bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Photovoltage Monitoring of Silicon Surface Native and Chemical Oxides following Wafer Cleaning and Rinsing Operations
Authors: Rosato John J. , Hall R. Mark , Parry Thad B. , Lindquist Paul G. , Jarvis Taura D. 
Published: April 2011

ABSTRACTWe report on the use of the Surface PhotoVoltage (SPV) technique to monitor the Si surface bonding arrangement, and the impurity metallic contamination level prior to critical diffusion processes via the indirect measurement of surface charge and diffusion length, respectively. We show that the effectiveness of the pre-diffusion wet chemical cleaning and rinsing sequences can be accurately monitored via the real-time, nondestructive SPV measurement. In particular the nature of the surface passivation/chemical oxide formed during the cleaning and rinsing operations can be monitored by quantitative surface charge measurements. The importance of the prior wafer history is highlighted, as is the role of the Si starting material and measurement parameters.
Impact of Chemomechanical Polishing on the Chemical Composition and Morphology of the Silicon Surface
Authors: Fusstetrer Hermann , Schnegg Anton , Gräf Dieter , Kirschner Helmut , Brohl Michael , Wagner Peter 
Published: April 2011

ABSTRACTThe polishing technology used for manufacturing ultraflat and smooth Si surfaces on a large scale is the chemomechanical polishing (CMP) technique. This technique combines the chemical corrosive removal of silicon atoms and the mechanical transport of the agents. The removal rates strongly depend on the interaction of mechanical parameters and the chemistry involved in the polishing process like the pH of the alkaline polishing slurry used. Removal of Si during CMP is explained by a nucleophilic attack of OH− to silicon atoms catalyzing the corrosive reaction of H2O resulting in cleavage of silicon backbonds. Characterization of the surface chemistry of the silicon wafer after polishing by X-Ray Photoelectron Spectroscopy and High-Resolution Electron Energy Loss Spectroscopy reveals an oxide free, predominantly hydride covered silicon surface displaying hydrophobic properties. Morphological features like microroughness as well as localized surface irregularities on the silicon surface, also referred to as Light Point Defects, depend on different strongly interacting process parameters. Microroughness is reduced by CMP by several orders of magnitude as characterized by lightscattering techniques and Atomic Force Microscopy.
A New Ion Beam Deposition Technique for Low Temperature Silicon Epitaxy
Authors: Mohajerzadeh S. , Selvakumar C.R. , Brodie D.E. , Robertson M.D. , Corbett J.M. 
Published: April 2011

AbstractWe report the results of an investigation to grow thin Si films on Si substrates at low substrate temperatures using ionized SiH4 gas generated with a Kaufman type ion gun. This investigation shows island-growth at higher substrate temperatures (500-700°C) in the form of square-based pyramids. by lowering the substrate temperature to 300°C, we were able to achieve a planar growth. the growth rate can be enhanced by introducing elemental Si from a thermal evaporation source. Scanning electron microscopy, transmission electron microscopy and electron diffraction analysis were used to study the crystalline quality of the samples prepared at different temperatures.
Preparation and Characterization of Chromium Containing amorphous Hydrogenated Carbon Films (A-C:H/Cr)
Authors: Gampp R. , Gantenbein P. , Oelhafen P. 
Published: April 2011

AbstractChromium containing amorphous hydrogenated carbon films (a-C:H/Cr) were prepared in a process that combines rf plasma activated chemical vapor deposition of methane and magnetron sputtering of a chromium target. During the deposition the silicon substrates were kept at 200°C and dc biased at -200 V in order to obtain films with high chemical stability which is required for the application as solar selective surfaces. the films with different Cr concentrations (5 to 49 at.%) were characterized by in situ x-ray photoelectron spectroscopy (XPS). Up to 40 at.%, chromium proves to be built into the cermet-like films in the form of chromium carbide clusters. above 40 at.%, chromium is partly metallic. a modification of the a-C:H matrix in the vicinity of the chromium carbide clusters has been observed.
Deposition of aluminum Oxynitride Films by Magnetron Sputtering: Effect of Bombardment and Substrate Heating on Structural and Mechanical Properties
Authors: Smilgys Russell V. , Takamura Eric , Singer Irwin L. , Robey Steven W. , Kirkpatrick Douglas A. 
Published: April 2011

