bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parenting as a “package deal”: Relationships, fertility, and nonresident father involvement among unmarried parents
Authors: Tach Laura , Mincy Ronald , Edin Kathryn 
Published: February 2010

Abstract
Fatherhood has traditionally been viewed as part of a “package deal” in which a father’s relationship with his child is contingent on his relationship with the mother. We evaluate the accuracy of this hypothesis in light of the high rates of multiple-partner fertility among unmarried parents using the Fragile Families and Child Wellbeing Study, a recent longitudinal survey ofnonmarital births in large cities. We examine whether unmarried mothers’ and fathers’ subsequent relationship and parenting transitions are associated with declines in fathers ’ contact with their nonresident biological children. We find that father involvement drops sharply after relationships between unmarried parents end. Mothers’ transitions into new romantic partnerships and new parenting roles are associated with larger declines in involvement than fathers’ transitions. Declines in fathers’ involvement following a mother’s relationship or parenting transition are largest when children are young. We discuss the implications of our results for the well-being ofnonmarital children and the quality of nonmarital relationships faced with high levels of relationship instability and multiple-partner fertiliy.
Bioproducts Process Pathways for Kraft Paper Mills
Authors: Dickerson Catherine M. , Rubin Jonathan 
Published: March 2010

Abstract
Energy use in the United States is heavily reliant on imported fossil fuels. Finding a way to produce renewable fuels that can replace these fossil fuels will address national security threats, sustainability concerns inherent in the use of fossil fuels, and keep manufacturing in rural areas. An important alternative fuel for the near term is ethanol, and producing it from a cellulosic feedstock allows the fuel source to remain independent of the food chain. A solid body of research has made it clear that a brand-new stand-alone biorefinery using biomass is not cost-effective under current business conditions. In light of this, we have looked at the economic viability of a co-located facility, specifically Kraft pulp mills in the State of Maine. We have looked at the opportunity to utilize the “near-neutral” extraction process developed at the University of Maine, whereby Kraft pulp mills can begin to meet the demand for alternative fuels. By incorporating the near-neutral extraction process within the pulping process, ethanol and acetic acid can be produced as “first stage” products while still producing pulp, thereby expanding the product line of the pulp mill while addressing the need for finding alternative to petroleum feedstocks. This paper discusses both the near-neutral extraction process and a thermochemical process that can be utilized in a Kraft pulp mill based biorefinery to produce ethanol and acetic acid as initial products. We analyze potential investment and production costs for a biorefinery based on studies that have looked specifically at this type of evolution, as well as cellulosic biorefineries that are based on other types of processes. We also identify potential “second stage” fuels that could be produced, as well as the modes of transportation that can be used to get the fuels and products to the existing infrastructure.
Structural Defects in GaN-based Materials and Their Relation to GaN-based Laser Diodes
Authors: Tomiya Shigetaka , Ikeda Masao , Tanaka Shinji , Kanitani Yuya , Ohkubo Tadakatsu , Hono Kazuhiro 
Published: February 2010

AbstractReduction of structural defects in III-nitride based optical devices is of critical importance for high efficient and high reliable optoelectronic performance. Here, three different types of structural defects such as threading dislocations, Mg-related pyramidal defects and columnar defects, observed in GaN-related epitaxial films are described and their relation to reliability of GaN-based LDs is discussed. Composition fluctuations of GaInN MQWs with different In concentrations by analyzed by a laser assisted 3D atom probe are also described.
Mechanism of Defect Reactions in Semiconductors
Authors: Shinozuka Yuzo 
Published: February 2010

