bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal Stability and Substitutional Carbon Incorporation far above Solid-Solubility in Si1-xCx and Si1-x-yGexCy Layers Grown by Chemical Vapor Deposition using Disilane
Authors: Carroll M. S. , Sturm J. C. 
Published: June 2019

AbstractGrowth conditions for epitaxy of Si1-x-yGexCx and Si1-xCx alloy layers on (100) silicon substrates by rapid thermal chemical vapor deposition (RTCVD) with disilane as the silicon source gas are described and the Si1-xCx conditions are compared to previously reported RTCVD growth conditions for epitaxy of Si1-xCx using silane as the source gas. The thermal stability of the layers at 850°C in nitrogen is examined using x-ray diffraction as a measure of the average substitutional carbon concentration in the layers after annealing. A characteristic time constant to describe the reduction of average substitutional carbon concentration in the layer is extracted from the XRD measurements. The characteristic time constants are found to agree within a factor of 3 with that observed in previous reports. However, the time constants are found to depend more strongly on the as-grown substitutional carbon concentration than what is predicted by simple precipitation kinetics, assuming carbon diffusion to a constant number of nucleation centers.
Non-routine Dopant, Impurity and Stoichiometry Characterization of SiGe, SiON and Ultra-low Energy B-implanted Si Using Secondary Ion Mass Spectrometry
Authors: Magee Charles W. , Buyuklimanli Temel H. , Marino John W. , Novak Steven W. , Sahiner M. Alper 
Published: June 2019

AbstractNew, non-routine metrology issues are addressed for three kinds of materials and processes that are necessary for the fabrication of ultra-high speed devices. We look at the problems and solutions for measuring both stoichiometry and dopant content of SiGe material when using Cs primary ion bombardment. We examine the challenges of determining the N content of ultra-thin SiON gate dielectrics with emphasis on what will be necessary for the measurement of 1nm thick oxides. And finally we show some promising early results of using a new protocol for measuring ULE B ion implant profiles in the top 3nm with emphasis on obtaining a more realist profile shape in this region for TCAD modeling purposes.
Calibration of Phosphorus Implantation Dose in Silicon by Radiochemical Neutron Activation Analysis
Authors: Paul Rick L. , Simons David S. 
Published: June 2019

AbstractA radiochemical neutron activation analysis (RNAA) procedure has been developed, critically evaluated, and shown to have the necessary sensitivity, chemical specificity, and matrix independence to certify phosphorus at ion implantation levels. 32P, produced by neutron capture of 31P, is chemically separated from the sample matrix, and measured using a beta proportional counter. Analysis of 12 pieces of a silicon wafer, implanted at a nominal dose of 8.5 x 1014 atoms·cm-2, yielded a phosphorus concentration of (8.30 ± 0.16) x 1014 atoms·cm-2 (expanded uncertainty), in agreement with a consensus value of (8.23 ± 0.33) x 1014 atoms·cm-2 (1s uncertainty) determined from a round robin SIMS investigation. The relative standard deviation of < 2 % is suitable for certification of a Standard Reference Material.
Microstructural and Electrical Characterization of Barium Strontium Titanatebased Solid Solution Thin Films Deposited on Ceramic Substrates by Pulsed Laser Deposition
Authors: Fountzoulas Costas G. , Potrepka Daniel M. , Tidrow Steven C. 
Published: June 2019

AbstractFerroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba0.6Sr0.4Ti1-y(A 3+, B5+)yO3 thin films, of nominal thickness of 0.65 μm, were synthesized initially at substrate temperatures of 400°C, and subsequently annealed to 750°C, on LaAlO3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the postannealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>Tc) regime.
Electrically Tunable Phase Shifters With Air-Dielectric Sandwich Structure
Authors: Jeong Minki , Kazmirenko Victor , Poplavko Yuriy , Kim Beomjin , Baik Sunggi 
Published: June 2019