ABSTRACTAluminum oxynitride films, 1 μm thick, are deposited onto glass substrates by planar magnetron sputtering from an alumina target in a mixture of nitrogen and argon. one set of films is deposited onto glass substrates that are heat sunk to a holder, whose temperature is held below 100°C. a second set of films is deposited onto glass substrates that are mechanically clamped to a holder, whose temperature is allowed to rise up to 250°C. Characterization by continuous indentation testing, secondary electron microscopy, and x-ray diffraction reveals significant differences in mechanical properties and surface structure between the two sets of films. Films deposited with holder cooling have a smooth surface and no evidence of crystallinity; films deposited without holder cooling have etch pits on their surface that vary with position across the substrate. the later films show crystallinity and have twice the hardness and a 60% greater elastic modulus.
Electron Beam Assisted Chemical Vapor Deposition of Gold in an Environmental Tem
Authors: Kouvetakis John , SharmA Renu , Ramakrisna B. L. , Drucker Jeff , Seidler Paul 
Published: April 2011

AbstractWe demonstrate a novel technique for in situ observation of the chemical vapor deposition of high purity gold using ethyl(trimethylphosphine)gold(I). an environmental transmission electron microscope with 3.8 eV resolution was used to observe and compare the growth of the material with or without electron beam irradiation (120 keV) with Si (100) substrate temperatures ranging from 125-200 °C. Typical precursor pressures of 10-4 Torr and E-beam irradiation resulted in rapid growth of virtually continuous gold films. thermal deposition without the beam resulted in low nucleation densities, low deposition rates, and island-like growth. Images and diffraction patterns acquired during the deposition process indicated polycrystalline gold and elemental analysis at the nanometer scale showed that the films had excellent chemical purity. atomic force microscopy was also used to investigate the three dimensional morphology of the materials. the most notable result of the deposition process is the dramatic enhancement of the growth rate due to the beam irradiation.
Surface Damage During Kev Ion Irradiation: Results of Computer Simulations
Authors: Averback R.S. , Ghaly Mai , Zhu Huilong 
Published: April 2011

AbstractMD simulations have been employed to investigate damage processes near surfaces during keV bombardment of metal targets. For self-ion implantation of au, Cu, and Pt in the range of 5-20 keV, we have found that the proximity of the surface leads to significantly more damage and atomic mixing in comparison to recoil events occurring in the crystal interior. IN some cases, large craters are formed in a micro-explosive event, while in others a convective flow of atoms to the surface creates adatoms and leaves dislocations behind. Both the amount damage created in the surface and its morphology depend sensitively on the details of the energy deposition along individual ion trajectories. the results of these simulations will be summarized and compared to recent scanning tunneling microscopy studies of individual ion impacts in Pt and Ge.
Smoothing During Ion-Assisted Growth by Transient Ion Beam-Induced Defects
Authors: Kellerman B.K. , Chason E. , Floro J.A. , Picraux S.T. , White J.M. 
Published: April 2011

AbstractSeveral studies have shown that the surface morphology can be smoother during simultaneous ion bombardment and growth than during growth alone, however, the atomistic mechanism responsible for the smoothing effect has been difficult to determine. We have developed Monte Carlo simulations of growth and defect diffusion to model the interaction between growth atoms and ion-induced defects and to present a simple atomistic mechanism that describes the effects of low-energy ion bombardment during ion-assisted growth of germanium. Measurements of ion-induced point defect production indicate that a large number of defects exist only temporarily on the surface at typical growth temperatures, because the defects have sufficient mobility to recombine and annihilate. We propose that this ion-induced transient defect population plays a significant role in modifying the dynamic surface morphology. the simulations support a surface smoothing mechanism that involves the destabilization of adatom islands by the transient ion-induced defects. the optimum simulated steady-state surface morphology can be achieved with ion-induced defect production rates less than or equal to 10 defects/ion. We find that low-energy ion bombardment during growth effectively lowers the temperature at which step-flow growth can be achieved.
Observation of the Early Stages of B-Axis Oriented Prba2Cu3O7-x Thin Film Growth by AFM
Authors: Yong Sung Gun , Dae Suh Jeong , Jung Sang-Don 
Published: April 2011

