bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adhesion Promotion by Surface-Modification at the Pmma-Metal Interface for Liga-Type Processing
Authors: Das S. S , Malek C. G.Khan 
Published: April 2011

AbstractThe formation of high aspect ratio Micro-Electro-Mechanical Structures (HI-MEMS) requires good adhesion of the thick microstructures to the substrate. The interfacial bond strength between PMMA and various metal substrates (Ti, Cu, Au, and Ni), in the preliminary stages of the LIGA process, was evaluated by shear stress measurement. Adhesion promotion processes have been investigated such as texturing of the surface of Ti and Cu substrates by chemical oxidation or thermal processing of the PMMA sheet, and use of a positive resist as an interfacial adhesion promoter. Several fold increases in bond strength were obtained, the largest increase associated with a combination of substrate roughening, thermal treatment and use of adhesion promoters.
Mechanical Property Evaluation of Electroplated High Aspect Ratio Microstructures
Authors: Stephens L. S. , Kelly K.W. , Meletis E.I. , Simhadri S. 
Published: April 2011

AbstractHigh aspect ratio microstructures (HARMs) with a height of hundreds of micrometers and a width of a few tens of micrometers present high promise in a number of challenging fields. At LSU, a number of applications are being developed in which nickel HARMs are electroplated on metal surfaces (mold insert fabrication for the LIGA process, HARMs on mechanical seal faces, HARMs on heat exchange surfaces, etc.). In some of these applications, the HARMs are subjected to high stresses and the mechanical properties are particularly important. These properties can be used to adjust processing parameters to optimize properties of the HARMS.This paper presents a method for measuring the strength properties of cantilevered nickel HARMs constructed by LIGA. Experimentally measured values are reported for modulus of rupture (1280 MPa), Young's modulus (153 GPa) and Knoop hardness (500 Hk) for HARMs with an overplated base. SEM micrographs clearly indicate that failure of the beams is brittle and most frequently occurs at the interface of the beam and overplated base.
Fracture Strength of Polycrystalline Silicon
Authors: Jonestt P.T. , Johnsontt G.C. , Howe R.T. 
Published: April 2011

AbstractA structure has been developed to measure the fracture strength of thin films that allows for a large amount of statistical data to be generated from a single die. The strength of a material is determined by measuring the displacement at fracture of cantilever beams bending in-plane. This device has been used to measure the fracture strain of three different polysilicon materials: polysilicon from two different MCNC MUMPS runs and a polysilicon fabricated at the Microfabrication Laboratory at the University of California at Berkeley. The strain at fracture of the MUMPS polysilicon was measured to be 1.5% ± 0.2% for both MCNC MUMPS runs. The Berkeley polysilicon exhibited a fracture strength of 1.2% ± 0.1%, a difference from the MUMPS result that is statistically significant. Also, no statistical difference in fracture strength was measured on specimens that were super-critically carbon dioxide dried as opposed to furnace dried. In a separate experiment, the Young's modulus of the MCNC MUMPS polysilicon was found to be 173 ± 20 GPa.
Young's Modulus, Yield Strength and Fracture Strength of Microelements Determined by Tensile Testing
Authors: Greek S. , Ericson F. 
Published: April 2011

AbstractSome mechanical properties of thin film microelements, e.g. fracture strength, depend on the manufacturing process, the load application as well as on size and shape of the microelements. Hence, the test structures that are used to determine mechanical properties should have dimensions of the same order of magnitude as an application structure, i.e. microelements must be used to accurately characterise MEMS. The fabrication of test structures must be realised in the same process as an intended application in order to give accurate results. Microelements are easily viewed in an SEM, but to be handled and tested in situ a micromanipulator was developed. Test structures were designed as released beams fixed to the substrate at one end, with a ring at the other. A high-precision testing unit was mounted on the micromanipulator next to the test structures. In the SEM, the testing unit was manoeuvred to grip the ring of the test structure beam and a tensile test of the beam was then executed. From the test data Young's modulus and fracture strength of polysilicon and single crystalline silicon were evaluated. Relative measurement of test structures with different beam lengths enabled Young's modulus to be evaluated with an accuracy of ±5%. Young's modulus was determined to 172±7 GPa for polysilicon and 142±9 GPa for single crystalline silicon in the <100> direction. The fracture surfaces were examined and compared. Young's modulus, yield strength and fracture strength of microelements made from electroplated nickel and nickel-iron alloy were also measured. Young's modulus was evaluated to 231±12 GPa for nickel and 155±8 GPa for nickel-iron alloy composed of 72 at% nickel and 28 at% iron.
Meso (Intermediate)-Scale Electromechanical Systems for the Measurement and Control of Sagging in LtcC Structures
Authors: Espinoza-Vallejos Patricio , Zhong Jihua , Gongora-Rubio M. , Sola-Laguna Luis , Santiago-Aviles J.J. 
Published: April 2011