AbstractElectrically tunable microwave phase shifter was developed by inserting dielectric slab and piezoelectric actuator inside a waveguide. Air-dielectric sandwich structure of dielectric material and thin air gap was placed inside a waveguide, where the thickness of air gap is controlled by the actuator. Small changes in the ratio between the thickness of dielectric material and air gap induce significant changes in the effective dielectric constant of the air-dielectric sandwich structure. Phase shifts of 20∼200 degrees were realized with the dielectric materials such as (Mg, Ca)TiO3 while the thickness of air gap is changed between 0 to 30 μm by piezoelectric control. Since the dielectric ceramics has very small loss (tand ∼ 10-4) and the air gap has practically no loss, the total structure shows low insertion loss.
Deposition of Polycrystalline ZnO Films by Two-Step Method and Characterization of Thermal Annealing Effects
Authors: Lee Jin-Bock , Lee Myung-Ho , Lee Hye-Jung , Park Jin-Seok 
Published: June 2019

AbstractPolycrystalline ZnO thin films were deposited on SiO2/Si(100) substrate using RF magnetron sputtering. The film deposition performed in this work was composed of following two procedures; the 1st-deposition for 30 min without oxygen at 100 W and the 2nd-deposition with oxygen in the range O2/(Ar+O2) = 10∼50 %. Deposited ZnO films revealed a strongly c-axis preferred-orientation (the corresponding texture coefficient ∼ 100 %) as well as a high resistivity (> 107 Ωcm). It was also observed that the crystallite size of ZnO was noticeably increased by thermal-annealing.
On the GHz Frequency Response in Nanocrystalline FeXN Ultra-Soft Magnetic Films
Authors: Chechenin N.G. , Craus C.B. , Chezan A.R. , Vystavel T. , Boerma D.O. , Hosson J.Th. M. De , Niesen L. 
Published: June 2019

AbstractThe periodicity and angular spread of the in-plane magnetization for ultrasoft nanocrystalline FeZrN films were estimated from an analysis of the ripple structure, observed in Lorentz transmission electron microscopy (LTEM) images. The influence of the micromagnetic ripple on the ferromagnetic resonance (FMR) width is analyzed using an approach based on the Landau-Lifshitz equation. A strong dependence of the resonance width on the magnetic moment dispersion is predicted. To a large extent this particular aspect explains the high frequency response in some of our films.
Microwave Dielectric Spectroscopy of Ferroelectric Thin Films
Authors: Kim Beomjin , Kazmirenko Victor , Jeong Minki , Poplavko Yuri , Baik Sunggi 
Published: June 2019

AbstractWe devised a measurement method of microwave dielectric constants of dielectric thin films without applying electrodes. The method uses a rectangular waveguide in which the dielectric thin films prepared on a substrate are filled vertically at the center. The frequency dependence of S-parameter measured by network analyzer enables us to calculate the dielectric constant and loss factor of the films at the microwave region through simulation. We prepared Ba0.6Sr0.4TiO3 thin films on (001) MgO single crystal substrate by pulsed laser deposition (PLD), and determined their dielectric constant and loss factor at ∼10GHz using this method.
Synthesis of Nanostructured Magnetic Mixed-Oxide Ferrite Powders by Using A Novel Chemical Method
Authors: Ghosh N N 
Published: June 2019

AbstractIn the present investigation, an attempt has been made to establish a new chemical route for synthesis of the nanostructured mixed oxide ferrite powders. By using this chemical method a variety of ferrite powders having spinel structure and doped with Co, Ni, Mn, Zn etc has been prepared. In this method nitrate salts of the different metals were used as starting materials. The aqueous solutions of the metal nitrates were mixed according to the molar ration of the compositions. Then the mixtures were mixed with an aqueous solution of water soluble polymer (polyvinyl alcohol). This mixture after drying yield fluffy brown powders. These powders were then calcined at different temperatures ranging from 400 °C to 700 °C. Nanostructured powders were obtained from the thermal decomposition of the brown powders. The powders, prepared by calcinations at different temperatures, were characterized by using X-Ray diffraction analysis, IR spectroscopy, TGA/DTA, and TEM. It was observed that the average particle size of the powders are in nanometer scale with a narrow size distribution. The average particle size of the powders was increased with the increase of calcinations temperature.This chemical method has proved to provide a convenient process for the preparation of nanostructured ceramic powders at comparatively low temperatures and offers the potential of being a simple and cost-effective route.
The Effects of Plasma Induced Damage on The Channel Layers of Ion Implanted GaAs MESFETs during Reactive Ion Etching(RIE) and Plasma Ashing Processes
Authors: Ahn Hokyun , Ji Honggu , Mun Jaekyoung , Park Min , Kim Haecheon 
Published: June 2019

