bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Particle Interaction on Agglomeration of Silica-Based CMP Slurries
Authors: Sorooshian A. , Ashwani R. , Choi H.K. , Moinpour M. , Oehler A. , Tregub A. 
Published: April 2011

AbstractChemical Mechanical Planarization has become a method of choice for planarization of metal and oxide layers in microelectronics industry. A CMP process includes up to 16 variables that need to be controlled to achieve a stable CMP process [1]. One of the major variables in CMP is related to slurry compositions. In particularly, a uniform distribution of the sizes of the abrasive particle in slurry is crucial for a stable CMP performance. The agglomerates can be unstable, since their size depends on addition of chemical additives and shearing during the CMP process.In this work, the authors studied agglomeration of the fumed and colloidal silica-based slurries using dynamic rheometry, zeta potential tests, and an accusizer.Slurry viscosity, determined using a steady state rheometry, was correlated to the particle charge, characterized by zeta potential, and to the particle sizes obtained using the particle size analyzer. Additionally, rheometer was used for slurry shearing to study effect of shear on slurry characteristics. Particle agglomeration due to slurry shearing and storage was observed and corroborated using rheometry, zeta potential, and particle size measurements.
Modeling CMP Transport and Kinetics at the Pad Groove Scale
Authors: Muldowney Gregory P. 
Published: April 2011

AbstractA 3-D fluid flow and kinetics model of the full pad-wafer gap of a commercial CMP machine, including both grooves and land area flow properties, was developed to research the influence of these essential pad features at a scale not previously studied. Concentric circular grooves of two different dimensions were examined. Heat transfer and chemical reaction rates at the wafer surface were studied by including a combined frictional/chemical heat release model and firstorder kinetics for slurry activity. Results revealed sharp variations in velocity between the grooves and land areas, and a strong impact of groove depth and width on transient slurry mixing in the pad-wafer gap. These effects were more pronounced at higher polish pressures. Flow patterns in individual grooves beneath the rotating wafer were highly variable from one location to another such that fluid pathlines were dissimilar point to point even within the same groove. The effects of pad and wafer rotation, amplified by the unequal flow resistances of grooves and land areas, led to features in the steady-state temperature and concentration profiles at the same spacing as the groove pitch. This unusual finding identified a direct mechanism by which polish irregularities may be formed at the scale of the grooves.
Characterizing STI CMP Processes with an STI Test Mask Having Realistic Geometric Shapes
Authors: Xie Xiaolin , Park Tae , Boning Duane , Smith Aaron , Allard Paul , Patel Neil 
Published: April 2011

AbstractChemical mechanical polishing (CMP) has become the enabling planarization method for shallow trench isolation (STI) of sub 0.25μm technology. CMP is able to reduce topography over longer lateral distances than earlier techniques; however, CMP still suffers from pattern dependencies that result in large variation in the post-polish profile across a chip. In the STI process, insufficient polish will leave residue nitride and cause device failure, while excess dishing and erosion degrade device performance.Our group has proposed several chip-scale CMP pattern density models [1], and a methodology using designed dielectric CMP test mask to characterize CMP processes [2]. The methodology has proven helpful in understanding STI CMP; however, it has several limitations as the existing test mask primarily consists of arrays of lines and spaces of large feature size varying from 10 to 100 μm. In this paper, we present a new STI characterization mask, which consists of various rectangular, L-shape, and X-shape structures of feature sizes down to submicron. The mask is designed to study advanced STI CMP processes better, as it is more representative of real STI structures. The small feature size amplifies the effects of edge acceleration and oxide deposition bias, and thus enables us to study their impact better. Experimental data from an STI CMP process is shown to verify the methodology, and these secondary effects are explored. The new mask and data guide ongoing development of improved pattern dependent STI CMP models.
A High Index Contrast Silicon Oxynitride Materials Platform for Er-doped Microphotonic Amplifiers
Authors: Saini Sajan , Sandland Jessica G. , Eshed Anat , Sparacin Daniel K. , Negro Luca Dal , Michel Jurgen , Kimerling Lionel C. 
Published: April 2011