AbstractSagging of suspended or laminated structures is a common problem in the processing of Low Temperature Co-Fired Ceramics (LTCC). These glass-ceramic composites are susceptible to plastic deformation upon lamination, or under the stress of body forces once the glass transition temperature of the glass binder is reached during processing. We have designed and fabricated, using the conventional methods of LTCC fabrication, meso-scale structures (ranging in size from 100 mm to 1 cm) to quantify and seek control strategies for this problem. We have implemented bridge structures and membranes to emulate most of the conventional structures encountered during packaging or sensor (actuator) device fabrication.We have observed that when an LTCC tape with holes larger than 400 µm in diameter is laminated, the tapes above and below deform into the cavity. For smaller diameters, deformation is negligible. Bridging structures can be compensated for the potential effect of body forces by screen-printing a thick film over-layer which exert internal tensile stresses on sintering. This can often yield straight bridges. The use of fugitive phase materials, which disappear or flow during firing, is another way of supporting bridging structures. Several of these strategies have been explored, and results are presented.
Bioencapsulation in Sol-Gel Glasses
Authors: Bergogne L. , Fennouh S. , Livage J. , Roux C. 
Published: April 2011

AbstractBioencapsulation in sol-gel materials has been widely studied during the past decade. Trapped species appear to retain their bioactivity in the porous silica matrix. Small analytes can diffuse through the pores allowing bioreactions to be performed in-situ, inside the sol-gel glass. A wide range of biomolecules and micro-organisms have been encapsulated. The catalytic activity of enzymes is used for the realization of biosensors or bioreactors. Antibody-antigen recognition has been shown to be feasible within sol-gel matrices. Trapped antibodies bind specifically the corresponding haptens and can be used for the detection of traces of chemicals. Even whole cells are now encapsulated without any alteration of their cellular organization. They can be used for the production of chemicals or as antigens for immunoassays.
Design and Synthesis of Vanadium Pentoxide/Polypyrrole Hybrid Electrochemical Materials
Authors: Harreld J.H. , Dunn B. , Cheng W. , Leroux F. , Nazar L.F. 
Published: April 2011

AbstractVanadium oxide/polypyrrole hybrid gels were synthesized by two different strategies. These approaches were focused on either the sequential or consecutive polymerization of the inorganic and organic networks. Both techniques led to monolithic hybrid aerogels. Aerogels synthesized by the consecutive network formation method (“cosynthesis”) with compositions of approximately [PPy]0.8V205intercalated nearly twice as much Li per V2O5(2·8·3·0 Li/V205) as non-hybridized V20, aerogel (1·5 Li/V205). When suitable oxidation and polymerization treatments were applied to the materials, their specific capacity remained reasonably high (180−190 mAh/g compared to 220 mAh/g exhibited by V205, aerogel).
Hybrid Gels and Nanoscale Chemistry for Optical Applications
Authors: Boilot J-P. , Biteau J. , Brun A. , Chaput F. , Morais T. Dantas De , Darracq B. , Gacoin T. , Lahlil K. , Lehn J-M. , Levy Y. , Malier L. , Tsivgoulis G-M. 
Published: April 2011

AbstractA large variety of materials for optical and optoelectronic applications has been developed by trapping active organic molecules and nanocrystals into pure inorganic and hybrid organic- inorganic gels. Concerning optically active molecules, we focus only here on luminescent materials for solid state tunable lasers and light-emitting diodes, and photochromic materials for integrated optics and optical storage. Optical properties can be controlled by changing the nature and the intensity of chemical and steric interactions between the organic system and the solid host matrix. Concerning nanocrystals, we present two approaches for the synthesis of transparent solids based on 1I-VI semiconducting nanoparticles. A first category of materials consists in the dispersion of CdS nanoparticles in sol-gel silica matrices. The luminescence can be controlled by offering an alternative pathway for the recombination of surface trapped carriers. A second group of transparent materials is obtained by considering the CdS nanoparticles not only as the optically active units, but also as the building blocks for the whole solid.
α-RuCl3: A New Host for Polymer Intercalation. Lamellar Polymer/α-RuCI3 Nanocomposites.
Authors: Wang Lei , Brazis Paul , Rocci Melissa , Kannewurf Carl R. , Kanatzidis Mercouri G. , Claflin B. , Lucovsky G. , Claflin B. , Lucovsky G. 
Published: April 2011

