bluuebunny/crossref_metadata_2025 huggingface dataset:
A Soft Solution Process to Synthesize Nanocrystalline Barium Zirconate via Reactive Solid State Precursors
Authors: Athawale Anjali A. , Bapat Malini
Published: March 2009

Barium zirconate, a perovskite oxide has been synthesized by a new procedure using solid state metathesis reaction precursors subjected to sonication. We report the lowest temperature of synthesis with particle size ranging from 20 to 30 nm. The initial stage involves formation of composite hydroxide nanoparticles by the solid state reaction of precursor salts with KOH at ambient temperature followed by sonication. BaZrO3 formation as a consequence of ultrasonicator output power variation and ultrasonic time variation has been studied. Results indicate that the process is convenient, low energy, environmentally benign and having narrow particle size distribution of BaZrO3.
Development of a Novel Micro-Spray-Assembly Process for Multilayer Ultra-Thin Film Formation
Authors: Peng Zheng , Kong Ling Xue
Published: March 2009

A novel micro-spray-assembly process and an automatic device to fabricate multilayer ultra-thin film are introduced. Employing self-assembly monolayer (SAM) technique, ultra-thin film can be assembled by utilizing the micro-spray-assembly device. The thickness and roughness of each monolayer can be controlled by varying various materials attributes, i.e., deposition time, ionic strength, pH value, molecular concentration and by selecting different manufacturing parameters of the automatic device such as spraying rate, size of micro-drop, N2 flow rate, temperature of N2 flow.
Synthesis, Fabrication, Characterization, Properties and Thermo-Oxidative Stability Study of Poly(ether imide)/MMT Clay Nanocomposites
Authors: Vora Rohitkumar H. , Jayaganthan Rengaswamy , Wang Zhida , Thin Ei Thin , Bang Toong Kiang
Published: March 2009

A series of partially fluorinated poly(ether imide) (6F-PEI) and (6F-PEI)/Organosoluble MMT clay nanocomposite were synthesized. XRD data, indirectly confirmed the exfoliation of diamine modified MMT clay at molecular level in the nanocomposite. Thermal properties, and longterm thermo-oxidative stability, thermal degradation kinetics, moisture absorption, chemical resistance of (6F-PEI)s, and nanocomposite films were studied and reported in this paper.
The Growth of Carbon Nanostructure on the Mechanical-Milling-Derived Catalyst Precursors
Authors: Liu B.H. , Ding J. , Dong Z.L. , Zhong Zeng Yong , Lin Jian Yi , White T.J.
Published: March 2009

Mechanical milling was employed to prepare the nanocomposite precursors for the catalytic growth of carbon nanostructures. For alumina substrates, our study showed that mechanical-millingderived catalyst precursors possessed high hydrogen reduction efficiency that in turn enabled the high yield of CNTs. The alloying effects presented by the mechanical milling could accelerate the
substitutional reactions between the parent oxides and thus the quality of CNTs was apparently improved. In addition, by using water-soluble substrates such as NaCl, we realized large-scale formation of carbon-encapsulated metal nanoparticles (CEMNs) that can be completely separated by a simple washing process. It was found that the morphologies of as-obtained carbon nanostructures were strongly dependent on the substrate effects. By selecting different salt substrates, we can strategically change the morphologies of the as-obtained nanostructures, from CNTs to CEMNs and the intermediate state between CNTs and CEMNs, such as quasi-nanocages.
Vapor Phase Growth of Carbon Microcoils / Nanocoils
Authors: Yang S. , Chen X. , Motojima S.
Published: March 2009

The carbon microcoils and carbon nanocoils were prepared by the catalytic pyrolysis of acetylene under the Ni and/or Fe-containing catalysts, and the growth pattern, morphology and growth mechanism of the carbon coils were examined in detail. The inner coil diameter of carbon microcoils are of several µm and coil gap from zero to several µm. The inner coil diameter of carbon nanocoils are from zero to several ten nm and coil gap from zero to several nm. The carbon microcoils are
generally of double helix coils such as DNA while carbon nanocoils were single helix coils such as α-helix proteins, with spring-like or twisted forms. A catalyst grain was usually observed on the tip of carbon coil. The carbon nanocoils are almost amorphous and can be graphitized by the high temperature heat-treatment.
Large Stress Reduction Induced by sp2 Clustering in Tetrahedral Amorphous Carbon Films
Authors: Zhang Yue Bin , Lau S.P. , Prawer S. , Tay B.K.
Published: March 2009

The intrinsic stress of tetrahedral amorphous carbon film as a function of annealing
temperature is investigated. The film was deposited using the filtered cathodic vacuum arc technique and subsequently annealed at various temperatures. The stress is determined by Stoney’s equation using surface profilometry, and the microstructure is studied using atomic force microscopy, visible and ultraviolet Raman spectroscopy. It is found that as the annealing temperature increases the film stress decreases slowly up to 500 oC and then falls quickly at 600 oC.
It is interesting to note that at this temperature sp3 fraction retains while sp2 clustering begins, which contributes to the sharp decrease in the stress.
Laser Induced Etching for Generation of Si Nanocrystals and Spectroscopic Investigation of Morphology
Authors: Mavi H.S. , Rath S. , Shukla Arun
Published: March 2009