AbstractEr-based optical amplification continues to be the ideal low noise, WDM crosstalk free, broadband candidate for waveguide amplifiers. Design analysis of the applicability of Er-Doped Waveguide Amplifiers (EDWAs) for micron-scale integrated photonics in a planar lightwave circuit concludes: (i) an >80× increase in gain efficiency, and (ii) a >40×increase in device shrink can be realized, for a high index contrast EDWA (with a core-cladding index difference of δn=0.1↔0.7), compared to a conventional Er-doped fiber amplifier. The materials challenge now is to establish a robust materials system which meets this high index difference design requirement while simultaneously leveraging the capability of silicon (Si) processing: a host platform for EDWAs must be found which can integrate with Si Microphotonics. Silicon nitride (Si3N4), silicon oxide (SiO2) and a miscible silicon oxynitride alloy (SiON) of the two meet this materials challenge. We present the results of reactive and conventional magnetron sputtering based materials characterization for this high index host system. Room temperature and 4 K photo-luminescence studies for annealed samples show the reduction of non-radiative de-excitation centers while maintaining an amorphous host structure. Atomic force microscopy shows less than 1 nm peak-to-peak roughness in deposited films. Prism coupler measurements show a reliable reproducibility of host index of refraction with waveguide scattering loss <2 dB/cm. We conclude that the SiON host system forms an optimal waveguide core for an SiO2-clad EDWA. Initial gain measurements show a gain coefficient of approximately 3.9 dB/cm.
Optical and structural investigation on the energy transfer in a multicomponent glass co-doped with Si nanoaggregates and Er3+ ions
Authors: Enrichi Francesco , Mattei Giovanni , Sada Cinzia , Trave Enrico , Pacifici Domenico , Franzò Giorgia , Priolo Francesco , Iacona Fabio , Prassas Michel , Falconieri Mauro , Borsella Elisabetta 
Published: April 2011

AbstractThe enhancement of the Er3+ ions photoluminescence (PL) emission at 1.54 μm in a Si and Er co-implanted aluminosilicate glass is investigated in details. Post-implantation annealing has been performed to recover the damage induced by the implantation process and to promote Si aggregation. It is shown that 1h treatment in N2 atmosphere is not sufficient to induce Si precipitation for the investigated temperatures, up to 500°C. Nevertheless, the most intense Er3+ PL emission at 1.54 μm is achieved at 400°C. Such emission has been investigated by pumping in and out of resonance. The results suggest that good energy transfer mediators could be small Si aggregates and not only crystalline clusters. The effective excitation cross section of Er3+ ions has been measured in the best performing sample yielding a value of ∼ 2 × 10−16 cm2, many orders of magnitude higher than the direct absorption cross section of Er3+ ions: about 10−21 cm2 in this glass. The structural and optical properties of this material are discussed and compared to those found for a standard silica substrate.
Optical Spectroscopy of Silicon-On-Insulator Waveguide Photonic Crystals
Authors: Bajoni D. , Galli M. , Belotti M. , Paleari F. , Patrini M. , Guizzetti G. , Gerace D. , Agio M. , Andreani L.C. , Chen Y. 
Published: April 2011

AbstractWe report on a complete optical investigation on two-dimensional silicon-on-insulator (SOI) waveguide photonic crystals obtained by electron beam lithography and reactive ion etching. The dispersion of photonic modes is fully investigated both above and below the light-line by means of angle- and polarization-resolved micro-reflectance and attenuated total reflectance measurements.The investigated samples consisted in a) large area (300 × 300 μm2) two-dimensional (2D) triangular lattices of air holes containing repeated line–defects; b) small area triangular lattices of holes with different number of periods and /or line defects integrated in a ridge type waveguide structure.In the case of large area samples, variable-angle reflectance and ATR is measured from the sample surface in a wide spectral range from 0.2 to 2 eV both in TE and TM polarizations. The sharp resonances observed in the polarized reflectance and ATR spectra allow mapping of the photonic dispersion of both radiative and guided modes. Experimentally determined and compared to those calculated by means of an expansion on the basis of the waveguide modes.In the case of ridge type waveguide-integrated photonic crystals, transmission is measured in the 0.9-1.7 eV spectral range by an edge-coupling technique. Transmission spectra exhibit significant attenuation corresponding to the photonic gaps along the Γ–M and Γ–K directions respectively, even when a small number of hole periods is integrated in the ridge waveguide. Good agreement is obtained by comparing the measured transmission spectra with the calculated photonic bands.
Low loss silica waveguides containing Si nanocrystals
Authors: Garcia C. , Garrido B. , Pellegrino P. , Morante J.R. , Melchiorri M. , Daldosso N. , Pavesi L. , Scheid E. , Sarrabayrouse G. 
Published: April 2011

