bluuebunny/crossref_metadata_2025_split huggingface dataset:
Noble Gas Induced Defects in Silicon
Authors: Weber J. , Estreicher S.K. 
Published: April 2011

AbstractLow energy bombardment of silicon with noble gas ions generates a family of defects with characteristic low-temperature photoluminescence spectra. The defect distribution up to one gtm below the sample surface indicates an unusually enhanced migration mechanism during the bombardment of the specimen. Annealing the samples above 500 °C leads to the disappearance of the photoluminescence spectra and the formation of new, more extended defects, which are excellent gettering sites for transition metals, in particular copper. Systematic calculations of noble-gas vacancy interactions imply a model for the photoluminescing defect where the noble gas atom is trapped by a divacancy.
Highly Efficient Nitrogen Doping Into GaAs Using Low-Energy Nitrogen Molecular Ions
Authors: Shima Takayuki , Makita Yunosuke , Kimura Shinji , Sanpei Hirokazu , Fukuzawa Yasuhiro 
Published: April 2011

AbstractLow-energy N2+ molecular-ions were irradiated during the epitaxial growth of GaAs. Ion acceleration energy and ion beam current density were varied in the range of 30-200 eV and 3-37 nA/cm2, respectively. GaAs growth rate was kept constant at 1µm/ h and the thickness of N-doped GaAs layer was about 1 µm. N concentration was obtained by using secondary ion mass spectroscopy. Strong N-related emissions were observed in the low-temperature photoluminescence spectra, which indicates that N atom is efficiently substituted at As site and is optically active as an isoelectronic impurity
Crack Propagation Experiments on Flip Chip Solder Joints
Authors: Wiese S. , Feustel F. , Rzepka S. , Meusel E. 
Published: April 2011

ABSTRACTThe paper presents crack propagation experiments on real flip chip specimens applied to reversible shear loading. Two specially designed micro testers will be introduced. The first tester provides very precise measurements of the force displacement hysteresis. The achieved resolutions have been I mN for force and 20 nm for displacement. The second micro tester works similar to the first one, but is designed for in-situ experiments inside the SEM. Since it needs to be very small in size it reaches only resolutions of 10 mN and 100nm, which is sufficient to achieve equivalence to the first tester. A cyclic triangular strain wave is used as load profile for the crack propagation experiment. The experiment was done with both machines applying equivalent specimens and load. The force displacement curve was recorded using the first micro mechanical tester. From those hysteresis, the force amplitude has been determined for every cycle. All force amplitudes are plotted versus the number of cycles in order to quantify the crack length. With the second tester, images were taken at every 10th … 100th cycle in order to locate the crack propagation. Finally both results have been linked together for a combined quatitive and spatial description of the crack propagation in flip chip solder joints.
Quantitative Measurements of Segregation In Co-Cr-X Magnetic Recording Media by Energy-Filtered Transmission Electron Microscopy
Authors: Bentley J. , Wittig J.E. , Nolan T.P. 
Published: April 2011

AbstractReliable core-loss spectroscopic methods have been developed for mapping elemental segregation in Co-Cr-X magnetic recording media by energy-filtered transmission electron microscopy. Extraction of quantitative compositions at a spatial resolution approaching 1 nm involves sophisticated treatments for diffraction contrast, variations in specimen thickness, and closely-spaced oxygen K and chromium L23 ionization edges. These methods reveal that intergranular chromium levels are ∼25 at.% for random-angle boundaries and ∼15 at.% for 90° boundaries in films of Co84Cr12Ta4 d.c. magnetron sputtered at 250°C.
Macroscopic Probing of the Joint Between Metals in Mr Heads
Authors: Geng Jibin , Yan X. , Zhang X.X. , Zhang Xiaofeng , Wang N. , Fung K.K. 
Published: April 2011

AbstractDuring the wafer manufacturing process of magnetoresistive (MR) heads which are widely used in Hard Disk Drives, the metal leads are deposited on both sides of the MR sensing element through the photoresist masks. Due to the shadowing effect of the photoresist, there may be some contamination at joint interfacial region even after ion etching. This introduces additional contact resistance and causes some region of the sensing element to be unpinned. As the geometry of the sensor element decreases, and the contamination, located in regions of few thousands of angstroms, is becoming more severe for MR head than ever. In this paper, we developed a systematic method to evaluate the contact resistance between the two metal layers. A comparison was made between the magnetic read width and the physical width. Finally TEM analysis successfully revealed the interfacial junction contamination.
Interparticle Interaction Effects in Nonmiscible CoAg Thin Films With High Co Concentration
Authors: Butera A. , Barnard J. A. 
Published: April 2011