Laser-induced etching of silicon is used to generate silicon nanocrystals. The pore structure depends on the substrate type and etching laser wavelength. Porous silicon (PS) samples prepared by Nd:YAG laser (1.16 eV) etching of n-type substrate showed a fairly uniform and highly interconnected network of nearly circular pores separated by thin columnar boundaries, while no circular pits were
produced by argon- ion laser (2.41 eV) etching under similar conditions. The size and size distribution of the nanocrystals are investigated by Raman and photoluminescence spectroscopies and analyzed within the framework of quantum confinement models.
On the Wettability of Nanocomposite Amorphous Carbon Films
Authors: Zhang P. , Tay B.K. , Yu G.Q. , Lau S.P.
Published: March 2009

Nanocomposite Si containing amorphous carbon (a-C:Si) and metal containing amorphous carbon (a-C:Me) films including a-C:Al, a-C:Ti, and a-C:Ni were prepared by the filtered cathodic vacuum arc (FCVA) technique The metal-carbon (5 at.% metal) composite targets were used. The VCA Optima system was used to measure the contact angle. Three types of liquid were used to study the changes in the surface energy. X-ray photoelectron spectroscopy (XPS) was employed to analyze the composition and chemical state of the films. The surface morphology and roughness of the films were determined by atomic force microscopy (AFM). The Al containing films show the highest contact angle with water, which reaches as high as 101.26°. The Si containing films show the lowest contact angle around 64°. The contact angles of Ni, and Ti containing films are around 83°, 96.5°, respectively. The absorption of oxygen on the surface play an important role on the polar component of the a-C:Me films. The formation of Al-O, and Ti-O bonds is responsible for the lower polar component. The metal state Ni results in higher polar component. The Si-O bond contributes to the high polar component of a-C:Si film. As all films are atomic scale smooth, the RMS roughness is below 0.5 nm, the roughness does not have obvious effect on the surface energy.
Anodization of Nanoporous Carbons for Removal of Ammonia
Authors: Park Soo Jin , Shin Jun-Sik
Published: March 2009

In this study, a new nanoporous carbon was prepared by anodic oxidation treatment to remove noxic ammonia gas. The acid- and base values of the nanoporous carbon were determined by Boehm’s titration method. And, the surface properties of the carbons were investigated by XPS analysis. Also, N2/77K adsorption isotherm characteristics, including the specific surface areas and
nano/micropore volumes were studied by BET and t-plot methods, respectively. The ammonia removal efficiency was confirmed by gas-detecting tube technique. As a result, it was revealed in the case of acidic treatment on nanoporous carbons that the ammonia removal was greatly effective due to the increase of OH groups in carbon surfaces without significant changes of nanostructural properties. It
was then found that the acidic anodization of nanoporous carbons was a suitable method for the effective removal of ammonia gas, which could be attributed to the increase of acceptor-donor interactions between acidic oxygen functional groups of carbon adsorbent and basic adsorbate in an adsorbent-adsorbate system.
Li Storage Properties of Ag and SnO 2 Nanopowders Synthesized from Reverse Micelles
Authors: Ahn Jung Ho , Kim Yong Jin , Wang G.X. , Liu H.K.
Published: March 2009

Ag and SnO2 nanopowders were synthesized by reverse-micelle method. The reverse micelles were prepared to form tiny aqueous droplets dispersed in oil-based solvents. Two reverse micelles containing metallic salts and reductive agents were rigorously mixed to form nanoparticles inside aqueous droplets by a reductive reaction. The spherical powders of 20~50 nm were formed during the process. The resulting Ag and SnO2 nanopowders were examined as the anode electrode for lithium-ion cells. The reversible discharge capacity of the Ag and SnO2 nanopowders after 25 cycles were 315 and 380 mAh/g, respectively.
Blood Platelet’s Behavior on Nanostructured Superhydrophobic Surface
Authors: Zhou Ming , Yang Jia Hong , Ye Xia , Zheng Ao Ran , Li Gang , Yang Pei Fang , Zhu Yi , Cai Lan
Published: March 2009

Regular arrays of micro-pillars and nano-grooves structures on the silicon wafer are
fabricated by using soft lithography, and the three dimension morphology of textured surface is
observed by using scanning electron microscopy (SEM) and atomic force microscope (AFM). The
static water contact angles are measured by using contact angle meter to characterize the
wettabilities of these surfaces. To investigate how the presence of topography and the variations of
wettability affect the haemocompatibility of textured surface contacted with blood, different
patterned surfaces are designed and fabricated, and blood platelet adhesion test is carried out on
these surfaces. The adhesion and coagulation of platelets are inspected by scanning electron
microscopy (SEM). Experimental data presented in this paper indicate that different surface
roughness and wettability are the important factors for blood platelet adhesion. The amount of
adsorbed blood platelet is low on textured surfaces, compared with that on the flat surface.
Especially, there is no coagulation and activation on the surface with nanometer grooves. That is to
say, the superhydrophobic surface is apt to decrease blood platelet adhesion. The study suggests that
surface with suitable wettabililty and textured structures exhibits superior blood compatibility.
Controlled Deposition and Electrical Characterization of Multi-Wall Carbon Nanotubes
Authors: Moshkalev S.A. , Leon J. , Veríssimo Carla , Vaz A.R. , Flacker A. , de Moraes M.B. , Swart J.W.
Published: March 2009

A method of ac dielectrophoresis was applied to align and deposit metallic multi-wall
carbon nanotubes between pre-fabricated metal (Au, Pd) electrodes with a micron scale separation.
For improvement of nanotube contacts with electrodes, Ni and Pd electroless processes were
developed, and significant reduction of 2 terminals resistances was demonstrated. Further, using
electron and ion beam deposited Pt contacts in two different configurations (“Pt-on-CNT” and
“CNT-on-Pt”), 4 terminals measurements have been performed to evaluate intrinsic nanotube
resistances. The values between 90 and 130 kΩ/μm were obtained, while systematically lower
values (30-70 kΩ/μm) were estimated using 2 terminals method. The 4 terminals method was
applied to study the effect of ion irradiation on the electrical parameters of supported nanotubes.
INVITED PAPER: Instrumentation and Biological Applications of High-Resolution Frequency Modulation Atomic Force Microscopy in Liquid
Authors: Fukuma Takeshi
Published: March 2009