AbstractWe study the optical and structural properties of rib-loaded waveguides working in the 600-900 nm spectral range. A Si nanocrystal-rich SiOx with Si excess nominally ranging from 10 to 20% forms the active region of the waveguide. Starting materials were fused silica wafers and 2 μm-thick SiO2 thermally grown onto Si substrate. Si nanocrystals were precipitated by annealing at 1100°C after quadruple Si ion implantation to high doses in a flat profile. The complete phase separation and formation of Si nanocrystals were monitored by means of optical tools, such as Raman, optical absorption and photoluminescence. Grain size distribution was obtained by electron microscopy. The actual Si excess content was obtained by X-ray photoelectron spectroscopy. The rib-loaded structure of the waveguide was fabricated by photolitographic and reactive ion etching processes, with patterned rib widths ranging from 1 to 8 μm. M-lines spectroscopy measurements provided a direct measurement of the refractive index and thickness of the active layers versus Si excess. When coupling a probe signal at 780 nm or 633 nm into the waveguide, an attenuation of at least 11 dB/cm was observed. These propagation losses have been attributed to Mie scattering, waveguide irregularities and direct absorption by the silicon nanocrystals.
Structural properties of Si nanoclusters produced by thermal annealing of SiOx films
Authors: Boninelli Simona , Iacona Fabio , Bongiorno Corrado , Spinella Corrado , Priolo Francesco 
Published: April 2011

AbstractThe structural properties of Si nanoclusters embedded in SiO2, produced by high temperature annealing of SiOx films, have been investigated by energy filtered transmission electron microscopy. The presence of amorphous nanostructures, not detectable by using dark field transmission electron microscopy, has been demonstrated. By taking into account also this contribution, a quantitative description of the evolution of the samples upon thermal annealing has been accomplished. In particular, the nanocluster mean radius and the density of amorphous and crystalline clusters have been determined as a function of the annealing temperature.
Ordered Micro-Particle Structures in a Liquid Crystal: Formation and Physical Properties
Authors: Zhang Ke , Glushchenko Anatoliy , West John L. 
Published: April 2011

AbstractOrdered colloids are of great scientific and practical interests. Liquid crystals offer enhanced ways of producing and stabilizing these complex structures. We therefore studied the rheological and electro-rheological properties of the structured colloids as a means of probing this stabilization. We found that the mechanical properties of the colloids and stability of their 3D structures can be controlled by the particles size and distribution. In addition, when an electric field is applied, we observed an increase in the apparent viscosity with saturation at high electric fields. This effect depends on the shear rate and temperature. The results are also compared with the published data for the viscosity measurements of pure liquid crystals and isotropic colloids. While we are only beginning to understand the details of these complex colloids we expect they will find a wide variety of applications.
Integrated Optics/Electronics Using Electro-Optic Polymers
Authors: Dalton Larry R. 
Published: April 2011

AbstractOrganic electro-optic materials afford the realization of devices with terahertz bandwidths, providing bandwidths are not limited by resistive losses in metal electrodes. Recent realization of electro-optic coefficients (at telecommunication wavelengths) on the order of 200 pm/V permits construction of devices with operating voltage requirements of 1 volt or less. In like manner, substantial progress has been made in both understanding and improving thermal and photostability suggesting that organic electro-optic materials can meet Telacordia standards. However, one of the most intriguing advances afforded by organic materials is their processability including the ability to be integrated with diverse materials. This communication discusses both the systematic improvement, by theoretically-inspired rational design, of relevant material properties and the development of a variety of new processing methodologies, including soft lithography methods, for the fabrication of stripline, cascaded prism, and ring microresonator devices. The fabrication of flexible devices is also discussed.
Reliable InGaAsP/GaAs 40W lasers grown in solid source MBE with phosphorus-cracker
Authors: Kuang G. K. , Hernandez I. , McElhinney M. , Zeng L. , Caliva B. , Walker R. 
Published: April 2011