AbstractA series of Co-rich CoAg heterogeneous thin films, with Co concentrations greater than 65 % volume fraction and film thickness in the range 5 nm - 50 nm, was prepared by dc magnetron sputtering. Annealing in high vacuum (P < 3x10-7 Torr) above 400°C was necessary to promote phase separation between the two elements. Maximum room temperature coercivities, Hc ∼ 900 Oe, were obtained at a thickness of 20 nm for CoAg 70:30 vol % films. These coercivities are almost two orders of magnitude larger than the values observed in as-deposited films. The concentration of maximum coercivity, that is usually associated to the threshold for magnetic percolation, is much higher than the 40-50 vol % commonly observed in bulk granular materials. The shift in the magnetic percolation limit was related to the reduced dimensionality of the very thin films. Coercivity was found to vary both with film composition and with thickness. Delta M curves and time decay (magnetic viscosity) measurements were done to determine the interparticle interactions and the activation volumes. A maximum in the remanent coercivity (coincident with the maximum in Hc) was found for a film thickness φ ∼ 15-20 nm in all the alloys. At this same thickness a negative minimum in the interparticle interaction parameter α (indicating that the particle interactions favor the demagnetized state) was observed. The absolute value of a increases for larger Co concentrations. The irreversible susceptibility is an increasing function of film thickness and the magnetic viscosity has a minimum for φ ∼ 15-20 nm. The activation volume also increases with thickness, changing from (15 nm)3 to (40 nm)3 for the more diluted alloys, values similar to the average particle size determined by transmission electron microscopy.
Faraday Effect Devices, Optical Isolators
Authors: Wilson Donald K. 
Published: April 2011

AbstractAlthough discovered over 150 years ago, it was not until the 1970's that materials were developed that enabled magneto-optic (Faraday) effect devices of practical sizes. These developments are: magneto-optic materials with high Verdet constants, and the rare-earth magnet materials, capable of extremely high magnetic fields.The magneto-optic effect has enabled development of equipment used in diverse laser applications, from industrial use to fiber-optic telecommunications.The principle of operation of optical isolators and circulators is described herein, as well as descriptions of critical components in such equipment, such as the polarizers and the magnets.
Steel and Titanium Hollow Sphere Foams
Authors: Hurysz K. M. , Clark J. L. , Nagel A. R. , Hardwicke C. U. , Lee K. J. , Cochran J. K. , Sanders T. H. 
Published: April 2011

ABSTRACTMetal hollow sphere foams are fabricated by bonding millimeter sized metal alloy hollow spheres at points of contact. The spheres are formed as powder shells from slurries. For stainless steel spheres, the starting powder is a mixture of iron and chromium oxide. Thermal treatment in hydrogen reduces the oxides to Fe/Cr alloys with less than 2% porosity in sphere walls. The nominal composition is close to that of 405 stainless. Carburization in CO/CO2 atmosphere followed by heat treatment produces foams of either 410 or 420 type stainless steels depending on carbon content. Compressive stress-strain behavior was measured on point contact bonded stainless foams both before and after carburization. Hardness measurements on steel sphere walls were used to estimate the yield strength. Relative strengths of the foams were positioned between open and closed cell models. This was encouraging because bonding in the foams was less than optimum and the hollow sphere walls contained defects. As processing improves, strengths should increase. To produce titanium alloy spheres, the starting powder is titanium alloy hydride. Thermal treatment in an inert atmosphere decomposes the hydride and sinters the titanium powder in the sphere walls to greater than 96% relative density. Both titanium and Ti-6V-4V spheres and foams have been produced. Oxygen contents are a concern for titanium compositions and processing is being altered to reduce oxygen levels to increase ductility
Meeting RTP Temperature Accuracy Requirements: Measurement and Calibrations at Nist
Authors: Lovas F. J. , Tsai B. K. , Gibson C. E. 
Published: April 2011