AbstractProposed mechanisms so far on defect reactions in semiconductors are reexamined. Structural instability of point defects is explained in terms of the Jahn-Teller effect. It is found that the tetrahedral coordinated bonds, which do not have inversion symmetry, are not so rigid as we consider, especially for hole localization. Second topic is the phonon-kick mechanism for defect reactions under carrier injection. In order to discuss this mechanism in detail, we recall the configuration coordinate (c-c) diagram, which is often misunderstood in the literature. The proper relation is explained among the lattice distortion, the position of the electronic level in the band gap (thermal and optical depths), the total energy the multiphonon (e and h) carrier capture processes and the following induced lattice relaxation. A numerical simulation has been performed on phonon kick mechanism. It is found that a rapid increase of the transient lattice vibration around the defect is possible and the probability critically depends on the carrier concentrations and the phonon frequency distribution.
Reliability and Performance of Pseudomorphic Ultraviolet Light Emitting Diodes on Bulk Aluminum Nitride Substrates
Authors: Grandusky James , Cui Yongjie , Mendrick Mark C. , Gibb Shawn R. , Schowalter Leo 
Published: February 2010

AbstractReliability and performance of ultraviolet light emitting diodes have suffered due to the high dislocation density of the AlN and high Al-content AlxGa1-xN layers when grown on foreign substrates such as sapphire. The development of pseudomorphic layers on low dislocation density AlN substrates is leading to improvements in reliability and performance of devices operating in the ultraviolet-C (UVC) range. One major improvement is the ability to operate devices at much higher current densities and input powers than devices on sapphire substrates. This is due to the better thermal properties and lower dislocation density of devices on AlN substrates. Devices with active area of 0.001 cm2emitting at ∼265 nm have been measured for their reliability and change in power output over time at input currents of 20 mA (20 A/cm2), 100 mA (100A/cm2) and 150 mA (150 A/cm2). When operating at currents of 20 mA over 3500 hours of consecutive operation has been demonstrated with typical decay of ∼27% over the 3500 hours. Extrapolating the decay with a linear fit gives a L50 (time to 50% of initial power) of ∼5000 hrs. However it is desirable to be able to model the decay to better understand the kinetics and better understand the mechanisms. In order to do this, the lifetime at 20 mA and 100 mA were modeled using an exponential decay function, square root transformation and a log transformation to both be able to fit the experimental data and predict future performance.
Dependency of Indium Concentration on Structural Defects in MOVPE-grown InGaN/GaN Heterostructures
Authors: Dudding J S , C Wenyu , Korakakis D 
Published: February 2010

AbstractIndium Gallium Nitride (InxGa1-xN) alloys are currently playing an ever increasing role in optoelectronic devices as the bandgap of such alloys can theoretically be tuned between 0.7eV and 3.4eV–covering the entire visible spectrum. Although growth of high quality InxGa1-xN alloys with high indium mole fractions are difficult or presently unattainable, InGaN alloys are still a viable choice for light emitters and detectors over the visible (blue/green) to ultraviolet spectrum. However, many inherent problems during InGaN growth via Metal Organic Vapor Phase Epitaxy (MOVPE) arise due to the large lattice mismatch and low miscibility between GaN and InN–leading to the formation of Inverted Hexagonal Pyramid (IHP) defects at the termination of threading dislocations. Additionally, growth of InGaN at lower temperatures to promote increased indium incorporation results in poor surface morphology. Several methods such as strained layer superlattices and low mole fraction InGaN layers before the growth of the InGaN/GaN MQW structures have been shown to relive strain in the MQWs, thus reducing the density of IHP defects and/or improving the optical output characteristics. This work focuses on the application of GaN monolayer insertions during InGaN quantum well growth via Metal Organic Vapor Phase Epitaxy (MOVPE) as a means to reduce the IHP defect density and passivate effects on surface roughness while observing variations in indium concentration. Observations include the reduction of IHP defect density by nearly twofold as the number of GaN monolayer interruptions increase from zero to three while sustaining only slightly lower effective indium concentrations.
Sub Surface Material Characterization using High Frequency Eddy Current Spectroscopy
Authors: Heuer Henning , Hillmann Susanne , Klein Marcus , Meyendorf Norbert 
Published: February 2010

AbstractBy launching new processes introduced by nano science into much more conventional industrial applications fast, robust and economical reasonable inspection methods are required for process control and quality assurance. Coming from high tech industries e.g. semiconductor industries the methods available for thin film characterization and quality control are complex and often require scientific skilled personal. High frequency eddy current spectroscopy in reflection or transmission configuration allows a contactless measurement of e.g. copper thin films on silicon with a thickness resolution better that 5 nm. Due to the insensitivity of the transmission mode to dislocations or slight tilting of the sample the high frequency eddy current method is a practicable method for thin film characterization under industrial environment.
Surfactant Effects of Indium on the Growth of AlN/GaN Distributed Bragg Reflectors via Metal Organic Vapor Phase Epitaxy
Authors: Rodak L E , Miller Christopher M , Korakakis D 
Published: February 2010