Abstractα-RuCl3 was identified as a new host for polymer intercalation using different intercalative methods. It is found that Li0.2RuCl3 exfoliates in water into single [RuCl3]x− layers which can be used to encapsulate macromolecules. RuC13/polymer nanocomposites such as Li0.2(PEO)xRuCl3 (PEO=poly[ethylene oxide]), Li0.2(PVP)xRuCl3 (PVP=polyvinylpyrrolidone) and (PPY)xRuCl3 (PPY=polypyrrole) were successfully prepared. (PANI)xRuCl3 (PANI=polyaniline) was prepared by in situ intercalative polymerization directly from α-RuCl3. These nanocomposites were characterized with Thermogravimetric Analysis (TGA), Infrared spectroscopy (IR), Powder X-ray Diffraction (XRD), magnetic measurements, conductivity measurements and thermopower measurements.
Liquid, Methoxylated Polysiloxane / Silica Hybrid Resins by a Non-Hydrolytic Route
Authors: Bourget L. , Mutin P.H. , Vioux A. 
Published: April 2011

AbstractThe preparation of liquid, methoxylated, polysiloxane hybrid resins containing Me2Si(O-)2 (D) or MeHSi(O-)2 (DH) units cross-linked by Si(O-)4 (Q) units was attempted using the nonhydrolytic condensation reaction between Si-Cl and Si-OMe groups, catalyzed by ZrCI4. The structure of the resins was investigated by 29Si NMR, which showed that redistribution reactions played a prominent role. Thus, Si-OMe/Si-OSi redistributions lead to a highly homogeneous, random structure for the D/Q resin. On the other hand, this route does not apply to the synthesis of DH/Q resins, due to the redistribution of Si-H bonds which leads to the escape of MeSiH3 and to the formation of T and TH units.
Shape-Controlled Synthesis of Hydroxyapatite in Organic Media
Authors: Sakamoto K. , Nakahira A. , Okazaki M. , Ichihara J. , Inoue M. , Yamaguchi S. 
Published: April 2011

AbstractWe have examined the effect of organic solvent on the microstructures of hydroxyapatite (HAp) formed by hydrolysis of α -tricalcium phosphate ( α -TCP) in heterogeneous solvent system (water-hydrophobic organic solvent). The shape of HAp was like ultrafine whisker (length : about 1 ∼- 4 µ m) and its size depended on the used organic solvent.As a simple hybridization, incorporation of fluoride anion (F−) into HAp was attempted in similar system to obtain fluoridated apatite [Ca10(PO4)6(OH)2−x Fx.]. The formation rate was strongly affected by the concentration of F− and reaction temperature. Although the product in water (in the absence of organic solvent) consists of fine particles less than 1 µ m, the product prepared in the heterogeneous solvent system was mixture of ultrafine particles ( ∼ 0.1 µ m) and needle-like particles (length : about 1 ∼ 4 µ m, width : ∼ 0.5 µ m). The microstructures of HAp and FHAp were controlled by hydrophobicity of organic solvent.
Synthesis of Oriented Meso-Structure Silica Film by Ferrocenyl Surfactant
Authors: Zhou H.S. , Honma I. 
Published: April 2011

AbstractSelf-assembly of organic-inorganic molecules into highly order nanostructured architectures have attracted increasing attention because these materials provide a rich source for scientific research and technological applications. We report the synthesis of an oriented silica mesostructured film by ferrocenyl surfactant templating using a spin coating method. The oriented silica meso-structure film was prepared as follows: tetraethoxysilane (TEOS) was partially hydrolyzed by a substoichiometric amount of pure water mixed with ethanol (EtOH) under acidic condition. The solution became homogeneous as the hydrolysis proceeded, then, ferrocenyl TMA was added, the mixture was stirred at room temperature for about 1 hour, and finally, the film was obtained by spin coating the hybrid sol. X-ray diffraction pattern of the film showed that the film oriented in a lamellar structure with (100) d-space of 36.3 A. The optical and electronic conductivity properties of the film have also been explored.
Analysis of Layered Structures at High Spatial Resolution Using Energy Filtered Imaging
Authors: Flaitz P.L. , Bruley J. 
Published: April 2011