AbstractLaser structures with InGaAsP quantum well were grown on GaAs substrates in a solid source MBE system. Threshold current density Jth as low as 290A/cm2 and slope efficiency as high as 0.68W/A per facet were obtained for uncoated laser chips at 25°C. After 857 hours burn-in at 47A (corresponding to around 47W) at room temperature, power degradation rate was measured to be less than 3×10−6/h.
The Influence of Processing Parameters on Photoluminescent Properties of Ba2ZnS3:Mn Phosphors by Double-Crucible Method
Authors: Lin Yu-Feng , Chang Yen-Hwei , Tsai Bin-Siang 
Published: April 2011

AbstractRed light emitting of Mn2+doped Ba2ZnS3phosphor powders have been synthesized by double-crucible method at different thermal treatments. XRD results indicate that the raw materials are completely sulfurized above 950°C, and the Ba2ZnS3: Mn2+powders don't change its orthorhombic crystal structure with increasing doping concentration from 0 to 0.8 mol%. The photoluminescence of Ba2ZnS3: Mn2+powders fulfilled the most efficient emission at the excitation wavelength λex=358 nm and showed the red emission light with peak wavelength λem=627nm at the doping concentration of Mn2+ion between 0.2 and 0.8 mol%. The high-luminance red emission results from the4T1(4G)—6A1(6S) transition in the Mn2+ion. Ba2ZnS3: Mn2+phosphors synthesized by double-crucible method have broad emission spectra (550nm∼750nm) with FWHM (full width at half maximum broadband) about 66nm. In our research, the Ba2ZnS3doped with 0.4 mol% Mn2+has the highest luminescent intensity as thermal treatment at 950°C for 16 hours and the CIE coordinate is x=0.66, y=0.33.
Nanochemistry of Ceria Abrasive Particles
Authors: Gilliss Shelley R. , Bentley James , Barry C. 
Published: April 2011

AbstractSurfaces of ceria (CeO2) particles have been studied by electron energy-loss spectroscopy in a field-emission gun scanning transmission electron microscope. All the ceria particles analyzed contained Ce3+ at the surface. Rare-earth impurities such as La were enriched at the surface and were observed for particles ranging from tens to hundreds of nanometers in size. The oxidation state of the cerium ion is measured from the Ce M5/M4white-line intensity ratio.
An Optimized Synthetic Route for the Preparation of Water-Soluble Nanomagnetic Conducting Polyaniline with High Processability
Authors: Koul Sarswati , Nathan Arokia 
Published: April 2011

AbstractThe synthesis of water soluble nanomagnetic conducting polyaniline with an average particle size of 8nm ±1nm is presented. The particle growth morphology during reaction kinetics was controlled by using polyelectrolyte mediated dual oxidant-dopant system. The synthesis was carried out in a single reactor and the entire synthetic approach follows the principles of green chemistry. Dual oxidant-dopant system offers a solvent less chemical route for the synthesis of nanomagnetic polyaniline with maximum yield production.
Transport Properties of Magnetic Nanowires with Multiple Constrictions Formed by FIB
Authors: Liu Tie , Wu Yihong 
Published: April 2011

AbstractNi nanowires were fabricated by electrochemical deposition in the pores of alumina filtration membranes, with the diameter around 200nm. To study the magnetic and electrical properties of Ni nanowires, individual nanowire was selected and connected with metal electrodes. Single and multiple constrictions were formed on the nanowires by focused ion beam (FIB). The wires were further thinned using oxygen plasma oxidation. Magnetoresistance curves were studied and compared before and after FIB trimming and oxidization.
Metallic and Semiconducting Nanowires from Single Wall Carbon Nanotubes
Authors: Sivakumar Kousik , Lu Shaoxin , Panchapakesan Balaji 
Published: April 2011