AbstractDistributed Bragg Reflectors (DBRs) remain critical to the fabrication of various nitride based optoelectronic devices. In particular, DBRs are often employed for cavity formation in Resonant Cavity Light Emitting Diodes (RCLEDs) to enhance and obtain a more directional emission and also in Vertical Cavity Surface Emitting Lasers (VCSELs). As a result, epitaxially grown reflectors are attractive for direct integration in the device, reduced processing requirements, and the formation of narrow cavities. In the III-Nitride material system, Aluminum Nitride (AlN) and Gallium Nitride (GaN) offer a large contrast in refractive index and are therefore well suited for fabricating DBRs with high reflectivity and wide bandwidths using relatively few periods. However, material cracking arising from to the 2.4% lattice mismatch and difference in thermal expansion coefficient decreases reflectivity and is detrimental to the efficiency of subsequent device fabrication. Several techniques, such as superlattice insertion layers or the growth of AlxIn1-xN layers, have been employed to reduce strain and cracking in such structures. In this work, results of the use of indium as a surfactant in the Metal Organic Vapor Phase Epitaxy (MOVPE) of AlN/GaN DBRs will be discussed. Specifically, this study targets AlN/GaN DBRs with peak reflectivity at ranging from 465 nm to 540 nm. Indium has been used as a surfactant during growth by introducing trimethylindium into the system. It has been shown that crack formation is dependent on the flow of the indium precursor despite minimal indium incorporation into the lattice. Image processing techniques were used to quantify the crack length per square millimeter and it was observed that indium has a significant effect on the crack formation and can be used to reduce the total crack length in these structures by a factor of two.
Distribution of Hydrogen- and Vacancy-Related Donor and Acceptor States in Helium-Implanted and Plasma-Hydrogenated Float-Zone Silicon
Authors: Job Reinhart , Niedernostheide Franz-Josef , Schulze Hans-Joachim , Schulze Holger 
Published: February 2010

AbstractThe formation and evolution of hydrogen- and vacancy-related donor and acceptor states were studied in helium-implanted and subsequently hydrogen plasma-treated n-type Float-Zone (FZ) silicon wafers by means of two-point-probe Spreading Resistance (SR) measurements. He+-implantation was executed at 3.75 MeV and 11 MeV at fluences of 1×1014 cm−2. Post-implantation 13.56-MHz RF-plasma hydrogenations were carried out at 150 W either for 15 min or 1 hour, applying substrate temperatures between 350 °C and 500 °C. Enhanced donor concentrations as well as acceptor-like states were observed in the subsurface layers of the treated FZ Si samples after 15-min post-implantation H-plasma exposures. Under appropriate process conditions, the latter ones compensated for the n-type doping, so that even buried p-type layers were created. The experimental results indicated that oxygen played a central role in the formation of the acceptor-like states.
Low Temperature Copper Deposition by PE-ALD
Authors: Mao Jiajun , Eisenbraun Eric , Omarjee Vincent , Lanslot Clement , Dussarrat Christian 
Published: February 2010

AbstractWith the continuing scaling in device sizes, sputtered copper is not expected to achieve the conformality and surface coverage requirements to be an effective seed layer for electrochemical deposition in sub-32nm features. Additionally, the metallization demands of high aspect ratio TSVs in 3D-architectures pose similar challenges. In this work, a manufacturable low temperature Cu PE-ALD process has been developed employing a novel O and F-free precursor. The ALD process conditions are correlated with key film properties, including deposition rate, composition, step coverage, and resistivity. Additionally, the influence of precursor substituents on the deposition rate and preliminary integration performance are discussed.
Low Frequency Noise Correlation between Electrical and Optical Signals for Predicting Degradation in Organic Light Emitting Diodes
Authors: Chua Soo Jin , Huang Sha , Ke Lin 
Published: February 2010

