bluuebunny/crossref_metadata_2025_split huggingface dataset:
Piezoresistive Properties of Boron-Doped PECVD Micro- and Polycrystalline Silicon films
Authors: Le Berre M. , Lemiti M. , Barbier D. , Pinard P. , Cali J. , Bustarret E. , Bruyère J.-C. , Sicart J. , Robert J. L. 
Published: April 2011

ABSTRACTThe electrical and piezoresistive properties of in-situ doped PECVD silicon films deposited on oxided silicon wafers have been investigated. One series of films was deposited in the so-called microcrystalline state at 450°C. The other set of samples was deposited in the amorphous state at 320°C and subjected to rapid thermal annealing. Structural properties (grain size, texture, residual stress) were evaluated experimentally through TEM and grazing angle X ray diffraction and related to the measured gauge factor. A maximum longitudinal gauge factor of 28 is measured in the case of advantageously textured microcrystalline material, the magnitude of the gauge factor decreasing sharply for randomly oriented material. For the amorphous deposited and subsequently annealed material, the longitudinal gauge factor is in the range 22–27 depending on dopant concentration. These experimental features are compared to the results of a theoretical approach of piezoresistance in polysilicon. We derive various expressions of the gauge factor according to the assumptions of either constant stress or constant strain within the aggregate. In the case of untextured films, analytical Voigt-Reuss-Hill averages for the elements of piezoresistive and elastoresistive tensors lead to greatly simplified expressions. Theoretical estimates are shown to be in reasonable agreement with the experimental measurements. This confirms the great potential of PECVD microcrystalline and polycrystalline silicon for strain gauges.
Pulsed Laser Deposition of NbNx (0 ≤ x ≤ 1.4) Thin Films
Authors: Treece Randolph E. , Horwitz James S. , Chrisey Douglas B. 
Published: April 2011

ABSTRACTThe structure, morphology, and electrical properties of pulsed laser deposited NbNx (0 ≤ x ≤ 1.4) thin films have been investigated. Films were deposited from Nb metal targets on oriented MgO (100) and amorphous fused silica substrates as a function of substrate temperature and ambient pressure. A reducing atmosphere (N2 with 10% H2) was used to prevent oxide formation. At elevated temperatures, the N/Nb ratios of films deposited on MgO, as determined from Rutherford Backscattering Spectroscopy, increased from 0 −1.4 as the ambient pressure was varied from vacuum to 200 mTorr, respectively. NbNx films (x=l) were deposited at 600 °C and 60 mTorr. Both the structure and electrical properties of the deposited films varied strongly with the substrate type. On fused silica, NbN films were poorly crystalline with low critical temperatures (Tc ∼ 8 – 11 K) and low critical currents (Jc (4.2 K) ∼ 2 MA/cm2), whereas on MgO the NbN films were oriented and had better transport properties (Tc ∼ 16.4 K and Jc (4.2 K) = 7.1 MA/cm2).
Evolution of the Properties of Reactively Sputtered Zirconium Nitrides on Silicon Substrates
Authors: Brande Pierre Vanden , Lucas Stephane , Winand Rene , Renard Lucien , Weymeersch Alain 
Published: April 2011

ABSTRACTZirconium nitride films on silicon substrates have been prepared by DC magnetron enhanced reactive sputtering in a N2/Ar gas mixture under various experimental conditions. The films properties (chemical composition, structure, morphology and optical response) were investigated and related to the experimental conditions. It is shown that these properties are strongly related to the target current density which governs the deposition rate, to the deposit thickness, to the nitrogen partial pressure and to the residual gas contamination. The objective of this paper is to detect the minimum film thickness threshold under which a zirconium nitride coating cannot be used in decorative applications.
Improved Abruptness of Si/Sin Interface by ArF Excimer-Laser Pre-Annealing to Sin
Authors: Uchida Yasutaka , Matsumura Masakiyo 
Published: April 2011

AbstractXPS measurement showed that undesirable SiNH component was reduced drastically from the low-temperature deposited SiN surface by intense ArF excimer-laser irradiation. Although the improved layer was as thin as 15nm, it was very effective to stop diffusion of N atoms from the bottom SiN layer to the top Si layer during the excimer-laser recrystallization step. N-diffused Si layer at the Si/SiN interface was less than the XPS resolution limit for the pre-annealed SiN structure, but about 5nm thick. As a result, the field-effect mobility of the poly-Si/SiN TFT was increased drastically by laser-irradiation to SiN film. Annealing characteristics are also presented for the various SiN film thicknesses and for both the ArF and KrF excimer-laser lights.
A New Offset Gated Poly-Si TFT Using a Wet Oxidation
Authors: Min B.H. , Oh J.M. , Han M.K. 
Published: April 2011