Frequency modulation atomic force microscopy (FM-AFM) has been a powerful tool for imaging atomic-scale structures and properties of various materials including metals, semiconductors, metal oxides, alkali halides and organic systems. Whilst the method has been used mainly in ultrahigh vacuum environments, recent progress in FM-AFM instrumentation made it possible to apply this technique also to investigations in liquid. This technological innovation opened up a variety of applications of FM-AFM in biology and electrochemistry. To date, the improved FM-AFM instrument and technique have been applied to investigations of several biological materials, providing novel information that has not been accessible with other imaging techniques. In this review, I will summarize the recent progress in FM-AFM instrumentation and biological applications in liquid.
Annealing Effects on RF Sputter Deposited a-Si/a-C Multilayers
Authors: Ech-chamikh E. , Essafti A. , Azizan M. , Debbagh F. , Ijdiyaou Y.
Published: March 2009

Amorphous silicon on amorphous carbon (a-Si/a-C) multilayers was deposited by RadioFrequency (RF) sputtering. These multilayers were obtained by alternate deposition of a-C and a-Si layers, respectively from graphite and silicon targets of high purity, on crystalline silicon substrates. The RF power and the argon pressure, during the pulverization, were maintained respectively at 250W and 10-2 mbar. The annealing effects, at temperatures of 450°C and 750°C, on the deposited structures were investigated by X-ray reflectometry. The a-Si/a-C interfaces are abrupt before and after annealing at 450°C. The annealing at 750°C leads to a net decrease of both the upper a-Si layer thickness and the total multilayer thickness with a net enhancement of the interfaces reactivity. The upper silicon layer is crystallized after annealing at 750°C.
Mobility of DR1 Molecules Embedded in Nanostructured PMMA Films
Authors: García-Macedo Jorge A. , Franco A. , Valverde-Aguilar Guadalupe , Ríos-Enríquez M.A.
Published: March 2009

The kinetics of the orientation of Disperse Red 1 (DR1) molecules embedded in nanostructured Polymethylmetacrylate (PMMA) films was studied under the effect of an intense constant electric poling field. The changes in the orientation distribution of the DR1 molecules were followed by Second Harmonic Generation (SHG) measurements. The SHG signal was recorded as function of time at three different temperatures. We focused on both, the signal increases under the presence of the poling field and the signal decays without the poling field. The studied PMMA films were nanostructured by the incorporation of ionic surfactants as the Sodium Dodecyl Sulfate (SDS) and the Cetyl Trimethyl Ammonium Bromide (CTAB) during their preparation. The kinds of nanostructures obtained in the films were determined by means of X-ray diffraction (XRD) measurements. Substantial differences in signal intensity and in growth and decay rates between amorphous and nanostructured films were found.
Electronic and Vibrational Properties of Porous Silicon
Authors: Cruz-Irisson Miguel , Wang Chu Min
Published: March 2009

For ordered porous silicon, the Born potential and phonon Green’s functions are used to investigate its Raman response, while the electronic band structure and dielectric function are studied by means of a sp3s* tight-binding supercell model, in which periodical pores are produced by removing columns of atoms along [001] direction from a crystalline Si structure and the pores surfaces are passivated by hydrogen atoms for the electronic band structure calculations. This supercell model emphasizes the interconnection between silicon nanocrystals, delocalizing the electronic and phononic states. However, the results of both elementary excitations show a clear quantum confinement signature, which is contrasted with that of nanowire systems. In addition, ab-initio calculations of small supercells are performed in order to verify the tight-binding results. The calculated dielectric function is compared with experimental data. Finally, a shift of the highest-frequency Raman peak towards lower energy is observed, in agreement with the experimental data.
Cathodoluminescence Quenching in Yb-Doped ZnO Nanostructures
Authors: Susarrey-Arce A. , Herrera-Zaldívar M. , de la Cruz W. , Pal Umapada
Published: March 2009

Cathodoluminescence (CL) quenching was observed in ZnO nanostructures when doped with Yb by both chemical and physical methods. CL spectra of the samples revealed a defect emission at 2.25 eV in samples prepared by the chemical method, and an emission at 2.5 eV in samples prepared by the physical method. From the thermal treatment studies, it was found that oxygen vacancies are responsible for the 2.5 eV emission. Observed CL quenching in ZnO is explained through the participation of point defects in the energy transfer process from ZnO to Yb3+.
Field Emission Properties of Al-Doped ZnO Nanostructures
Authors: Navale Shalaka C. , Sheini Farid Jamali , Patil Sandip S. , Mulla Imtiaz S. , Joag Dilip S. , More Mahendra A. , Gosavi Suresh W.
Published: March 2009