AbstractThe Low Frequency Noise (LFN) characteristics of Organic Light Emitting Diodes (OLEDs) were investigated in relation to device degradation. The standard layer structure of indium tin oxide (anode), hole transport layer, Alq3, Lithium Fluoride and Aluminium (cathode) was used. With duration of operation, the device degradation is characterized by an eventual drop in the luminance level and the electroluminescence efficiency. Additionally, the driving voltage at a fixed current and the LFN increase gradually during device degradation, accompanied with the formation of non-emissive areas (dark spots). It is found that the coefficient of correlation between voltage fluctuations across the device and low frequency fluctuations of the optical signals remains constant for an initial period and then decreases exponentially with duration of operation and is a sensitive parameter to predict OLED device lifetime. For a number of OLEDs driven at constant current, the device with higher initial correlation coefficient possesses a longer lifetime. The direct relation between LFN correlation and device lifetime can be explained by carrier recombination mechanisms at the microscopic level. An increase in trap density can reduce the internal radiative recombination rate which at the macroscopic level is reflected by a decrease in the correlation coefficient.
Synthesis and Characterization of Tb-doped AlBNO Films for Electroluminescence Devices
Authors: Masumoto Keiko , Iwano Yuta , Kimura Chiharu , Aoki Hidemitsu , Sugino Takashi 
Published: February 2010

AbstractTb-doped AlBNO (AlBNO:Tb) films with various composition ratios are investigated for luminescence layers of inorganic electroluminescence(EL) devices. Luminescence layers with a wide bandgap and a low dielectric constant are required to realize high performance of EL devices. The ultraviolet-visible radiation absorption measurement and capacitance-voltage (C-V) measurement show that the AlBNO:Tb films have wider bandgap and lower dielectric constant than ZnS which is put to practical use as the host material of the luminescence layer. Photoluminescence (PL) measurement indicates that PL intensity increases with increasing B composition ratio in the range of 5 % - 10 %. Moreover, the suppression factor of the PL intensity can be understood through the annealing experiment. The PL intensity of the film with 800 °C annealing is about 10 times larger than that of the film without annealing. X-ray photoelectron spectroscopy (XPS) measurement suggests that Tb4+ ions decrease compared with Tb3+ ions after annealing treatment. O atoms in the AlBNO:Tb film are dissociated from Tb and bonded to B atoms by annealing treatment. This suggests that decrease of Tb4+ ions is related to increase of the PL intensity.
Pre-applied Inter Chip Fill Material and Process for Advanced 3D Chip Stack
Authors: Horibe Akihiro , Yamada Fumiaki 
Published: February 2010

AbstractTo pursue further performance improvement of semiconductor devices, threedimensional (3D) chip integration with TSV would be one of the key technologies in the next decade. Inter Chip Fill (ICF) is a resin to fill gaps between chips, and it would be an important component for highly reliable and durable 3D integrated devices. High performance 3D devices require fine pitch interconnections with small bumps for high pin count with high bandwidth. Smaller bumps lead to narrow gap design between stacked chips inevitably, and the narrow gap is expected to reduce heat resistance and thermo-mechanical stress. However it makes resin filling and flux cleaning processes harder. A preapplied ICF process is one of the potential methods to fill the narrow gaps with a resin. The material is halfcured resin applied on a wafer by spin-coating or film-lamination before chip integration. Flux cleaning process can be eliminated by adding fluxing function in the resin components. Major concerns of multiple chip 3D stacking process are repeated high temperature cycles of metal-joining, and long process time as a result. We are proposing “Stack Joining process” that enables 3D multi chip joining at one time instead of sequential chip by chip joining. In this process, multiple chips are aligned and temporarily stacked sequentially using adhesivity which the ICF has between Tg and initiation temperature of polymerization, and finally all metal bumps of stacked chips are melted and joined altogether. This process can substantially reduces repeated high temperature cycles and process time. As a result this technique could mitigate degradation of device materials.We successfully stacked chips by using the pre-applied ICF which was designed for advanced 3D chip stack having full area array and narrow gap (less than 10um) connections. In this paper, we explain the Stack Joining process flow and conditions. We also discuss the cause of mechanical stress within the stacked chip and required material features of the pre-applied ICF and device structure to reduce the stress.
Determination of Defects Concentration from C-V and G-V Curves in a MOSFET Structure
Authors: Abboud Nadine , Habchi Roland 
Published: February 2010