AbstractThe initial stages of the growth of b-axis oriented PrBa2Cu3O7-x (PBCO) films on LaSrGaO4 (100) substrates were investigated by atomic force microscopy to follow the growth of the thin films. Series of films with thickness ranging between 0.34 nm and 100 nm were prepared under identical pulsed laser deposition conditions. No sprial-topped or flat-topped islands were observed and the scale of the surface roughness was lower than that of the c-axis oriented growth mode. the 300 nm-thick in-plane aligned a-axis oriented YBCO films have the root mean square (RMS) surface roughness of 2 nm. It is considered that the b-axis oriented PBCO films on LaSrGaO4 (100) substrates were nucleated and grown by layer-by-layer like growth mode.
Pulsed Laser Deposition of Cadmium Stannate, a Spinel-Type Transparent Conducting Oxide
Authors: Mcgraw Jeanne M. , Parilla Philip A. , Schulz Douglas L. , Alleman Jeffrey , Wu Xuanzhi , Mulligan William P. , Ginley David S. , Coutts Timothy J. 
Published: April 2011

AbstractWe present the first report of the synthesis of Cd2SnO4 films by pulsed laser deposition. Controlling the substrate temperature and the ambient atmosphere allowed for the synthesis of films ranging from amorphous to crystalline with some crystalline films exhibiting strong texture. Highly transparent films with large mobilities were obtained for both the amorphous and crystalline films. Sheet resistances of 15.5 Ω/square and mobilities of up to 44.7 cm2/V.s were observed. Typical carrier concentrations showed the crystalline films to be degenerate with carrier concentrations of 5 х 1020cm-3 while amorphous films had carrier concentrations lower by about half. Band gaps for the films ranged between 3.1-3.8 eV. these films are attractive candidates for TCO applications in thin film photovoltaic devices, flat panel displays, electrochromic windows, and as plasma filters for thermophotovoltaic devices.
XPS Studies of the Interface Properties of Conductive Adhesive/Eutectic Solder
Authors: Koo Y. C. , Jennings M. C. , Davidson R. D. , McIntyre N. S. 
Published: April 2011

ABSTRACTThe continuing shrinkage of feature size and environmental concerns regarding the use of lead containing solder are major driving forces in the search for alternative technologies for metal interconnects in electronic packaging. Electrically conductive adhesives are considered a potential substitute for the lead-tin solder. This study concentrated on interfacial properties of eutectic solder and silver-filled epoxy adhesives. A freeze fracture technique was employed in order to preserve interfacial information. The chemical composition of the fractured faces varied; the adhesive side was rich in tin, whereas the eutectic solder side showed lead-rich characteristics.
Adhesion of Screen Printed Conductors on Laser Reduced AlN
Authors: Gopalakrishnan S. , Lumpp Janet K. 
Published: April 2011

ABSTRACTAluminum Nitride (AlN) has not attained the type of success alumina has had with thick film materials. This project is aimed at increasing the number of thick film inks compatible with AIN. Excimer laser reduced AIN is metallic, but not sufficiently conductive to act as an interconnection for microelectronic circuits. The reduced surface acts as a bonding layer to promote adhesion of screen printed metal films.Design of Experiments (DOE) plays a critical role in determining the success of a research project. Completely Randomized Nested Classification design strategy is used in these experiments. The Ag-Pd ink formulated for alumina is screen printed on AIN and alumina substrates in a random order and fired. Wires are soldered to the pads and a pull test is done. Analysis of Variance (ANOVA) is used to compare the adhesion strength of Ag-Pd ink formulated for alumina screen printed on Al2O3 and laser reduced AIN substrates.
Chemical Interactions of Au and Ag Conductors in Ceramic Based Electronic Packages
Authors: Vajo John J. , Momoda Leslie A. , Harshbarger Richard W. , Elwell Dennis F. 
Published: April 2011

ABSTRACTIn electronic packages consisting of glass-alumina composite dielectric layers and thick film conductors, Au and Ag conductors on separate layers may alloy. Alloys are formed by Ag+ ion diffusion through the intervening dielectric. The extent of alloy formation is dependent upon whether the Au and Ag conductors are electrically isolated or connected. When the Au and Ag conductors are electrically isolated, alloying is self-limiting and occurs by reduction of Ag+ ions and dissolution of the metallic Ag into the Au. In this case, the reduction of Ag+ is accompanied by oxidation of the lattice oxygen anions forming O2 gas which accumulates to form blisters. If the Au and Ag conductors are electrically connected, then the alloying is not self-limiting and occurs without the formation of O2. In this study, we quantitatively characterize the alloying reactions which occur during firing and propose mechanisms for specific dielectric and conductor packages. The presence of these alloying reactions can affect the reliability and the performance of the electronic ceramic package.
Advances in Liquid Encapsulated Chip-on-Board / MCM-L Technology
Authors: Robinson Dale L. , Clegg David B. 
Published: April 2011