ABSTRACTAlthough radiometric temperature measurement in rapid thermal processing (RTP) tools has substantially improved in terms of repeatability and uniformity, it still remains a technical challenge. The 1999 requirements of 180 nm line width technology in the 1997 National Technology Roadmap for Semiconductors (NTRS) imply an uncertainty of ± 2 °C in temperature measurement, which will continue the challenge in temperature measurement. In this paper we will discuss the NIST absolute radiometric temperature calibration, measurements, and uncertainty analysis.
Alternative Gate Dielectrics with BST/TIO2/(Barrier Oxide) Stacked Structure
Authors: Jeon Yongjoo , Lee Byoung Hun , Zawadzki Keith , Qi Wen-Jie , Lee Jack C. 
Published: April 2011

ABSTRACTBST/TiO2/(Barrier Layer) stacked dielectric structure has been proposed for ultra thin (<20Å) gate dielectric application to overcome the direct tunneling current problem of Si02. To characterize the alternative dielectrics, MIM and MIS capacitors were fabricated. TiO2 is believed to prevent BST and Si from reaction and interdiffusion while TiC2 itself is stable due to the strong binding energy. For better interfacial quality of TiO2/Si interface, proper barrier layer is needed between TiO2 and Si. Optimization of this barrier layer was performed by RTP grown N20 oxide and self-grown interfacial oxide layer with various annealing conditions. To monitor these barrier layers, TEM and electrical analysis were performed. From TEM observation, it was found that interfacial layer was formed in every sample whether it was intentionally grown or not. It was observed that the leakage current of Pt/TiO2/Si dramatically increased after 700'C or higher temperature annealing. This might be related to the transition of crystal structure of TiO2 from anatese to rutile at about 700°C[1]. It was also found that both Pt/BST/TiO2/Si and Pt/TiO2/Si showed lower leakage current compare to the conventional NO oxide at comparable equivalent SiO2 thickness. These results imply that these materials hold some promise as alternatives of pure SiO2 in very thin range.
Chemical Stability of Advanced Metal Gate and Ultra-thin Gate Dielectric Interface During Rapid Thermal Annealing
Authors: Claflin B. , Binger M. , Lucovsky G. 
Published: April 2011

ABSTRACTThe chemical stability of the compound metals TiNx and WNx on SiO2 and SiO2/Si3N4 (ON) dielectric stacks is studied by on-line Auger electron spectroscopy (AES) following sequential rapid thermal annealing treatments of 15 - 180 s up to 850 °C. The TiNx/SiO2 interface reacts at 850 °C and the reaction is kinetics driven. The TiNx/Si3N4 interface is more stable than TiNx/SiO2 even after a 180 s anneal at 850 °C. WNx is stable below 650 °C both on SiO2 and Si3N4, but above this temperature the film changes, possibly due to crystallization or interdiffusion. The changes in the WNx film are not controlled by kinetics. The compound metals are chemically more stable at elevated temperatures than pure Ti or W on SiO2.
Simulation of Rapid Thermal Annealed Boron Ultra-Shallow Junctions in Inert and Oxidizing Ambient
Authors: Lerch W. , Glück M. , Stolwijk N. A. , Walk H. , Schäfer M. , Marcus S. D. , Downey D. F. , Chow J. W. , Marquardt H. 
Published: April 2011

ABSTRACTRapid Thermal Annealing (RTA) is indispensable for the formation of ultra-shallow source/drain junctions. To improve the annealing conditions, a fundamental understanding of the influences on the diffusion/activation process is necessary. Ion implantations of 1 keV boron at a dose of Φ≈1 I.1015 cm-2 are annealed in a SHS2800E RTP-system under controlled concentrations of oxygen in nitrogen ambient (0-1 ppm up to 1%). Concentration-depth profiles, measured by Secondary Ion Mass Spectroscopy (SIMS), are simulated within the framework of the kickout model involving diffusion enhancement via supersaturation of silicon self-interstitials. The validity of this interpretation is supported by the simulated results which are in good agreement with expenimental data. After RTA for 10 s at 1050°C the junctions are varying within a range of 800Å to 1400Ådepending on the annealing ambient. The results of the simulation yield finite values of self-interstitial supersaturation as a function of the oxygen concentration.
Novel Applications of Rapid Photothermal Chemical Vapor Deposition
Authors: Singh R. , Parihar V. , Chen Y. , Poole K. F. , DeBoer S. , Thakur R. P. S. , Sharangpani R. , Vasudev P. K. 
Published: April 2011