Field emission from Al-doped ZnO nanostrcutures has been investigated in planar diode configuration under ultra high vacuum conditions. The Al-doped ZnO nanostructures were synthesized by co-precipitation method with varying aluminium concentrations. The as- synthesized product was characterized by x-ray diffraction, scanning electron microscope and energy dispersive x-ray analysis. The threshold field required to draw a current density of ~ 1 μA/cm2 was observed to be ~ 2.0 V/μm and ~ 2.3 V/μm for Al-doped ZnO nanostructures synthesized with aluminium concentrations of 1% and 3%, respectively. The Fowler- Nordheim (F-N) plots for both the specimens exhibit non-linear behaviour, which is observed to be specimen dependent. The non-linearity observed in the F-N plots has been interpreted on the basis of the theory of electron emission from semiconductor emitters. The field enhancement factors, estimated from the slope of the F-N plots, are found to be ~ 9.3 x 103 and 3.9 x 103 for 1% and 3% Al-doped ZnO emitters, respectively. The high values of the field enhancement factor suggest that the emission is from the nanostructures. The emission current stability measured at the preset value of ~ 2 μA over a period of more than three hours is found to be fairly stable. The results indicate use of Al-doped ZnO nanostructures as promising emitters for field emission based devices.
Fourier Electron Density Maps for Nanostructured TiO2 and TiO2-CeO2 Sol-Gel Solid
Authors: Galindo-Hernández Félix , Gómez Ricardo
Published: March 2009

Sol-gel TiO2 and TiO2–CeO2 materials were synthesized at pH3 using HNO3 as hydrolysis catalysts. Gels were annealed at 473, 673 and 873 K for 4h. X-ray diffraction Rietveld refinement was used to determine the mean crystallite size, TiO2 stoichiometry (titanium deficiency) and Fourier electronic density maps. It has been found that the fractal surface dimension diminishes on TiO2 a
nd TiO2–CeO2 surfaces as the annealing temperature increases. The X-ray diffraction patterns showed nanocrystalline anatase phase in the range of 8.9 to 43.6 nm in depending of the annealing temperature. A dependency between the crystallite size and the titanium deficiency [V+Ti4+] per unit cell was found, as lowest is the crystallite highest is the titanium deficiency. Strong differences on the Fourier electron density map were found on TiO2 and TiO2–CeO2 materials. It was concluded that the sol-gel preparation method favors the formation of nanosized TiO2 with high Ti4+ stoichiometry deficiency.
Bulk Fe-Al-C Nanoalloys Made by Mechanically Alloying with Subsequent Spark Plasma Sintering and Their Mechanical Properties
Authors: Minamino Yoritoshi , Koizumi Yuichiro , Tsuji Nobuhiro , Hirohata Naoko , Mizuuchi Kiyoshi , Ohkanda Yoshihira
Published: March 2009

Three kinds of bulk nanocrystalline Fe-24at%Al-Xat%C (X=1,2,4) alloy were produced from Fe and Al powders with addition of methanol by MA with subsequent SPS at 1273K under 64MPa. Their microstructure and mechanical properties were investigated. The compacts have the relative densities of 99.97% (1at%C) to 99.6% (4at%C). The structure of compacts with 1at%C is composed of Fe3Al grains of 1.5µm in diameter and nano k-carbides (Fe3AlC0.5) precipitates, while those of compacts with 2 and 4at%C are composed of nanocrystalline Fe3Al of about 80nm in diameter, nano k-carbides and a-grains of about 1µm in diameter. These structures have the good thermal stability, maintaining the nanostructure even at 973K. The mechanical properties of these compacts were measured by compression tests at R.T. to 973K. The compacts with 1at%C and 2at%C of this work perform the superior mechanical properties (e.g. yield strength of 2.15GPa and rupture strain of 0.14 for compact with 2at%C at R.T.) when compared with the ordinary Fe3Al casting (e.g. 380MPa and 0.12). They also exhibit no environmental embrittlement, which is one of fatal problems for the ordinary Fe3Al mateials.
Mechanical Properties of Aluminium Wires Produced by Plastic Consolidation of Fine Grained Powders
Authors: Dybiec Henryk , Kozak Paweł
Published: March 2009

The paper presents results of mechanical tests and grain structure investigation of
aluminium wires obtained by plastic consolidation of aluminium powders produced by atomisation from liquid state. The powders produced by this method could be potentially adopted to obtain ultra fine/nano structured materials by rapid solidification. Conversion of material from powder to bulk state with retaining of powders fine structure and minimizing of porosity are crucial for technological route of sub-micron grained materials production. An influence of condition of plastic
consolidation by hot extrusion on mechanical properties of consolidated products is a main target of presented investigation. The standard mechanical properties of extrusion products have been determined and grain structure has been inspected. The results have been compared to extrusion products of conventional bulk aluminium. It has been stated substantial increase of properties and refining of grain structure in materials consolidated from powders.
Phase Transformations in Carbon Steel Powders Subjected to Ball Milling
Authors: Oleszak Dariusz , Janczewski A. , Grabias Agnieszka
Published: March 2009

The tool carbon steel powder, containing 1.1 % C, was subjected to heavy cold working by ball milling in a Fritsch P5 planetary ball mill. XRD studies showed that ball milling results in a dissolution of cementite and formation of nanoferrite. The crystallite size and lattice strain of ferrite, calculated by applying Williamson-Hall method, were 10 nm and 1%, respectively. Mössbauer spectroscopy measurements confirmed the formation of a phase called “distorted ferrite”,
characterized by the values of hyperfine field of 28.5 T and isomer shift of 0.15 mm/s, different from ones of ferrite (32.9 T and 0.00 mm/s, respectively). DSC investigations revealed two heat effects recorded during heating the sample after 100 h of ball milling: exothermic effect at 360oC and endothermic one at 580oC. The first one was attributed to the dramatic decreasing of lattice strain (from 1% after milling down to 0.1%, as showed XRD studies) and slightly increasing of crystallite size (from 10 to 25 nm).The formation of Fe3C was not observed in this temperature and the structure of nanoferrite was preserved. The second observed heat effect was reversible and probably related to the eutectoid transformation, shifted by ball milling to lower temperature range, comparing to equilibrium conditions.
Prevention of Copper Cross-Contamination on Cu Process and Non-Cu Process Mixed Fabrication
Authors: Shim Joon Bum , Lee Kang Hyun , Kim Kee Ho , Park Heung Soo
Published: March 2009