Several off-set gated TFTs have been proposed to reduce the off current. However, those structures may require an additional mask and photolithography process step. We propose a novel off-set gated poly-Si TFT which reduces the off current considerably without any additional mask.We have simulated the device characteristics by a numerical simulator in order to verify the proposed TFT. The simulation results show that the off current of the new device has been reduced to 0.ipA. The reduction of on current is much less than the off current reduction and the on/off current ratios exceeding 107 have been accomplished.
Structural, Optical And Electronic Properties Of Semi-Insulating TIN Oxide Thin Films
Authors: Acutis A. De , Rossi M. C. , Barbetti M. 
Published: April 2011

AbstractBismuth doped SnO2 films with reproducible optical and electronic properties were deposited by spray-pyrolysis on quartz and glass substrates.Deposition temperatures in the range 300°C–360°C were selected and resistivity values in the range 104−1011Ω/square were obtained. Scanning Electron Microscope (SEM) analysis and X-ray diffractometry showed that samples grown at low temperature are amorphous, while at higher deposition temperature the material structure becomes microcrystalline. The spectral transmittance of the films was measured in the UV-VIS range. The absorption coefficients were interpreted to give values of both direct and indirect band gap. The slope of Tauc's plot, which is commonly related to the degree of disorder in the material, confirmed the SEM observations. Conduction mechanisms were also studied through resistivity measurements as a function of deposition temperature. Results obtained for undoped tin oxide were also investigated for comparison.
Transparent Conducting Films Grown By Pulsed Laser Deposition
Authors: Phillips Julia M. , Cava R. J. , Hou S. Y. , Krajewski J. J. , Kwo J. , Marshall J. H. , Peck W. F. , Rapkine D. H. , Thomas G. A. , Dover R. B. Van 
Published: April 2011

AbstractWe have studied the properties of two types of transparent conducting oxides grown by pulsed laser deposition (PLD) on quartz substrates. We have grown films of ITO with resistivity as low as 250 μΩ-cm and with absorption coefficient < 600 cm−1 throughout the visible spectrum. Even films deposited at room temperature can have ρ < 500 μΩ-cm, although the optical transmission characteristics are worse than those of commercially available ITO. Important parameters governing film quality include the oxygen partial pressure during film deposition and substrate temperature. GaInO3 is a recently identified transparent conducting material which is structurally distinct from ITO. Films have been grown with no intentional dopants and with either Ge substitution for Ga or Sn substitution for In. Doping concentrations as high as 10 at. % have been studied. There is no evidence for dopant segregation. Films with resistivities as low as 3 μΩ-cm have been achieved, and the absorption coefficient can be less than 500 cm−1 throughout the entire visible spectrum.
Novel Thin Film Light Emitting Diode Display Made Of Amorphous Silicon-Based Semiconductors
Authors: Kruangam Dusit , Boonkosum Wirote , Panyakeow Somsak , Delong Bancherd 
Published: April 2011

AbstractA novel Thin Film Light Emitting Diode (TFLED) flat panel display was developed. The TFLED is a carrier injection-type electroluminescence and made of hydrogenated amorphous silicon-based semiconductor p-i-n junctions. The amorphous layers employed in this work are for example, a-Si1−xCx:H and a-Si1−xNx:H. The TFLED has two basic structures; 1) glass substrate/ITO/amorphous p-i-n layers/Al and 2) metal sheet substrate amorphous n-i-p layers/ITO. The typical thicknesses of the amorphous p-i-n layers are 150 Å, 500 Å and 500 Å, respectively. The color of the emission can be changed from red to white-blue by increasing the optical energy gap (2.5−3.5 eV), that is the atomic fraction x, in the i-layer. The brightness of the TFLEDs are of the order of 1–10 cd/m2 with injection current density of 100–1000 mA/cm2 and applied voltage of 8–15 V.
Optical Properties Of Silicon Clusters Deposited On The Basal Plane Of Graphite
Authors: Dinh L. N. , Chase L. L. , Balooch M. , Tenninello L.J. , Tench R. J. , Wooten F. 
Published: April 2011