ABSTRACTIn recent years, we have developed rapid photothermal chemical vapor deposition (RPCVD) technique. In RPCVD, photons with wavelength between 100–400 nm irradiate the side of the substrate where chemical reactions take place. RPCVD provides materials with minimum microscopic defects and minimum thermal and residual stress. Due to these features and low processing time and low processing temperature capabilities, RPCVD is ideal for process integration and manufacturibility. In this paper we have presented the results of high K and low K dielectrics. Detailed electrical, structural, characterization, and stress measurements combined with reliability of data indicate that RPCVD has the potential of meeting advanced manufacturing needs of semiconductor and other related industries.
Iron-Silicate Glassy Films by Sol-Gel Conversion Induced by Rapid Thermal Processing
Authors: Van De Leest René E. , Roozeboom Fred 
Published: April 2011

ABSTRACTThe sol-gel system iron triethoxide - tetraethylorthosilicate (TEOS) with the Fe/Si atomic ratio ranging from 0 to 1 has been investigated. Our study leads to the conclusion that the annealing method of the hydrolyzed precursor film determines the type of solid film formed. Annealing by Rapid Thermal Processing (RTP) with its high heating and cooling rates yields amorphous, glassy iron silicate films. These films result from polycondensation reactions between Si-OH and Fe-OH groups of the hydrolyzed precursors forming Fe-O-Si and Si-O-Si bonds. These bonds show a characteristic vibration band in FTIR spectra, which is most intense for Fe/Si = 1, and shifts for increasing Fe/Si ratio from 1073 down to 965 cm-1.The iron silicate film with Fe/Si =1 obtained by RTP displays an optical absorption band around 320 nm, which indicates that Fe3+-ions have a tetrahedral coordination similar to the Si4+-ions in Si02 and glass with tetrahedrally coordinated silicon and iron ions linked by bridging oxygen atoms. The films, typically 0.1 μm thick, annealed by RTP have a smooth, mechanically hard surface. This glassy structure can be formally presented as FeSiOx. Conventional furnace heating with low heating/cooling rates yields nanocrystalline films with predominantly Si-O-Si bonding in grains with sizes below 40 nm. More structural and chemical investigation is needed to elucidate the details of the structure and the formation mechanism of the amorphous compound, but we can conclude that the cooling rate has a direct effect on the degree of non-crystallinity of the compound. The high cooling rate of RTP will retain the Fe-O-Si bonds formed in a state of inequilibrium, and “quench” them in an amorphous, metastable glass compound, whereas slow cooling gives rise to nanocomposite film formation.
Three Dimensional Simulation of the Morphological Evolution of a Strained Film on a Thick Substrate
Authors: Chiu Cheng-hsin 
Published: April 2011

AbstractThis paper presents a three-dimensional simulation for the surface evolution of a strained film on a thick substrate. The simulation shows that an initially random morphology will first transform into a profile dominated by two-dimensional ridges, and then into a three-dimensional island surface. The simulation also demonstrates that the ridge-island transition is a kinetic process which can be delayed by changing the initial morphology.
The Origin of Mis-Oriented Diamond Grains Nucleated Directly on (001) Silicon Surface
Authors: Zhang R.Q. , Zhang W.J. , Sun C. , Jiang X. , Lee S.-T. 
Published: April 2011

AbstractThe origin of mis-oriented diamond grains frequently observed in heteroepitaxial diamond films on (001) silicon surfaces was studied. By statistically analyzing the in-plane rotation angles of diamond grains in scanning electron microscopy observations, it was found that the distribution of the grain orientation is not random and two satellite distribution peaks at about 20° and 30° accompany the main distribution peak at zero degree referenced to the <110> direction of substrate. The interface structure corresponding to the main distribution peak at zero degree of oriented diamond growth has been proposed in our previous studies. In this study, our molecular orbital PM3 simulation of a step-by-step diamond nucleation further reveals two other metastable diamond/silicon interfacial structures. The orientations of the corresponding diamond grains are parallel to the (001) silicon surface but with in-plane rotations of 20° and 30° respectively with respect to the <110> direction. We relate these two mis-oriented growths to the two satellite peaks of grain orientation distribution. Based on this study, the possibility in experiment to reduce the formation of mis-oriented configurations and to obtain a perfectly oriented diamond growth is discussed.
Simulating Phase Transformations with the Cahn-Hilliard Equation – Potential and Limitations –
Authors: Löchte Lothar , Gottstein Günter 
Published: April 2011