ABSTRACTChip-on-Board technology (COB), or the currently more often used MCM-L acronym (MultiChip Module - Laminate), has long been touted as the low cost, high density electronics packaging choice of the future. Unfortunately, poor reliability performance in comparison to traditional plastic packaging, has been a trademark of COB/MCM-L. Recent advances in processes and materials for COB/MCM-L are providing a paradigm shift in reliability, and providing cost effective high reliability packaging solutions for COB/MCM-L. This paper examines the history of recent advances in liquid encapsulated COB/MCM-L and provides guidelines for selecting appropriate materials and processes for their successful implementation into cost effective manufacturing.
Mold Compounds: Linking Material Science and IC Package Reliability
Authors: Groothuis Steven K. , Heinen K. Gail 
Published: April 2011

ABSTRACTMaking the transition from mechanical testing of mold compounds to actual Integrated Circuit (IC) plastic package reliability requires an understanding of material behavior under the influences of moisture, temperature, and varying load conditions. This paper will focus on the role of material strengths, strain energy, and nonlinear effects in determining plastic package reliability. Examples of correlation between materials testing and reliability data will be presented.
Thin Film Epitaxial Oxide Optical Waveguides
Authors: Fork D. K. , Armani-Leplingard F. , Kingston J. J. , Anderson G. B. 
Published: April 2011

AbstractOne of the most challenging applications of ferroelectric thin films is the formation of technologically practical optical waveguideing devices, particularly in the context of a dynamically changing environment where competing light sources and optical materials simultaneously undergo rapid improvement. In order to assess the prospects of this technology, a fundamental understanding of waveguide loss is being pieced together. This includes the relative contributions of surface scattering, and grain boundary scattering to optical losses. With computational models, it is possible to predict the surface losses from measured topographic data. This tool provides a method to probe the residual effects of grain boundaries, defects and impurities on optical losses. A comparative anatomy of various thin film structures and their loss characteristics will be provided in the context of these experiments.
Evaluation of Hylan B (Hylan Gel) as Soft Tissue Dermal Implants
Authors: Larsen N.E. , Leshchiner E. , Pollak C.T. , Balazs E.A. 
Published: April 2011

AbstractHylan B gel is a viscoelastic insoluble crosslinked derivative of the natural hyaluronan (hyaluronic acid, HA) polymer. Hyaluronan derivatives such as hylan B have enhanced rheological properties and possess the desired biological properties of natural hyaluronan. Hylan B was evaluated in nonclinical in vivo studies for biocompatibility and residence times in dermal tissues. In one study, residence time of radiolabeled [14C]-hylan B was evaluated in guinea pigs following intradermal administration with serial sacrifice (0, 1, 4, 12, 24 weeks). Analysis of radioactivity revealed that at 6 months post-implantation up to 98% of the radioactivity was recovered from the specific injection site (mean 76.7± 29.4%). A half-life time of 12.2 months was estimated from analysis of the data. In another study, the behavior of hylan B gel implanted in the intradermal and subcutaneous tissue of guinea pigs was evaluated at 3 days and at 1, 2, 4, 9, 13, 26 and 52 weeks. In this study, collagen implants were evaluated in parallel with hylan B gel implants in the same animals. Hylan B gel was found to be biologically compatible and stable in the dermal tissue. At one year post-implantation, hylan B gel was detected in a majority (12/16) of test sites. None of the collagen implant materials was detected at one year post-implantation.
Dacron-Urethane Composite for Reconstructive Surgery
Authors: Leake Donald 
Published: April 2011

AbstractA composite biocompatible material made of polyethyleneterephalate (Dacron) and polyetherurethane was fabricated as an aid to bone grafting for the reconstruction of large bony defects of the craniomaxillofacial regions. Bone graft material is placed within the confines of the Dacron-urethane implant and new bone forms to the shape imposed by the implant.The principle application of this material has been for the reconstruction of defects of the neurocranium and of the mandible [1–5]. A number of other applications have been studied including reconstruction of long bone discontinuity defects [6], reconstruction of an infant's anterior chest wall [19], the prosthetic replacement of large defects of the cervical trachea [7] and as a potential material for a thrombo-resistant small diameter vascular prosthesis [8].
Degradation of Poly(Anhydride-Co-Imides): Novel Polymers for Orthopedic Applications
Authors: Uhrich Kathryn E. , Ibim Sobrasua E. M. , Laurencin Cato T. , Langer Robert 
Published: April 2011

