bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion Channeling Analysis of Disorder
Authors: Picraux S. T. 
Published: March 2011

ABSTRACTThe use of ion channeling to characterize disorder in semiconductors is briefly reviewed. At high defect densities the ion channeling/backscattering technique can give the depth distribution of defects with a resolution ∼ 10 nm. Quantitative analysis of the defect depth profile requires that a single type of defect dominates the scattering of partiicles out of channeling trajectories. This scattering process is characterized by two defect-specific quantities: the direct scattering factor and the dechanneling cross-section. For impurity-associated defects the lattice location of the impurity atoms can be determined to within ∼ 0.1 Å by simultaneously measuring the impurity and host atom signals as a function of tilt angle about channeling directions. The channeling technique can detect a wide range of intrinsic defects including interstitials, dislocations, stacking faults, microtwins, and amorphous clusters. Examples of the application of channeling to study defects in silicon will be given for the cases: 1) hydrogen trapping at defects; 2) ion implantation doping; and 3) epitaxial growth of layers.
Dislocation Nucleation Models From Point Defect Condensations in Silicon and Germanium
Authors: Tan T.Y. 
Published: March 2011

ABSTRACTThe process of dislocation nucleation from point defect condensations in Si(Ge) is discussed. Based on the assumption that during the dislocation nucleation stage, the dominant factor in the configurational energy is the number of dangling bonds per point defect incorporated, rather than the more commonly recognized factor of strain energy, it is possible to model the dislocation nucleation process. In order to minimize the number of dangling bonds, point defects would condense into row configurations elongated in <110>, called intermediate defects (IDC), and then the IDCs would evolute into undissociated 90° edge –, 60°, and Frank partial dislocations.
Characterization of Defects in Silicon Ribbons By Combined Ebic and Hvem
Authors: Strunk Horst , Cunningham Brian , Ast Dieter 
Published: March 2011

ABSTRACTThe electrical properties and crystallographic nature of linear and planar defects in EFG silicon ribbons were studied. A direct correlation between electrical and structural properties was obtained by imaging the same areas first with EBIC and then with HVEM. Coherent twin boundaries were found to be electrically inactive, but higher order twins and other grain boundaries generally enhanced minority carrier recombination. Partial dislocations confined to coherent twin boundaries were usually electrically active, but in certain instances partial dislocations were observed which had no apparent EBIC contrast.
Precipitation of Oxygen and Intrinsic Gettering in Silicon
Authors: TICE W. K. , Tan T. Y. 
Published: March 2011

ABSTRACTIn this review, dislocations introduced by prismatic punching at SiO2precipitate sites in Czochralski silicon are shown to act as metal adsorption centers. Conditions necessary to localize SiO2precipitate and dislocation complexes in wafer regions remote from semiconductor devices are discussed. This localization achieves an intrinsic gettering effect. The application of the intrinsic gettering mechanism to bipolar and MOS device technologies is shown to improve device performance and leakage limited yields.
Convection and Constitutional Supercooling Cells in Laser Annealed Silicon
Authors: Narayan J. , Fletcher J. 
Published: March 2011

ABSTRACTThe formation of convection and constitutional supercooling induced cells has been studied in indium implanted, laser annealed silicon using plan-view and cross-section electron microscopy. The convection cells were associated with the spatial inhomogeneity in the laser pulse, which leads to large temperature gradients in the lateral direction. The average size of constitutional supercooling cells decreases with increasing velocity of solidification, and it also decreases from (111) orientation to (100). The results of a perturbation theory will be discussed, which predicts the cell size and limiting concentration of instability as a function of velocity of solidification.
Tem Investigation of the Microstructure in Laser-Crystallized Ge Films
Authors: Gale Ronald P. , Fan John C. C. , Chapman Ralph L. , Zeiger Herbert J. 
Published: March 2011

ABSTRACTThe crystallite morphology and defect structure of laser-crystallized Ge films have been characterized by transmission (TEM) and scanning (SEM) electron microscopy. The elongated crystallites present in these films have their long axis in the [001] direction. In regions where these crystallites are well aligned with each other, competitive lateral growth and (110) texture are observed. The defects most frequently found are [111] microtwins. A growth model that accounts for the texture and defects is proposed.
Effects Of Damage-Impurity Interaction On Electrical Properties of Se+-Implanted GaAs
Authors: Sadana D. K. , Washburn J. , Strathman M. D. , Booker G. R. , Badawi M. H. 
Published: March 2011