AbstractThe development of energy filtered imaging systems for the TEM has opened new approaches to analyzing structures with very small dimensions. One of the benefits of such systems is the ability to form an EELS spectrum image containing energy information on one axis and spatial information on the other axis. By dissecting such an image in the spatial dimension, it is possible to generate a line profile across a layered structure at high spatial dimension without the need for a small probe. We have applied this approach to two structures typical of semiconductors, the Si/SiO2/Si interfaces in a gate oxide and the Ti/SiO2 interface for Al barrier metallization, which illustrate the spatial resolution possible with this technique. To analyze the spectrum images, the element specific near edge structure (ELNES) data are processed by conventional EELS background routines and multivariate statistical techniques using MATLAB software to extract both profiles of principal bonding components and composition.
Applications of High Resolution Immersion Lens Scanning Electron Microscopes to Sem-Based Defect Review at 250nm Design Rules
Authors: Tracy B. 
Published: April 2011

IntroductionThe use of SEM-based defect review tools has increased dramatically over the past five years as the semiconductor industry moved from 0.7 micron to 0.25 micron design rules. During this period, a dramatic inflection occurred at the 0.5 micron node; optical microscopy lacked sufficient resolution to determine even if a simple etch step was properly performed. Accordingly, many “inspection SEMs” were introduced into the wafer fabrication facility. With ever increasing focus on yield improvement, defect review SEM's proliferated in the fab in an effort to drive down both baseline defects and process excursions. In order for such an effort to be successful, a clear improvement in the low voltage image resolution performance of the scanning electron microscope was required. Commercial vendors have responded with impressive tools achieving image resolutions of 2.5–4nm @1 kV. At this level of performance, routine observation of semiconductor wafers is possible at 100,000X magnification. This dramatic improvement in resolution is the result of many factors, by far the biggest of which is the use of “immersion lens” designs which employ a strongly excited objective lens operated at short working distances (∼2mm). This electron optic design was first introduced into the laboratory SEM market, with instruments capable of producing approximately 1.2nm resolution at 20kV. These high performance lenses in which the magnetic field extends below the bottom of the polepiece, were fitted onto 200mm platforms allowing whole wafer inspection/defect review. The features of such tools and their application to the IC industry is the subject of this paper. An example of the superb imaging performance of such a 200mm tool is illustrated in figure 1.
The Effect of Growth Temperature and Substrate Misorientation on Degree of Order and Antiphase Domain Size in Ga0.52In0.48P Epilayers Grown on GaAs (001) Substrates by Gs-Mbe
Authors: Meenakarn C. , Staton-bevan A. E. , Najda S. P. , Duggan G. , Kean A. H. 
Published: April 2011

AbstractA Transmission Electron Microscopy (TEM), Photoluminescence (PL) and Photoluminescence Excitation Spectroscopy (PLE) investigation has been conducted on Ga0.52In0.48P epilayers grown on (001) GaAs substrates by Gas-Source Molecular Beam Epitaxy.For Ga0.52In0.48P epilayers grown on exact (001) GaAs substrates, increasing the growth temperature from 480°C to 535°C increased the antiphase domain plate thickness, t, from 7.3±0.4 to 17.4±0.9 Å, and decreased the long range order parameter, n, from 0.32 to 0.18±0.1. For epilayers grown at 530°C, on GaAs(001) substrates off-cut 0°, 7°, 10° and 15° towards [111]A, increasing the substrate misorientation from 0° to 15° decreased the antiphase domain plate thickness, from 12.3±0.6 to 6.0±0.3 Å. The long range order parameter also decreased from 0.19 to 0.10±0.01.The band gap energies of these samples, grown by GS-MBE, were close to those reported
for fully disordered Ga0.52In0.48P epilayers grown by MOCVD at ∼760°C. This shows that GSMBE is also a good technique to grow GaInP for high band gap optical data storage applications and at lower growth temperatures. The optimum growth conditions in this study were at a growth temperature of 530°C on (001) GaAs substrate with 15° off-cut towards [111]A.
Crystallographic Mapping in Scanning and Transmission Electron Micrsocopy with Application to Semiconductor Materials
Authors: Dingley D. J. , Wright S. I. , Dingley D. J. 
Published: April 2011