When the integration of Cu process and non-Cu process is mixed in the fabrication, the prevention of Cu cross-contamination between wafer-to-wafer and machine-to-machine is critical. This study suggests a prevention method of the cross-contamination in Cu fabrication line.
Adhesion and Removal of Alumina Slurry Particles on Wafer Surfaces in Cu CMP
Authors: Hong Yi Koan , Han Ja Hyung , Lee Jin Hyung , Park Jin Goo , Busnaina Ahmed A.
Published: March 2009

The adhesion force and removal of alumina particles on Cu, Ta, TEOS, SILKTM, Aurora and FSG wafer surfaces were experimentally and theoretically investigated in slurry solutions of different pHs. These wafer surfaces showed negative zeta potentials in the investigated pH ranges with exception of FSG and Ta. However, the zeta potentials of FSG surface drastically decreased with increasing pH. The lowest adhesion force and smallest number of alumina particles were measured between alumina particle and FSG surface in a slurry solution of pH 11. Alkaline slurry was much more desirable in controlling the level of particle contamination during Cu CMP. The pH of the slurry and zeta potentials of the surfaces played important roles in controlling the interaction force.
Effect of Chemical Solution on the Stability of Low-k Films
Authors: Kesters Els , Le Quoc Toan , Baklanov Mikhail R. , Boullart Werner , Mertens Paul W.
Published: March 2009

The compatibility of chemical solutions with different pH is studied on microporous silica-based (SiOCH) and mesoporous methylsilsesquioxane (MSQ) based low-k materials. The surface and bulk properties of as-deposited and O2/CF4 plasma-treated low-k films have been studied after several wet treatments.
Aqueous Based Single Wafer Cu/Low-k Cleaning Process Characterization and Integration into Dual Damascene Process Flow
Authors: Tang Jian She , Brown Brian J. , Verhaverbeke Steven , Chen Han Wen , Papanu Jim , Hung Raymond , Cai Cathy , Yost Dennis
Published: March 2009

As device features scale down to 90nm and Cu/low-k films are employed for back end interconnects, post etch and ash residue cleaning becomes increasingly challenging due to the higher aspect ratio of the features, tighter CD control requirements, sensitivity of the low-k films, and the requirement for high wet etch selectivity between CuxO and Cu. Traditional solvent based cleaning in wet benches has additional issues such as wafer cross-contamination and high disposal
cost [1, 2]. We have developed a novel aqueous solution (AQ) based single wafer cleaning process to address these challenges. The results of physical characterization, process integration electrical data, and process integration reliability data such as electromigration (EM) and stress migration data are presented. The main conclusions can be summarized as follows: (1) The single wafer cleaning process developed on the Oasis™ system can clean post etch residues and simultaneously clean the wafer front side and backside metallic contaminants; (2) In terms CuxO and Cu wet etch selectivity, CD loss control, the Oasis™ aqueous single wafer clean process is superior to the bench solvent cleaning process; (3)The Oasis aqueous cleaning process shows no undercut below etchstop due to the very low Cu etch amount in one cleaning pass, therefore the electromigration and stress migration performance of the aqueous Oasis processed wafers is clearly better than that of the solvent bench processed wafers.
Advanced Aqueous Cleaner II: PER Removal from Sensitive Cu/Low-k Devices
Authors: Reid Chris , Daviot Jerome , Holmes Douglas
Published: March 2009

This paper described the development of two types of Advanced Aqueous Cleaners (AAC™) for Aluminium (Al) Post Etch Residue (PER) removal. The first approach was developed to address a need for cleaning chemistries with a smaller environmental footprint that were also able to clean at significantly lower process times and temperatures than conventional wet chemical cleans. A broad screening experiment was undertaken during which it was highlighted it was possible to clean Al lines in an acidic region though this technology was not extendable to cleaning via features. However, the study emphasised the need to use a selective alkaline reducing formulation to maintain a high cleaning efficiency for the more complex residues formed during via etch. The novel Back End Of Line (BEOL) PER cleaners presented in this paper were optimised using a statistical Design Of Experiment (DOE) to perform at lower temperatures and shorter process times and were Fluoride and organic solvent free while containing a minimum of 80%wt water.
New Post Etch Polymer Removal Process for Al-Interconnects and Vias in Tank and Spray Tools Using a New Inorganic Chemistry
Authors: Mellies Raimund , Kunz Stefan , Nilius Franz , Mayer Dieter , Kühner Andreas
Published: March 2009

A Post-Etch-Residue (PER) removal process for tank and spray tools has been developed using a new inorganic aqueous based chemistry. The performance of this new type of polymer remover, Inosolv 400 Fotopur®, on process wafers is compared with other inorganic chemistries such as DSP (Dilute Sulphuric acid hydrogen Peroxide) and DSP+, containing traces of HF. Inosolv 400 Fotopur®
has improved polymer removal capabilities. Furthermore Inosolv 400 Fotopur® does not show any attack of the metal or dielectric layers and is inorganic based and thus
environmentally friendly.
Determination of Grain-Orientation-Dependent Stress in Coatings
Authors: Wang Yan Dong , Peng Ru Lin , Almer Jonathan , Odén Magnus , Liu Y.D. , Zuo Liang
Published: March 2009