ABSTRACTInteraction of impurities with the “visible defects” in hot implanted Cr doped semi-insulating (100) GaAs has been investigated. The defects studies were performed using transmission electron microscopy (TEM) and MeV He+ channeled Rutherford backscattering. The defects distribution was obtained by 90° cross-sectional TEM (XTEM). The atomic concentration profiles of Se, and carrier-concentration and mobility profiles were obtained by secondary ion mass spectrometry (SIMS) and Hall measurements in conjunction with chemical stopping, respectively. Comparison of defects, atomic and electrical profiles, showed the formation of secondary defects at and beyond the projected range (Rp), a significant amount of Se+ diffusion beyond Rp, and compensation of electrical carriers caused mainly by the point defects present in hot implanted GaAs.
Fermi Surfaces of Acceptor Intercalated Compounds: Evidence Frov Asf5-Graphite
Authors: Markiewicz R.S. , Lopatin C. , Zahopoulos C. 
Published: March 2011

ABSTRACTWe find that the carrier concentration in Stage II AsF5- graphite can be varied over a wide range, f≃.30–.46. By studying the Fermi surfaces vs. f via magnetooscillations, we find that the band parameters are essentially unchanged from pure graphite. Thus suggests that all stage two compounds should display a universal behavior as a function of f, and we adduce evidence of this from the literature. We further begin an analysis of extra oscillation frequencies. In AsF5-graphite, mixing frequencies are probably caused by Fermi-level modulation (Vinter-Overhauser effect), while a low frequency (β) is associated with a superlattice.
Electronic Transport Properties of Graphite Acceptor Compounds
Authors: Spain Ian L. , Volin Kenneth J. 
Published: March 2011

ABSTRACTCalculations of the magnetoresistance of graphite acceptor compounds are made using a tight binding model for the carrier dispersion proposed by Blinowski et al, and measured values of the zero-field resistivity. It is shown that, if a reasonable physical model is used for the mobilities, the magnetoresistance cannot be fitted with two- or three-carrier models. Suggestions for the origin of the magnetoresistance are made.
Magnetic Heat Capacity of Stage 2 Graphite-Coc12
Authors: Shayegan M. , Salamanca-Riba L. , Heremans J. , Dresselhaus G. , Issi J-P. 
Published: March 2011

ABSTRACTThe heat capacity Cp of graphite-CoC12 (stage 2) is measured at zero and high (up to 14 T) magnetic fields (H applied in-plane). By suppressing the magnetic contribution to Cp at the highest fields, we are able to decompose Cp into its electronic, lattice, and magnetic contributions. The magnetic heat capacity CM is seen to have a broad peak at ⋍ 9.1 K. The shape of this peak is consistent with the reported Monte Carlo calculations of CM based on a twodimensional xy model.
Ambient Temperature Alkali Metal Transfer in Hydrocarbons - A New Route to Intercalation Compounds and Alloys
Authors: Besenhard J.O. , Kain I. , Klein H.-F. , MöHwald H. , Witty H. 
Published: March 2011

ABSTRACTDissolved cobalt(0) complexes of the type [L3L'Co] (L = phosphanes, e.g. PMe3, L' = olefins, e.g. C2H4) are reversibly reduced by alkali metals A (A = Li, K, Rb, Cs)n[L3L'Co] + A ⇋ A[L3L'Co]and hence can be used as A-carriers. These carrier complexes A[L3L'Co]n are even soluble in apolar solvents like pentane.Action of [L3L'Co] plus A in pentane solution on graphite yields binary intercalation compounds ACn. By contrast, conventional ambient temperature A-transfer reagents (e.g. solutions of A in naphthalene-ether or in NH3) require strongly polar solvents and yield ternary intercalation compounds A(solv)yCn.The “reducing power” of the alkali cobaltates is close to that of free A: alkali-rich phases like 1st stage KC8 or LiC6 or highly doped polyacetylenes (e.g. K(CH)5) are readily prepared. If intercalation of solvated species is unlikely, the A-transfer reactions may also be performed in polar solvents like ethers.
Temperature Gradient Enhancement of Solid State Battery Performance
Authors: Borey Bruce K. , Horne Frederick H. 
Published: March 2011