AbstractThe two sister techniques, Electron Backscatter Diffraction and Orientation Imaging Microscopy which operate in a scanning electron microscope, are well established tools for the characterization of polycrystalline materials. Experiment has shown that the limiting resolution for mapping is the order of 0.1 microns. The basic techniques have been extended to include multiphase mapping. Whereas it has been possible to distinguish between phases of different crystal systems easily, it has not been possible to distinguish between phases that differ in lattice parameter by less than 5 %.An equivalent transmission electron microscope procedure has been developed. The technique couples standard hollow cone microscopy procedures with dark field microscopy. All possible dark field images that can be produced by tilting the electron beam are scanned to detect under what settings each crystal is brought into a diffracting
condition. Subsequent analysis permits determination of both crystal phase and orientation.
Grain Size Distribution and Degree of Texture in Films Used in Integrated Circuits
Authors: Lindsay R. , Chapman J. N. , Craven A. J. , Mcbain D. , Molchanov I. 
Published: April 2011

AbstractAs miniaturisation proceeds, the electrical properties of conductive films used in modem IC's are increasingly influenced by the grain sizes and the texture of the films. There is a need therefore to devise techniques which can examine these properties. Described in this work are two new cross-sectional TEM techniques for use on fully-processed IC's to determine quantitatively grain size distributions and the degree of texture in a film. The technique which investigates texture is used to determine how quickly the texture develops through a polysilicon film.
High Temperature X-Ray Diffraction in Transmission Under Controlled Environment
Authors: Margulies L. , Kramer M. J. , Williams J. J. , Deters E. M. , McCallum R. W. , Haeffner D. R. , Lang J. C. , Kycia S. , Goldman A. I. 
Published: April 2011

ABSTRACTA compact tube furnace has been developed for high temperature X-ray diffraction studies using high energy synchrotron radiation. The furnace design has a low absorption path in transmission yet allows for a high degree of control of the sample atmosphere and a minimal temperature gradient across the sample. The design allows for a maximum temperature of 1500°C with a variety of atmospheres including inert, reducing, and oxidizing. Preliminary results obtained at the SRI-CAT I-ID undulator line (60keV) at the APS facility and the A2 24 pole wiggler line (45keV) at CHESS on the Ti5Si3Z5 (Z = C, N, O) system will be presented to demonstrate the feasibility of this approach.
Applications of Synchrotron Infrared Microspectroscopy to the Study of Inorganic-Organic Interactions at the Bacterial- Mineral Interface
Authors: Holman Hoi-Ying N. , Perry Dale L. , Martin Michael C. , Mckinney Wayne R. 
Published: April 2011

ABSTRACTSynchrotron microspectroscopy has been used to study the inorganic-organic interactions in the mid-infrared region (4000#x2013;400 cm#x2212;1) as Arthrobacter oxydans attach themselves to magnetite surfaces. Relative band intensities and band intensity ratios for functional groups of organically-derived biological molecules that are inherent to the experimental system are discussed. The molecular components as they are perturbed by interactions with water, dichromate and chromate metal ions on the mineral surfaces are investigated. Mapping of the spectral markers for the inorganic-organic interactions at the biological- mineral interfaces is presented and discussed. Comparative analyses of the synchrotron infrared microspectra suggest that the bacterial-chromium interactions depend on the solubility and toxicity of the chromium compounds.
Angle-Resolved Photoemission Study of The Electronic Structures of Auai1 and Ptga2
Authors: Hsu L.-S. , Denlinger J. D. , Allen J. W. 
Published: April 2011

ABSTRACTIn this work, in-situ doped polysilicon and poly-SiGe films have been used as the gate material for the fabrication of MOS devices to evaluate their respective performances. These films were deposited in an RTCVD system using a Si2H6 and GeH4 gas mixture. MOS capacitors with 45 Å thick gate oxides and polysilicon/poly-SiGe gates were subjected to different anneals to study boron penetration. SIMS analysis and flat band voltage measurements showed much lower boron penetration for devices with poly-SiGe gates than for devices with polysilicon gates. In addition, C-V measurements showed no poly depletion effects for poly-SiGe gates while polysilicon gates had a depletion effect of about 8%. A comparison of resistivities of these films showed a low resistivity of 1 mΩ-cm for poly-SiGe films versus 3 mΩ-cm for polysilicon films after an anneal at 950 °C for 30 seconds.