AbstractThe focus of today's research has largely shifted from macro scale to micro scale and further to nano scale. The reason being the desire to realize quantum size effects in devices that has long eluded scientists around the world alike. With the discovery of nanoparticles, nanowires, and nanotubes, the ability to realize these effects practically into devices has increased manifold. Integration of carbon nanotubes with different types of functional materials may become mandatory in the future for electronics and sensing applications and in this sense, nucleation, growth and evolution of the structure of metallic and semiconducting materials on carbon nanotubes may be necessary. Further, it also provides opportunities to do fundamental research on understanding the structure-property relationships of these nanowires using carbon nanotubes. In this paper, we present a technique to form metallic and semiconducting nanowires using carbon nanotubes themselves as templates. Nanowires of silver and platinum have been fabricated by the electric field assisted deposition of nano particles of these metals on single walled carbon nanotubes. SEM and TEM investigations have shown the dimensions of the nanowires to be dependent only on the size of the nanoparticles, 10 - 100 nm in our case. The silver nanowires exhibited linear current – voltage characteristics whereas the platinum nanowires exhibited non-linear characteristics beyond a certain bias. This technique provides a high degree of selectivity by manipulating the charges on the surface of the nanotubes, which enables the deposition of metals only on the nanotubes and not anywhere else. The versatility of this technique allows for the fabrication of different types of metallic and semiconducting nanowires at the same dimensions as carbon nanotubes.
Site Selective Electrodeposition of Metals and Conductive Polymer Nano-Structures on Isolated Carbon Nanopipes Using Electric Fields
Authors: Bradley Jean-Claude , Babu Sundar , Ndungu Patrick 
Published: April 2011

AbstractWe report the successful application of bipolar electrochemistry for depositing metals and conducting polymer nano-structures on isolated template-grown carbon nanopipes (CVD-CNP). Metals such as tin, cobalt and nickel were reduced electrochemically at the tips of isolated CVD- CNP from their chloride or nitrate salts. Polypyrrole dendrites could also be grown on both ends of selected CVD-CNP. The potential applications of thus encapsulated CVD-CNP in nano- fluidics and other areas will be discussed.
Functionalized Polymeric Nanoparticles
Authors: Sussman Eric , Clark Michael , Shastri V. Prasad 
Published: April 2011

AbstractSurface-functionalized polymeric nanoparticles (NP) are a versatile medium for drug delivery and imaging. The surface functionality is typically exploited to introduce molecules such as polymers and biomolecules to improve cellular localization, DNA binding and circulation. NP bearing surface functionality are typically prepared from polymers possessing functionalizable backbones or by layer-by-layer assembly of polyelectrolytes onto unmodified particles. We have developed a process to produce functionalized polymeric NP in a single step using non-functionalized polymers. This is achieved by the entrapment of polymeric functional moieties from an aqueous phase in a rapidly solidifying polymer core. NP were characterized using light scattering, scanning electron microscopy, zeta potential (ζ) measurement, fluorescent microscopy, and X-ray photoelectron spectroscopy (XPS). Stable NP ranging in diameter from 70 to 400nm with narrow polydispersity (PDI) can be produced by this process. The presence of functional moieties on the NP surface was verified by isoelectric point measurement and XPS. We foresee a number of uses for these functionalized nanoparticles, including drug delivery and modification of hard and soft material surfaces (both synthetic and biological) for tissue engineering.
Magnetic Properties and Fabrication of Monodisperse FePd Nanoparticles
Authors: Hou Yanglong , Kondoh Hiroshi , Ohta Toshiaki 
Published: April 2011

AbstractThe combination of 1-adamantanecarboxylic acid and tri-alkylphosphine was applied to produce monodisperse FePd nanoparticles by the polyol reduction of palladium acetylacetonate and thermally decomposition of iron pentacarbonyl. Images of high resolution transmission electron microscopy (TEM) and X-ray diffraction (XRD) data indicate a highly monodisperse and crystalline nature of the FePd nanoparticles. Magnetic studies performed by Quantum Design SQUID magnetometer show that FePd (16nm) nanoparticles are superparamagnetic at room temperature.
Magnetic nanowires and Y-Junctions
Authors: Kim Na Hyoung , Stadler Bethanie 
Published: April 2011

AbstractSelf-assembled nanopore templates were fabricated by anodizing aluminum in several electrolytes under specially selected conditions. The size of the nanopores was controlled, and many sizes were fabricated. Y-junction nanopore templates were also fabricated using a two-step anodization. Magnetic nanowires and Y-junction nanowires were then fabricated by electrochemical deposition of magnetic material into the nanopore templates and Y-junction nanopore templates. The magnetic properties of nanowires were investigated by VSM and compared.