AbstractThe gate oxides of Si based MOSFET devices are subjected to a high field in order to induce defects in the oxide bulk and at the Si/SiO2 interface. The defects are characterized by a series of gate to source capacitance and conductance measurements. Shifts in the flat band voltage and the threshold voltage are observed and are related to the position of charged defects. The difference of the equivalent charge between the two types of defects is also determined. Conductance measurements are performed to determine the difference of interface states concentration as a function of the high field exposure time.
Uniaxial magnetic anisotropy induced by vicinal surfaces in half metallic La0.7Sr0.3MnO3 thin films
Authors: Perna Paolo , Jiménez Erika , Terán Francisco J. , Méchin Laurence , Camarero Julio , Miranda Rodolfo 
Published: February 2010

AbstractWe present a detailed study of the angular dependence of the magnetization reversal at room temperature of well characterized epitaxial La0.7Sr0.3MnO3 (001) thin films grown onto SrTiO3 (001) vicinal substrates. The step edges at the substrate surface promote a topological modulation of the films along the step direction, breaking the four-fold magneto crystalline symmetry and favoring a two-fold magnetic anisotropy term. The competition between the biaxial and uniaxial anisotropy is depicted within the framework of the current theory, resulting in a vanishing biaxial contribution. The films hence show the magnetization easy (hard) direction parallel (perpendicular) to the steps direction. The thickness-dependent of both anisotropy and magnetization reversal are discussed in terms of topographic changes.
Switching characteristics and magnetoresistance of Co-based multilayered perpendicular magnetic tunnel junctions
Authors: Tadisina Zeenath Reddy , Natarajarathinam Anusha , Gupta Subhadra 
Published: February 2010

AbstractPerpendicularly magnetized magnetic tunnel junctions (pMTJ) using Co based multilayers as free and reference layers have been optimized for perpendicular magnetic anisotropy (PMA) and high tunneling magnetoresistance (TMR). The effect of seed layers, Co thickness and Co/Ni thickness ratio on the anisotropy of these multilayer films has been studied. Intermixing of these multilayers was analyzed by local electrode atom probe (LEAP). The effect of Co thickness, Pd thickness and number of Co/Pd bilayers on the anisotropy and coercivity of the [Co/Pd]n multilayer films have been studied for both free and reference layers. The magnetic behavior of these PMA systems was studied by alternating gradient magnetometer. CoFeB/MgO/CoFeB trilayers sandwiched between the PMA multilayer material systems were studied. The transport properties of the patterned MTJ stacks were measured by PPMS from 10K to 400 K. A maximum TMR of 10% at 10K (5-10% at 300 K) was obtained for these perpendicular MTJ’s (pMTJ), regardless of whether they were magnetically annealed for MgO-CoFeB crystallization or not, indicating that the fcc-bcc-fcc transitions from the fcc multilayers to the bcc CoFeB/MgO/CoFeB do not promote the “giant MgO TMR effect” caused by symmetry filtering.
Single Molecular Magnet - Gold Nanoparticle Composites
Authors: Balaji Gopalan , Bovenkamp Gudrun , Palshin Vadim , Kumar Challa 
Published: February 2010

AbstractThe past decade has witnessed a great interest in single molecule magnets (SMM) especially those based on manganese such as Mn12-acetate due to their potential applications in ultrahigh density data storage and quantum computing devices. The focus so far has been in finding different derivatives of Mn or other complexes based on transition elements in order to raise the blocking temperature of single-molecule magnets (SMMs). Herein we propose a fundamentally new approach of generating new category of SMMs through formation of composite structures by binding SMMs on to nanoparticles. In this report, we present the synthesis and characterization of single molecular magnet - gold nanoparticle composite- Mn12-cysteinate functionalized gold nanoparticles.