AbstractLaser ablation and post annealing was employed for the synthesis of silicon (Si) clusters on highly oriented pyrolytic graphite surfaces in an ultra high-vacuum environment. The size distribution of the clusters was determined as a function of annealing time and temperature using an in situ scanning tunneling microscope (STM). Pure Si clusters with sizes ranging from 1 to 10 nm showed no detectable photoluminescence (PL) in the visible range. Exposure of these clusters to oxygen at 10−6 Torr and for up to 8 hours showed adsorption of oxygen on the surface of the clusters without Si oxide formation and no detectable PL. Hydrogen termination of these clusters was accomplished by exposing them to atomic hydrogen beam but did not result in any detection of the PL spectra either. Prolonged exposure of these clusters to ambient air, however, resulted in strong PL spectra with color ranging from red to greenish-blue depending on average cluster size. Auger electron spectra (AES) revealed the existence of partially oxidized Si clusters for these samples. This PL could be due to either an oxide phase or to quantum confined Si inner cores.
Non Destructive Thermometry by Means of Microwave Radiometry
Authors: Bocquet B. , Van De Velde J. C. , Mamouni A. , Leroy Y. 
Published: April 2011

ABSTRACTThe measurement of the thermal noise transmitted by lossy materials in the microwave frequency range is, at the present time, the only one thermometric method able to bring information about the temperature distribution inside a material without insertion of any sensor. In this paper, we first briefly recall the principles of the method, and the present state of the experimental set-ups. This technique interest quite different domains of applications such as industrial thermometry, biomedicai engineering, domotics and microelectronics. In other words, the presentation is related to different situations:∼ material at uniform or non uniform temperatures∼ temperatures over or beneath the room, or reference temperature∼ different materials: high or low losses, homogeneous, multilayered or heterogeneous∼ measurement of a thermal noise temperature or of a correlation temperature.The paper analyses also the reasons why these method have not still much penetrated the industrial market and explains the arguments for a future extension of these kinds of applications.
Microwave On-Line Measurements on Conveyed Products Application to Paper and Wood Industries
Authors: Bolomey J.Ch. , Cottard G. , Berthaud P. , Lemaitre A. , Portala J. F. 
Published: April 2011

ABSTRACTMicrowave multiport sensors have been shown to provide some unique capabilities to achieve real-time testing of products conveyed at high speed. In many applications, quantitative measurements of physical quantities such as moisture content, density, etc… are required, either to guarantee reliable production or to optimally control a fabrication/transformation process. In this paper, different ways of extracting such physical quantities from microwave measurements performed by multiport sensors are presented. Model approaches are used, based on polynomial expansions of the physical quantities to be measured as a function of the microwave amplitude and phase data. Calibration procedures have been investigated for both paper and wood material samples. Comparisons between in-situ, microwave and conventional, measurements are analysed.
Evaluation of the Bonded Silicon-on-Insulator Wafer with Lifetime Measurement Using a Non-Contact Laser-Microwave Method
Authors: Usami Akira , Yamaguchi Yuji , Ichimura Masaya , Ishigami Shun-ichiro , Matsuki Kazunori , Takeuchi Tsutomu , Wada Takao 
Published: April 2011

ABSTRACTIn this study, we evaluated the electrical properties of the bonded silicon-on-insulator (SOI) wafers with lifetime measurements using a non-contact laser-microwave method. We prepared one group that consisted of bonded SOI wafers with different active layer thicknesses (I0,30,100μm) and another group consisting of bonded SOI wafers with different buried oxide layer thicknesses(0,0.01,0.1,0.75μm). Primary mode lifetime (τ1) was measured by the photoconductivity decay (PCP) method using the laser diode (λ= 774nm) as a carrier-injected light source. Steady-state change in the conductivity was measured by the photoconductivity modulation (PCM) method using a He-Ne laser (λ = 633nm) as a carrier-injected light source. τ1 decreases as the active layer thickness decreases. The PCM intensity also decreases with decreasing active layer thickness. Surface and interface recombination rates of the SOI are increased with decreasing layer thickness. The PCM intensity also decreases as the buried layer thickness decreases.
Contactless Characterization of the Surface Property of the Si+-Implanted GaAs
Authors: Usami Akira , Yoshida Hideaki , Ichimura Masaya , Wada Takao 
Published: April 2011