AbstractThe gate length of GaAs MESFETs is required to be shorter for higher microwave frequency applications. The side-wall process using silicon nitride is one of the effective processes to fabricate short gate length GaAs MESFETs. The side-wall process consists of deposition and anisotropic etching of silicon nitride and delivers plasma induced damages on the channel layers of the devices. In this study, the effects of plasma induced damage on the channel layers of ion implanted GaAs MESFETs during reactive ion etching and plasma ashing processes have been investigated. The plasma induced damage was characterized by sheet resistance measurement, Xray photoelectron spectroscopy(XPS) and auger electron spectroscopy(AES) of different etched surfaces, compared with a chemically wet-etched reference surface. Also the effect of the plasma induced damage on the device performance was investigated. As a result, plasma ashing can deteriorate the plasma-induced damage by RIE.
RF Sputtered BZN Pyrochlore Thin Films for Voltage Tunable Dielectric Device Applications
Authors: Hong Young Pyo , Ha Seok , Lee Ha Yong , Lee Young Cheol , Ko Kyung Hyun , Kim Dong Wan , Hong Hee Bum , Hong Kug Sun 
Published: June 2019

AbstractThe BZN pyrochlore thin films were prepared on platinized Si substrates using a reactive RF magnetron sputtering. The structures, surface morphologies, dielectric properties and voltage tunable properties of films with deposition parameters were investigated. The BZN thin films have a cubic pyrochlore phase and secondary phases of zinc niobate, bismuth niobate when crystallized at 600° 800°. The dielectric constant and tunability of thin films are O2/Ar ratio and post-annealing temperature dependent. The BZN thin films sputtered in 15% O2 and annealed at 700° had a dielectric constant of 153, tan δof~0.003 and maximum tunability of 14% at 1,000kV/cm.
Correlation of Microwave Dielectric Properties and Microstructure of Unpatterned Ferroelectric Thin Films
Authors: Geyer R. G. , Cole M.W. , Joshi P.C. , Ngo E. , Hubbard C. , Nothwang W. , Bratcher M. , Ervin M. , Wood M. 
Published: June 2019

AbstractThe influence of low concentration (1 mol%) Mg doping on the structural, microstructural, surface morphological and dielectric properties of Ba1-xSrxTiO3 thin films has been measured and analyzed. The films were fabricated on MgO and Pt-Si substrates via the metalorganic solution deposition technique using carboxylate-alkoxide precursors and post deposition annealed at 800 °C (film/MgO substrates) and 750 °C (film/Pt-Si substrates). The structure, microstructure, surface morphology and film/substrate compositional quality were analyzed and correlated to the films dielectric and insulating properties. Dielectric properties of unpatterned films were measured at 10 GHz with a coupled/split dielectric resonator system and at 100 kHz using metal-insulator-metal capacitors. The Mg-doped BST films exhibited improved dielectric loss and insulating characteristics compared to the undoped Ba0.6Sr0.4TiO3 thin films. The improved dielectric properties, low leakage current, and good tunability of the low level Mgdoped BST thin films merit strong potential for utilization in microwave tunable devices.
Microfields Induced by Random Compensated Charge Pairs in Ferroelectric Materials
Authors: Crowne Frank J. , Tidrow Steven C. , Potrepka Daniel M. , Tauber Arthur 
Published: June 2019

AbstractThe dc and microwave responses of the BaxSr1-x (X,Y)yTi1-yO3 family of ferroelectric compounds with various substitutional additives X3+, Y5+ are analyzed by combining the random-field technique with the mean-field (Landau-Devonshire) theory of ferroelectricity, along with a self-consistent computation of the dielectric constant of the host material in the presence of the impurity fields. The fields in the material are assumed to arise from charge compensation at the Ti4+ sites, leading to permanent dipoles made up of the resulting positive and negative ions separated by a few lattice constants. It is shown that whereas completely random placement of positive and negative ions generates a Holtsmark distribution of electric field, with infinite second moment and hence extremely large fluctuations in field strength, the association of ionized impurities into permanent dipoles leads to much lower fluctuations in field and a distribution with finite second moment, which makes a self-consistent dielectric constant meaningful.
An S-Band Reflection-Type Phase Shifter - A Design Example Using Ferroelectrics
Authors: Kim Dongsu , Choi Yoonsu , Allen Mark G. , Kenney J. Stevenson , Stollberg David W. , Kiesling David 
Published: June 2019