Quantitative interpretations of the so-called non-linear lattice strain distributions observed in coatings and thin films are important not only for determining the macro- and microstress fields, but also for inferring the active mechanisms of grain interactions during various deposition processes. In this paper, we present a method, which determines simultaneously both the macro- and micro- stress fields in the coatings and thin films. This method is extended from the previous stress-orientation distribution function (SODF) analysis method, which has already been used for residual stress analysis in bulk materials subjected to rolling and fatigue deformation. The validity of analysis method is demonstrated through measurements of lattice strains by high-energy x-ray and analysis of grain-orientation-dependent stresses in a CrN coating.
Electric Field Annealing on 3104 Aluminum Alloy Sheets: Evolution of Microstructure and Texture
Authors: Hu Zhuo Chao , Zhang Yu Dong , Zhao X. , Zuo Liang , Esling Claude
Published: March 2009

The cold-rolled 3104 aluminum alloy sheets were annealed without and with an electric field. Results show that the electric field can greatly postpone the recovery and recrystallization processes, enhance the Cube texture component. The effect of the electric field lies in that it decreases the concentration of the electronegative vacancies by attracting them to the electropositive sample surface, thus reducing the stored energy for recovery and recrystallization.
Regular Substructure Inhomogeneity of Textured Materials by the Example of Rolled Ti-Ni Single Crystals
Authors: Perlovich Yuriy , Isaenkova Margarita , Fesenko Vladimir , Bunge Hans Joachim
Published: March 2009

The substructure inhomogeneity of rolled Ti-48%Ni-2%Fe single crystals was studied by the X-ray method of Generalized Pole Figures. Under rolling of single crystals, along with texture formation, the nonuniform substructure develops. It is conditioned by inhomogeneous reorientation of the crystalline lattice and local differences in predominant plastic deformation mechanisms. The distribution of residual deformation effects is controlled by the orientation of separate regions relative to texture maxima. Rolled single crystals prove to be divided into subcomponents with close orientations and opposite signs of elastic microstrains.
Cross-Sectional Texture Gradients in Interstitial Free Steels Processed by Accumulated Roll Bonding
Authors: Reis Ana Carmen C. , Kestens Leo
Published: March 2009

An interstitial-free steel was severely plastically deformed in an accumulative roll bonding (ARB) experiment with 10 consecutive passes applied at 480°C. Nominal reductions of 50% per pass and an intermediate annealing treatment of 5 min. at 520°C were employed. A total true strain of evM = 8.00 was applied, which corresponds to an accumulated reduction of 99.9%. The evolution of texture and microstructure was monitored by means of orientation imaging microscopy. A lamellar microstructure, characteristic of severely rolled sheet materials, was observed even after the highest strains. The average lamellar width was determined as a function of rolling strain. Under the experimental limitations in terms of spatial resolution, no significant difference was observed between the average lamellar width in the mid-section and near the surface of the sheet. Texture analysis revealed a conventional cross-sectional gradient with plane strain rolling components in the mid-layers and shear components in the subsurface regions. Although these different strain modes did not affect the microstructure in terms of the average lamellar spacing, an effect was observed on the average aspect ratio of the grains. This was much higher in the sheared (surface) layers than in the plane strain compressed (centre) areas. The surface structure did not have an effect, though, on the bulk microstructural evolution in spite of the specific nature of the ARB process during which the surface layer of one pass reappears in the mid-section of the next pass.
A New Perspective on the Mathematical Modeling of Highly Nonlinear Anisotropic Plastic Flows in a Heterogeneous Solid
Authors: Tong Wei
Published: March 2009

A new mathematical formulation is presented for describing the three-dimensional anisotropic plastic flow behavior of a heterogeneous polycrystalline solid. By using three principal stresses, three loading orientation angles, and a generally non-quadratic, real-valued stress exponent, a mathematical theory of anisotropic plasticity is formulated as two coupled orthogonal series expansions in both the 3D principal stress space (the p–plane) and the 3D loading orientation space. A geometrical interpretation of the new mathematical representation of anisotropic plasticity is offered. Specific examples are given to illustrate the application of the proposed theory for modeling the plastic anisotropy of orthotropic polycrystalline sheets under uniaxial and biaxial tension.
Combined Analysis of Bi2223 Superconducting Bulk Materials
Authors: Guilmeau E. , Chateigner Daniel , Noudem J. , Ouladdiaf B.
Published: March 2009

Orientation distributions of polyphased (Bi,Pb)2Sr2Ca2Cu3O10+d superconducting textured materials are determined from neutron diffraction analysis. The quantitative texture analysis of neutron data was accomplished by using the combined Rietveld-WIMV-Popa algorithms, implemented in the program package Materials Analysis Using Diffraction (MAUD). Curved position-sensitive detector and 4-circle diffractometry allow the whole diffraction pattern treatment. Transport critical current densities, measured on different samples, are strongly dependent of the calculated texture strengths, crystallite sizes and phase ratios. The results prove the interest of the combined approach for a quantitative texture analysis of complex materials. Texture to anisotropic physical properties relationship is discussed.
Texture Measurements of Hydroxyapatite Crystallites at Bone-Implant Interfaces in Sheep Tibia
Authors: Benmarouane A. , Hansen T. , Millet Pierre , Lodini Alain
Published: March 2009