AbstractNovel polymers with good mechanical properties are being developed as degradable matrices for bone growth and regeneration. The poly(anhydride-co-imides) were synthesized from trimellitylimidoglycine and 1,6-bis(p-carboxyphenoxy)hexane in molar compositions of 10:90, 30:70 and 50:50. These polymers have compressive strengths (23–57 MPa), which are similar to human cortical bone. 1 In vitro degradation was performed under acidic (pH 5), physiological (pH 7.4), and basic (pH 10) conditions. The degradation rate increased under basic conditions and by increasing the amount of trimellitylimidoglycine in the polymer backbone. Two erosion zones were observed in the polymers by microscopy. In vivo polymer degradation was evaluated by characterizing polymer discs implanted in subcutaneous tissue of rats over a 56 day time period. Copolymers with the highest ratio of trimellitylimidoglycine in the polymer backbone were completely degraded by 56 days, the other compositions remained in the tissue as solid pellets at this time. In vivo degradation was much slower than the corresponding in vitro degradation.
Poly(L-Lactic Acid-Co-Aspartic Acid): Interactive Polymers for Tissue Engineering
Authors: Hrkach Jeffrey S. , Ou Jean , Lotan Noah , Langer Robert 
Published: April 2011

AbstractOne of the challenges in the field of tissue engineering is the development of optimal materials for use as scaffolds to support cell growth and tissue development. For this purpose, we are developing synthetic, biodegradable polymers with functional sites that provide the opportunity to covalently attach biologically active molecules to the polymers, so they can predictably interact with cells in a favorable manner to enhance cell attachment and growth. The preparation of poly(L-lactic acid-co-aspartic acid) comb-like graft copolymers from poly(L-lactic acid-co-β-benzyl-L-aspartate), and the casting of polymer films by solvent evaporation were carried out.
Parasitic Reactions between Alkyls and Ammonia in OMVPE
Authors: Chen C.H , Liu H. , Steigerwald D. , Imler W. , Kuo C.P. , Craford M.G 
Published: April 2011

ABSTRACTThe parasitic reactions between ammonia and commonly used alkyls have been studied in a horizontal OMVPE reactor. The results indicate that parasitic reactions between TMA1 and NH3 is severe, leading to the necessity to grow A1N at low reactor pressure. On the other hand, parasitic reactions between TMGa+NH3 and TMIn+NH3 are not significant and it is possible to grow GaN and GaInN at any reactor pressure.
Growth of InGaN Films by MBE at the Growth Temperature of GaN
Authors: Singh R. , Moustakas T.D. 
Published: April 2011

ABSTRACTWe report the growth of InGaN alloys over practically the entire composition range at the growth temperature of GaN (700–800 °C) by MBE. We found that when the grown films are thick (> 0.3 μm), incorporation of more than about 30% indium results in phase separation of InN, which is consistent with spinodal decomposition. On the other hand we discovered that such phase separation is absent in thin InGaN films ( < 600Å) grown as GaN/InGaN/GaN heterostructures. In such configurations we were able to incorporate up to 81% In, which is the highest yet reported.
Effect of Carrier Gas on the Surface Morphology and Mosaic Dispersion for GaN Films by Low-Pressure MOCVD
Authors: Kistenmacher T. J. , Wickenden D. K. , Hawley M. E. , Leavitt R. P. 
Published: April 2011

ABSTRACTLow-pressure metal-organic chemical vapor deposition (MOCVD) has been used to deposit unnucleated and self-nucleated GaN thin films on (00.1) sapphire substrates. For the self-nucleated films, initial layers were grown at 540°C using trimethylgallium and ammonia as elemental sources and either nitrogen or hydrogen as the carrier gas. Using these same gas phase conditions, overlayers on native (00.1) sapphire substrates or the GaN-nucleated (00.1) sapphire substrates were deposited at 1025°C. The surface morphology and mosaic dispersion of these unnucleated and self-nucleated GaN thin films have been surveyed by a combination of real space images from atomic force microscopy and reciprocal space intensity data from X-ray scattering measurements. As expected, the unnucleated GaN films show a large-grained hexagonal relief, typical of three-dimensional island growth. However, the self-nucleated films are shown to be dense mosaics of highly oriented islands, emblematic of a more two-dimensional growth.