicalon/Silicon Carbide Composite
Authors: Yang J.-M. , Chou J.-C. , Burkland C. V. 
Published: March 2011

AbstractThe fracture behavior of a 3-D braided Nicalon fiber-reinforced SiC matrix composite processed by chemical vapor infiltration (CVI) has been investigated. The fracture toughness and thermal shock resistance under various thermomechanical loadings have been characterized. The results obtained indicate that a tough and durable structural ceramic composite can be achieved through the combination of 3-D fiber architecture and the low temperature CVI processing.
Suspension Processing of SiC Whisker-Reinforced Composites
Authors: Sacks Michael D. , Lee Hae-Weon , Rojas Oswaldo E. 
Published: March 2011

AbstractSuspension processing was used to prepare Al2O3 /SiC whisker and Al2O3/ZrO2 /SiC whisker compacts with high green density, fine pore sizes, and homogeneous microstructure. Procedures for optimizing particle/whisker co-dispersion and subsequent consolidation by slip casting are reviewed. Compacts prepared by slip casting showed significantly higher sintered densities compared to dry-pressed samples.
The Mechanical Properties at High Temperatures of SiC Whisker-Reinforced Alumina
Authors: Xia Kenong , Langdon Terence G. 
Published: March 2011

AbstractCreep tests were conducted at temperatures from 1673 to 1823 K on samples of Al2O3 containing 9.3, 18 and 30 vol % SiC whiskers. The results show that the strains to failure tend to decrease and the stress exponents for the steady-state creep rates tend to increase with increasing volume percentages of SiC whiskers.