The preferred orientation of hydroxyapatite Ca10(PO4)6(OH)2 (HAp) crystallites at the interface bone-implant in sheep tibia bones has been measured with the neutron 2-axis diffractometer D20 at the Institut Max von Laue-Paul Langevin, extracted 60 days after implantation. The implant has two faces, one coated and one non-coated with plasma-sprayed HAp (80 µm). We probed the samples with a spatial resolution of 0.5 mm started from the interface in order to inspect the reorganisation of the HAp crystallite distribution after implantation.
Textured YBaCuO Films Enhanced by Cold Rolling and Melt Growth Process in Low Oxygen Partial Pressure
Authors: Wang J. , Maloufi N. , Xue Xiang Xin , Fan Z.G. , Esling Claude
Published: March 2009

High critical current density Jc under high magnetic field is required in numerous applications for high temperature superconductor YBa2Cu3O7-δ (Y123). Significant efforts have been made to control sample preparation in view of optimized textures and microstructures. In YBa2Cu3O7-δ superconductor, Jc is limited by grain misalignment and by other defaults like secondary phase (Y211), microcracks... So YBaCuO films were prepared by electrophoretic deposition directly on polycrystalline Ag substrate. Melt textured growth (MTG) in low oxygen partial pressure and cold rolling were performed to YBaCuO samples respectively to improve texture growth of the films and to study deformation effect on the texture. The film obtained by melted growth after rolling has better texture orientation than the film without rolling, and presents higher critical current density.
Formation of Thallium Sulphide Layers on Polyethylene (PE) Sulphurised in a Solution of Higher Polythionic Acid
Authors: Bružaitė I. , Janickis V. , Ancutienė I. , Snitka Valentinas
Published: March 2009

Thallium sulphide layers of different composition were obtained on the surface of polyethylene when it was sulphurised in a solution of higher polythionic acid, H2S33O6, and then treated with an alkaline solution of thallium(I) sulphate. The stoichiometric composition of the thallium sulphide layers varied between Tl0.3S and Tl2.6S depending on the formation conditions of the layers of TlxSy. A phase composition of the layers obtained was confirmed by X-ray photoelectron spectroscopy. The spectra of Tl 4f7/2, O 1s and S 2p showed the bond of thallium
with sulphur in TlS and Tl2S , but Tl2SO4, Tl(OH)3, S8 and Tl2O3 were also found on the surface of the layers. Five thallium sulphide phases TlS, Tl2S, Tl2S2, Tl4S3 and Tl2S5 have also been identified in the layers by X-ray diffraction. The peaks of the TlS phase predominate in the diffractograms.
Polymer Matrix Composites with Particles of TiC Obtained by a Sol-Gel Method
Authors: Konopka K. , Biedunkiewicz Anna , Boczkowska Anna , Rosłaniec Zbigniew. , Kurzydlowski Krzysztof Jan
Published: March 2009

Nanoparticles of carbides, nitrides and carbonitrides can be used to reinforce polymer matrix nanocomposites to obtain the required strength, hardness, corrosion and wear resistance. In order to efficiently achieve the desirable properties the polymer matrix and nanoparticles must be optimised. This paper reports on studies undertaken on TiC reinforced polymer matrix nanocomposites. The TiC nanoparticles were produced by sol-gel method and nanocomposites were obtained in situ, via the reaction and synthesizing of polyether-ester copolymer (PEE). TiC nanoparticles were characterised with a scanning electron microscopy (SEM) and the microstructure of the composites was examined by SEM and atomic force microscopy (AFM). Tensile properties were determined. For comparison, samples of polymer were also studied and composites with submicron size of TiC particles. The results, which are discussed in terms of size of the TiC particles, showed that the particles incorporated in the polymer matrix, influence the strength of the composites.
Effect of Sintering Temperature on Structure and Properties of Al2O3/Ni-P Composites with Interpenetrating Phases
Authors: Michalski J. , Woźniak M.J. , Konopka K. , Bieliński J. , Gierlotka Stanislaw , Kurzydlowski Krzysztof Jan
Published: March 2009

An Al2O3/Ni-P composite was formed by hot pressing of alumina powder, coated with chemically plated nano Ni-P. The powders were consolidated at room temperature, 600 and 1000oC. The consolidated specimens were studied by SEM, TEM/HRTM, MFM (magnetic force microscopy) and tested or hardness. It was found that the fabrication method results in a structure of interpenetrating phases of high electric conductivity and that samples consolidated at room temperature and sintered at 600oC retain the nanometric grain size of the metallic phase. Hardness measurements are discussed in terms of the fabrication temperature and structure of the composites.
Laser-Induced Size and Shape Transformation of Silver Colloidal Nanoparticles
Authors: Tarasenko Nikolai , Butsen Andrei , Shevchenko Gvidona , Yakutik Ilona
Published: March 2009

In this paper studies of the changes of the morphology of silver colloidal nanoparticles under laser irradiation at different fluences and wavelengths have been presented. Silver nanoparticles of size 10-30 nm were prepared in a gelatin stabilized AgNO3 solution under reduction with K-Na-tartrate. They were then exposed to pulsed laser radiation at 532 nm, 400 nm and 266 nm. In addition to the fragmented particles, relatively larger-size (1400-1500 nm) rightangled structures were found to be formed in the solution. The experimental conditions favouring laser-induced transformation of the morphology of nanoparticles have been determined.
Direct Electrochemical Activity and Stability of Capped Platinum Nanoparticles
Authors: Cavaliere Sara , Raynal Frédéric , Etcheberry Arnaud , Herlem Michel , Perez Henri
Published: March 2009