AbstractOne of the challenges faced in using ferroelectrics in high frequency devices is how to effectively use the material in a circuit design. A compact reflection-type phase shifter fabricated on sapphire substrates coated with ferroelectric barium strontium titanate (BST) thin-films has been built which shows the promise of using BST thin films in the design of tunable microwave devices. The phase shifter, fabricated as one monolithic assembly, consists of a 3dB coupler, meandered line inductors and tunable interdigital capacitors. A continuously variable phase shift range of more than 100° using the branch-line coupler was obtained at a center frequency of 2.95 GHz, and more than 90° phase shift over 200 MHz bandwidth with a bias voltage range from 0 V to 175 V. The phase shifter using the Lange coupler has over 700 MHz bandwidth centered at 2.2 GHz with a phase shift of more than 90° and an insertion loss less than 2 dB and return loss of greater than 14 dB, over a bias voltage range from 0 V to 160 V. The loss of the BST phase shifter presented in this work is on the order of other commercially available RF front-end components, such as bandpass filters and RF switches. This holds promise for the practical realization of smart antenna systems in cellular handsets and wireless LAN cards.
The Dependence of Dielectric Properties on Composition Variation in Ba0.6Sr0.4(YTa)yTi1-2yO3
Authors: Potrepka Daniel , Tidrow Steven , Tauber Arthur , Kirchner Kevin , Ervin Matthew , Deb Krishna , Rod Bernard , Crowne Frank 
Published: June 2019

AbstractBa0.6Sr0.4(YTa)yTi1-2yO3 has been shown to have properties which are promising for tunable applications requiring low dielectric constant [1]. Ba0.6Sr0.4(YTa)yTi1-2yO3 with y ≤ 0.10 has been synthesized and well-characterized using x-ray diffraction, EDAX, and Raman Spectroscopy. The dependence of the dielectric properties on concentration, y, of Y and Ta are discussed along with implications for improved performance in device applications.
Dielectric and Room Temperature Tunable Properties of Mg-doped Ba0.96Ca0.04Ti0.84Zr0.16O3 Thin Films on Pt/MgO
Authors: Kalkur T.S. , Yi Woo-Chul , Philofsky Elliott , Kammerdine Lee 
Published: June 2019

AbstractMg- doped Ba0.96 Ca0.04 Ti0.84Zr0.16O3 (BCTZ) thin films were fabricated on Pt/MgO substrate by metallorganic decomposition method. The structure of the films were analyzed by x-ray diffraction. The electrical measurements were performed on metal-ferroelectric-metal capacitors with platinum as the top and bottom electrode. The dielectric properties were improved after the capacitors were post annealed at 700 °C in oxygen atmosphere for 30 min. A high dielectric constant of 504 and a dissipation factor of less than 4% was obtained at 1 MHz. The Pt/BCTZ/Pt/MgO capacitors exhibited high tunability of 55% at an applied field of 55 kV/cm.
Microwave Phase Shifters Using Ferroelectric (Ba,Sr)TiO3 Films
Authors: Kim Won-Jeong , Kim Eun-Kyoung , Moon Seung-Eon , Han Seok-Kil , Lee Su-Jae , Kang Kwang-Yong 
Published: June 2019

AbstractThe ferroelectric (Ba0.6Sr0.4)TiO3 (BST) films were prepared on (001) MgO single crystals by pulsed laser deposition. Coplanar waveguide (CPW) type phase shifters controlled by external dc bias field were fabricated on BST films using a 2 μm thick metal layer to reduce metal loss. Microwave properties of the CPW phase shifter were measured using a HP 8510C vector network analyzer from 0.1 – 20 GHz. The fabricated CPW phase shifters (8 mm long) exhibited differential phase angle of 100 ° at 10 GHz with a dc bias field of less than 80 kV/cm between center and ground conductors. Furthermore, a stable differential phase angle (102 ± 3.5 o) was observed from another CPW while changing the power of incident microwave from -10 to +30 dBm. Gap size dependent dielectric constant of the BST film was observed and a simple correction method was suggested in the paper. These results demonstrate the possible application of ferroelectric tunable devices on a high power tunable wireless telecommunication.
Extracellular Matrix Molecules Involved in Barnacle Shell Mineralization
Authors: Fernández María S. , Vergara Italo , Oyarzún Alejandro , Arias José I. , Rodríguez Renato , Wiff Juan P. , Fuenzalida Víctor M. , Arias José L. 
Published: June 2019