ABSTRACTThe surface recombination of GaAs which has a high carrier concentration layer (HCCL) formed by Si+ implantation has been investigated using the reflectance microwave probe (RMP) method. The RMP method enables us to evaluate the surface property of GaAs contactlessly and easily. The experimental results of the samples which were implanted with doses ranging from 1.0×1011 to 3.9×1012cm-2 at an energy of lOOke V indicate that the effective surface recombination velocity decreases with dosage because of HCCL formed after the annealing. On the other hand, the results of the samples which were implanted with a dose of 3.9 × 1012cm-2 at energies ranging from 30 to 180keV indicate that the effective surface recombination velocity increases with energy for energies larger than 50keV. We understood the reason by comparing with the numerical calculation results of an effective surface recombination velocity at a high-low junction interface.
Contactless Mass Determination of Arbitrarily Shaped Objects by Microwave Resonator Measurements
Authors: Kraszewski Andrzej W. , Nelson Stuart O. 
Published: April 2011

ABSTRACTThe basis is presented for using a microwave resonant cavity as an effective “contactless balance”, providing information about the mass of dielectric objects inserted into the cavity. An uncertainty analysis presented in the paper confirms that the mass of small dielectric objects can be determined by this technique with an accuracy better than 4%.
Simulation of Hybrid Heating
Authors: Skamser Daniel J. , Johnson D. Lynn 
Published: April 2011

ABSTRACTA hybrid microwave heating arrangement used to heat alumina fiber preforms has been modeled to determine what conditions are needed to create significant differences in temperature across the specimen while still maintaining control of the temperature. The model assumes a uniform external microwave field and dielectric properties for the specimen as a function of temperature. The results of the model show that significant differences in temperature can be attained while still having control of the temperature at the center. Experiments show that the temperature at the center can be held at 1000°C and still allow a difference in temperature of 50°C between the center and the surface of the specimen to be present.
Growth and Stabilization of Hot Spots in Microwave Heated Ceramic Fibers
Authors: Kriegsmann Gregory A. 
Published: April 2011

ABSTRACTRecently the heating of a thin ceramic cylinder in a single mode applicator was modeled and analyzed assuming a small Biot number and a known uniform electric field through out the sample. The resulting simplified mathematical equations explained the mechanism for the generation and growth of localized regions of high temperature. The results predicted that a hot-spot, once formed, will grow until it consumes the entire sample. Although this phenomenon is seen in some experiments, others show that the hot-spot stabilizes and moves no further.A new model is proposed which incorporates the dependence of the thermal conductivity and the effective heat transfer coefficient upon temperature, and the nonuniformity of the electric field along the fiber axis. The resulting simplified mathematical equations indicate that these effects may stabilize the growth of hot-spots.
Microwave Heating of Carbon Coated Ceramic Fibers
Authors: Kriegsmann G. A. , Wagner B. A. 
Published: April 2011

ABSTRACTThe microwave heating of a thin carbon coated ceramic fiber is modeled and analyzed in the small Biot number regime. The electric field is assumed known and uniform throughout the cross-section, and does not vary along the axis of the cylinder. We present a model which gives a functional relationship between the coating thickness and the final temperature of the fiber. It gives a plausible explanation of the experimentally observed time evolution of temperature for a tow of fibers [1].
Microwave Sintering of Baryum Hexaferrite
Authors: Rousselle D. , Autissier D. , Guillou B. , Leclerc J. 
Published: April 2011

ABSTRACTConventional sintering of baryum hexaferrite Co2Z leads to a mixture of phases with a low density. In this paper we try to obtain a pure densified CO2Z hexaferrite by microwave heating. The design of the applicator is computed from both the electromagnetic physical characteristics, the dimensions and the shape of the hexaferrite sample. The travelling microwave mode is preferred to the resonant one. Microwave process consists in a debinding step followed by the high temperature sintering cycle. Sintering temperature evaluated by infrared sensors seems to be over-valued. A skin effect is observed which can be attributed to electronic conductivity due to high temperature formation of Fe2+ ions.
Improvements on Electrical Properties of Ultra-Thin Silicon Oxides Grown by Microwave Afterglow Oxygen Plasma
Authors: Chen P. C. , Lin J. Y. , Hwang H. L. 
Published: April 2011