AbstractAn extension of the classical Cahn-Hilliard equation, including elastic interactions is presented. This generalized diffusion equation allows real time simulation of phase-transformations, such as GP-zone formation in a near-commercial ΔICu alloy. No a priori assumptions about kinetics, diffusion fields, as well as precipitate shape are necessary. Shape of precipitates and kinetic of simulated GP-zone formation are in qualitatively good agreement with experiments of Sato and Takahashi, and the concurrenltly derived interfacial energies are reasonable.Two algorithms for a numerical solution of the Cahn-Hilliard equation are presented. While the simple finite difference scheme does not converge, a slightly more complicated Fourier spectral method behaves reasonable as tested for a synthetic chemical potential.
Dense-WDM Components and Systems: A Reliability Overview
Authors: Etemad Shahab 
Published: April 2011

AbstractIn this paper we review field data from failures related to materials and devices that are the building blocks of optically amplified dense-wavelength division multiplexed (DWDM) transmission systems. A DWDM transmission system consists of at least three distinct components: an optical multiplexer, one or more optical fiber amplifiers (OFAs), and an optical demultiplexer. A tandem arrangement of these components performs the function currently up to 40 independent high speed optical communications channels (about 2 million phone calls) over a single fiber link. Of these components, OFAs are considered the workhorse of this new technology, and, as with any new technology, their reliability is the focus of considerable attention. Commercially available OFAs are erbium-doped silica or fluoride fibers that operate in the 1550 nm optical communication window. Such OFAs consist of an active Er-doped fiber and pump laser(s) that collectively are referred to as the gain module, passive optical components used for routing, and electronic components for monitoring and operational support. We present the result of the failure analysis for each part as well as their role in the failure of the OFA. Using the data from systems deployed in the field, we summarize the history of failures of OFAs and other components and discuss their impact on the reliability of the DWDM system as a whole. From a material, packaging and system integration point of view, we address the reliability merits of different designs that, by and large, perform the same overall function. Finally, we shall outline how network providers that deploy such DWDM systems would benefit from a manufacturing strategy that incorporates reliability in its initial steps starting with the materials and packaging needs.
Fracture and Abrasion Resistance Tests for Optical Fiber Coatings
Authors: Wissuchek D. J. , Walter D. J. , Clark D. A. , Glaesemann G. S. 
Published: April 2011

AbstractThe properties of the optical fiber buffer coating play a critical role in the strength and handleability of optical fibers. Tests have been developed to measure a coating's resistance to mechanical damage. Two such tests are described here. The indentation rupture test involves indenting coated fiber with diamond pyramids and measuring the load at which the pyramid punctures the coating. Finite element analysis is used to determine the strain energy absorbed by plastic deformation of the coating. The toughness of the outer coating layer and the toughness of the inner coating/glass interface can be determined from the crack dimensions produced during rupture of the coating. Strength after mechanical abrasion is a procedure wherein a hollow tube of coating is removed from an optical fiber and subsequently bombarded with an abrasive grit. The effects of the abrasion event are measured by a tensile test of the tube. Results for both tests are obtained for two coating systems. The validity of the tests for measuring coating properties is discussed.
Impact Damage and Strength Degradation of Fused Silica
Authors: Ritter J. E. , Jakus K. , Panat R. P. 
Published: April 2011

AbstractFused silica in service can suffer from strength degradation due to a localized contact load or particle impact that can cause cracking about the indentation or impact site. This cracking generally consists of radial, lateral, and cone cracks and is independent of whether the indenter or particle is sharp or blunt or whether the impact is subsonic or hypervelocity. The impact site is generally characterized by a shallow pit surrounded by an array of microcracks. The pit is formed by the fragmentation of the glass due to the intersecting radial, lateral, and cone cracks. With either static indentation or particle impact, it is the radial crack that controls strength degradation. The applicability of indentation fracture mechanics in predicting this strength degradation is discussed.