4-mercaptoaniline functionalised platinum particles of 2 nm diameter were synthesised and over-grafted with 2-thiophenecarbonyl chloride. The derivative particles were dispersed in DMSO and gave long term stable suspensions. The Langmuir-Blodgett technique was then used to build up stable Langmuir-Blodgett films and the electrochemical behaviour of these ultra-thin films towards oxygen reduction was investigated in an acidic medium. It revealed direct activity without any previous activation treatments despite of the presence of the organic shell at the particle surface. Furthermore, XPS experiments revealed that the organic crown was not significantly destroyed on prolonged cycling. The results open a way to study original and versatile platinum-based nanocomposites.
Microstructural Characterization of BaTiO3 Ceramic Nanoparticles Synthesized by the Hydrothermal Technique
Authors: Zhu Xin Hua , Zhu Jian Min , Zhou Shun Hua , Liu Zhi Guo , Ming Nai Ben , Hesse Dietrich
Published: March 2009

BaTiO3 (BT) nanoparticles were prepared by the hydrothermal technique using different starting materials and the microstructure examined by XRD, SEM, TEM and HRTEM. X-ray diffraction and electron diffraction patterns showed that the nanoparticles were the cubic BaTiO3 phase. The BT nanoparticles prepared from the starting materials of as-prepared titanium hydroxide and barium hydroxide have spherical grain morphology, an average size of 65 nm and a fairly narrow size distribution. A uniform diffraction contrast across each single grain is observed in the TEM images, and the clear lattice fringes (with d110 = 0.28 nm) observed in HRTEM images reveal that well-crystallized BT nanoparticles are synthesized by the hydrothermal method. The edges of the particles are very smooth, with no surface steps. BT nanoparticles with average grain size of 90 nm, synthesized using barium hydroxide and titanium dioxide as the starting materials, show surface facets. In this case a bimodal size distribution of large faceted and smaller particles is observed. Diffraction contrast variation across the particles caused by high strains within the particles is clearly observed. The high strains obviously stem from structural defects formed during hydrothermal synthesis, presumable in the form of lattice OH− ions and their compensation by cation vacancies. HRTEM images demonstrate that surface facets parallel to the (100) and (110) planes and small islands with 3 ~ 4 atomic layer thickness are frequently observed around the edge of the particles.
Phase Stability in Nanocrystalline Zirconia
Authors: Baldinozzi Gianguido , Simeone David , Gosset Dominique , Dutheil Michael
Published: March 2009

Zirconia can be considered to be one of the most important ceramic materials because of its large range of industrial applications (catalysis, coatings, spacecraft shielding, paint additives, oxygen sensors, fuel cells, nuclear fuel matrices, an alternative high permittivity material to replace silicon oxide as a gate dielectric in MOS devices). Many of these applications require the use of zirconia in a nanocrystalline form. It is now well established that a monoclinc to tetragonal phase transition is trigged by the grain size of zirconia. The mechanism of this phase transition in zirconia is not yet clearly understood. Several experiments point out that the thermodynamic properties of nanocrystalline solids are particle-size dependent. Size-related effects like the reduction of the melting temperature and displacement of the phase boundaries can be predicted. Zirconia can be considered a textbook example for describing these effects. In this ceramic several polymorphic transformations occur with the change of external parameters (Temperature, pressure, …). In this paper, the behaviour of the tetragonal to monoclinic martensitic phase transition within Landau theory framework in particular will be discussed, pointing out the peculiar effects related the small grain size of the nanoparticles. Neutron diffraction experiments will illustrate the of these arguments and provide some insight to the understanding of the behaviour of nanocrystals in severe environments, such as in nuclear reactors or in space applications.
New Nano-Sized Sensing Drug and Its Clinical Application
Authors: Ion Rodica-Mariana , Brezoi Dragos-Viorel
Published: March 2009

Nanomedicine is the application of nanotechnology to the diagnosis and treatment of human disease. This discipline has the potential to change medical science dramatically, for example as demonstrated by an innovation in cancer imaging that uses novel diagnostic agents synthesized from nanoparticles. Some research on cluster-based materials for future medical applications is described in this paper. The design of a multifunctional photosensitive particle that is stable and highly efficient will be key to this novel medical application and especially in photodynamic treatment (PDT). Three consecutive processes occur during the PDT treatment: initial consumption of oxygen through the photodynamic process; pathophysiologic alterations in regional blood supply (hypoxia) and total vascular occlusion (ischemia). The effect of a new drug TiO2/TSPP was studied work. Cancer cells were implanted under the skin of mice to cause tumors. When the size of the tumor grew to about 0.5 cm, it was injected a solution containing fine particles of TiO2/TSPP. After 2 or 3 days, the skin was cut to expose the tumor and irradiated. The treatment clearly inhibited the tumor growth. A further marked antineoplastic effect was obtained.
Nanostructure, Nanochemistry and Grain Boundary Conductivity of Yttria-Doped Zirconia
Authors: Rizea A. , Raulot Jean Marc , Petot C. , Petot-Ervas Georgette , Baldinozzi Gianguido
Published: March 2009

This work was directed at a comprehensive study of the role of the nanostructure and nanochemistry on the transport properties of yttria-stabilized zirconia. Alumina additions lead to a decrease of sgb when the samples have clean grain boundaries, while sgb goes through a maximum in samples having glassy grain boundaries. The differences were attributed to the strong interaction between Al2O3 and SiO2 impurities leading to a glassy phase depletion at the grain-boundaries, due to a change in wettability. Moreover, XPS analyses show that Si and Y segregate near these interfaces according to a kinetic demixing process, explaining why a faster cooling rate after sintering has a beneficial effect on sgb.