ABSTRACTFundamental characteristics such as the oxide breakdown fields, oxide charges and interface state density of various ultra-thin silicon oxides (≤ 8 nm) grown by microwave plasma afterglow oxidation at low temperatures (400 °C and 600 °C) were investigated. The effective Oxide charge density of 600 °C as-grown oxide was as low as 6×1010 cm-2. The breakdown fields of the oxides were further enhanced and the interface state densities were reduced by employing fluorination (HF soaked) and low temperature N2O plasma annealing. The breakdown field of the thin oxide grown at 600 °C with 15 min N2O plasma annealing was 12 MV/cm. The reduction of interface state density was about 35% for 600 °C fluorinated oxide. When integrated with poly-gate process, the interface state density was as low as 5×1010 cm-2eV-1.
Alternative Cavity Design for Microwave Joining of Long Ceramic Tubes
Authors: Sa'adaldin Hussamaldin S. , Black W. Murray , Ahmad Iftikhar , Tian Yong-Lai , Silberglitt Richard 
Published: April 2011

ABSTRACTA new single mode applicator has been designed and fabricated to provide effective and nearly uniform heating of long ceramic tubes or rods at 2.45 GHz. The applicator is made of two double mitered waveguide corners. A comparison between the new cavity and a rectangular cavity has been carried out to heat various ceramic samples. Results show a significant improvement in the heating rate as well as the reduction of the power needed to attain a given temperature. This paper describes the preliminary test results of the new cavity and the potential to achieve joining of long tubes or rods.
Polymer Curing Using Variable Frequency Microwave Processing
Authors: Surret April D. , Lauf Robert J. , Paulauskas Felix L. , Johnson Arvid C. 
Published: April 2011

ABSTRACTEpoxy resin was cured by microwave heating using a variable frequency furnace. Curing behavior and uniformity were characterized by visual inspection, hardness, and differential scanning calorimetry. Frequency sweeping was used as a means of mode stirring to minimize power nonuniformities in the furnace cavity. Cure times were reduced by half and with the appropriate post-cure treatment (also done in the microwave furnace) the resin had a glass transition temperature of 165–175°C. Small amounts of additives such as carbon black and various oxide pigments were tested to determine if they would improve microwave coupling and further reduce cure time. There was little or no effect at a standard concentration of 1 wt% pigment.
Status of Cerium Fluoride Performances
Authors: Auffray E. , Dafinei I. , Lecoq P. , Schneegans M. 
Published: April 2011

ABSTRACTCerium fluoride offers a reasonable compromise between parameters like the density, the light yield, the scintillation characteristics (particularly the decay time) and the radiation hardness, and is considered today as the best candidate for large electromagnetic calorimeters in future High Energy Physics experiments. Details on the performances of large crystals produced by different manufacturers all over the world and measured by the Crystal Clear collaboration will be shown and the usefulness of a good collaboration between the industry and the users will be highlighted by some examples on the light yield and radiation hardness improvement.
The Role of Core Levels in Scintillation Processes
Authors: Belsky Andrey N. , Kamenskikh Irina A. , Vasil'ev Andrey N. , Gektin Alexander V. , Pedrini Christian , Martin Patrick 
Published: April 2011

ABSTRACTThe Auger decay of a core hole results in appearance of several strongly correlated excitations. This excited region strongly polarizes the lattice and thus the defect creation is possible. In all cases the core hole causes the strong local perturbation of electronic and lattice subsystems. The creation of such excited region with mutual relaxation of correlated electrons and holes can result in the increase of the efficiency of energy transfer to activators, acceleration of the luminescence kinetics, and the appearance of radiation-induced luminescence centers.
Dependence of Scintillators Optical Properties on Intrinsic Structural Defects
Authors: Kilassen N.V. 
Published: April 2011

ABSTRACTThe studies of the dependence of the optical properties of various scintillators on intrinsic structural defects have been reviewed. The greater part of the review is devoted to the defects introduced by plastic deformation. A wide range of variations in the light output, spectral distribution, kinetics and other properties has been observed. These defects can be induced during crystal growth, annealing, processing, etc. The proper regulation of the superstructure of intrinsic defects can ensure the production of high quality scintillators having required properties.