AbstractAustromegabalanus psittacusis a large (normally up to 30 cm high) sessile balanomorph barnacle from the coast of Chile and South Peru. Its hard shell is composed of twelve calcareous side plates, six parietes and six radii, joined in the form of a truncated cone opened at the top. Plates rest on a basal disk firmly cemented to the substratum. Although the crystalline microstructure of barnacle's shell has been studied to some extent, its organic composition and the mechanisms governing the biomineralization of such highly ordered nanocomposite have remained obscure. By using X-ray diffraction, infrared spectrometry, SEM and TEM electron microscopy, histochemistry, immuno-histochemistry and -ultrastructure, biochemistry and a crystallization assay, we have studied the cell-shell interactions, the crystalline microstructure of the inorganic moiety and the localization of particular macromolecules, and tested their influence on crystallization.The mineral of the plates and basal disk was calcite showing a (104) preferential orientation. Plates were not solid but porous. While parietes have longitudinal canals (from the base to the apex), radii have transversal canals arranged parallel to the base. These canals are not in the center of the plates but displaced to the outside of the shell delimiting a thinner solid outer lamina and a thicker inner one. The inner lamina consisted of parallel calcified layers separated by organic sheets. These sheets showed autofluorescence and consisted of chitin surrounded by proteoglycans and other minor proteins, which seems to be responsible for the fluorescent behaviour. These organic sheets were also organized as several concentric rings around the canals. The shell matrix obtained after decalcification, which surrounded the crystals, also contained a loose net of such proteoglycans. Mantle epithelial cells covered the entire surface of the inner side of the inner lamina and extend to the plate canals. While isolated chitin did not promote or alter calcite crystallization, the proteoglycan-rich fraction dramatically modified crystal morphology and size. As we have demonstrated in another model of biomineralization, such as the eggshell, hereby we suggest that these structured polyanionic proteoglycan moieties could also be part of the regulatory mechanisms of the barnacle shell mineralization.
Mechanical and Microstructural Properties of Stratum Corneum
Authors: Wu Kenneth S. , Osdol William W. Van , Dauskardt Reinhold H. 
Published: June 2019

AbstractA mechanics approach is presented to study the intercellular delamination resistance and mechanical behavior of stratum corneum (SC) tissue in the direction normal to the skin surface. The effects of temperature and hydration on debonding behavior were also explored. Such understanding, which includes the relationship of mechanical behavior to the underlying SC cellular structure, is essential for emerging transdermal drug delivery technologies. Fracture mechanics-based cantilever-beam specimens were used to determine reproducibly the energy release rates to quantify the cohesive strength of human SC. The debond resistance of fully hydrated SC was found to decrease with increasing temperature, while dehydrated SC exhibited a more complex variation with temperature. Stress-separation tests showed that fracture energies and peak separation stresses decreased with increasing temperature and hydration, although the SC modulus varied only marginally with temperature and hydration. Results are described in terms of microstructural changes associated with hydrophilic regions and intercellular lipid phase transitions.
In Vitro Vascular Cell Adhesion and Proliferation on Alkaline Degraded Poly-lactic/glycolic Acid Polymers
Authors: Webster Thomas J. , Miller Derick C. , Thapa Anil , Haberstroh Karen M. 
Published: June 2019

AbstractThe objective of the present in vitro study was to determine vascular endothelial and smooth muscle cell responses to poly(lactic-co-glycolic acid) (PLGA) films that were exposed apriori to various degrees of alkaline degradation. To model the alkaline environment of blood in arteries, PLGA films were separately soaked in select concentrations (from 0.1 – 10 N) of NaOH for various periods of time (from 10 minutes to 1 hour). Vascular endothelial and smooth muscle cells were then separately allowed to adhere and/or proliferate on the different PLGA degraded surfaces. Results provided the first evidence that smooth muscle adhesion and proliferation increased with larger amounts of alkaline PLGA degradation. In contrast, endothelial cell adhesion and proliferation decreased with increasing amounts of alkaline PLGA degradation. In this manner, the present in vitro study suggests a possible mechanism for insufficient endothelialization on PLGA vascular implants in vivo.