ABSTRACTThe equations of nonequilibrium thermodynamics are used to investigate how temperature gradients may be utilized to enhance performance of solid state batteries. One result is that the efficiency of a battery with doped cerium oxide as the electrolyte may be increased by imposition of a temperature gradient. This may lead to greater use of electrolytes of appreciable electronic conductivity. Moreover, temperature gradients may be used to increase mobile ion diffusivity in intercalation electrodes during battery discharge and recharge.
In Situ Raman Scattering Studies of the Electrochemical Intercalation of Graphite in Sulfuric Acid
Authors: Olk C.H. , Yeh V. , Holler F.J. , Eklund P.C. 
Published: March 2011

ABSTRACTIn situ Raman scattering studies of the high-frequency carbon intralayer modes in graphite-H2SO4 have been carried out during the electrochemical intercalation of graphite in sulfuric acid. The data show that within an optical depth of ∼ 200 Å the entire c-face undergoes a sudden transition to the next lower stage (n−1) at the moment when the bulk has just completed forming stage n. Raman data collected in the “overcharge” and “overoxidation” regimes of the electrochemical synthesis indicate rapid shifting of the peaks during these times, indicating a significant increase in the oxidation of the carbon layers.
121Sb MöSsbauer Studies of Graphite–SbF5 Intercalation Compounds
Authors: Mcdaniel D. H. , Boolchand P. , Bresser W. J. , Eklund P. C. 
Published: March 2011

ABSTRACTStage 2 samples of graphite-SbF5 intercalVtion compounds were prepared by reacting SbF5 with HOPG at 200°C for 5 days. 121Sb Mössbauer spectra taken at 4.2K reveal an intense and narrow feature in the Sb(5+) region and a weak and broad feature in the Sb(3+) region. Interpretation of these data in terms of possible Sb(5+) and Sb(3+) intercalant species is discussed in connection with chemical aspects of intercalation.
121Sb Mössbauer Studies On No2SbF6 Intercalated Graphite
Authors: Boolchand P. , Bresser W. , Mcdaniel D. , Eklund P.C. , Billaud D. , Fischer J.E. 
Published: March 2011

AbstractWe have examined graphite salts of the composition C23nSbF6(CH3NO2)1,7 n = 1,2 by121Sb Mössbauer spectroscopy at 4.2K. The spectra reveal a strong and narrow feature in the Sb5+ region and no evidence of any features in the Sb3+ region. This result is in general accord with the expectation of only Sb5+ in the chemical form of SbF6− anion in the intercalate layers.
Electrical Properties of Sbcl5, Icl, Hno3, and Br2 Intercalated Pitch Based Carbon Fibers
Authors: Natarajan V. , Woollam John A. 
Published: March 2011

ABSTRACTHighly graphitized pitch based carbon fibers with heat treatment temperatures (HTT) of 2500°C, and 3000°C have been intercalated with SbCl5, ICl, HNO3, and Br2. These were reacted either by themselves alone, or in double sequence (e.g. Br2 followed by SbCl5). The electrical resistivities of individual fibers were then measured in air, and as a function of temperature, to a series of temperatures, to test air and thermal stability. The lowest resistivity found in this sequence so far is 28 micro ohm cm when ICl intercalation was followed by HNO3 reaction. These conductors are sometimes air stable (depending on intercalant) at room temperature and can be heated somewhat, but begin to deintercalate at much lower temperatures than was found for CuCl2 intercalated fibers [1,2]. In comparison with the CuCl2 reaction with pitch fibers, these intercalants react easily, and thesequential intercalations appear to give lower final resistivities.
Optical Reflectance Studies of Stage 1-4 Graphite-Sbcl5 Intercalation Compounds in the Range 0.2-10 eV
Authors: Heinz R. E. , Doll G. , Charron P. , Eklund P. C. 
Published: March 2011

ABSTRACTWe report optical reflectance measurements on stage 1-4 graphite-SbCl5 intercalation compounds in the energy range 0.2 to 10 eV. The data are analyzed using a Kramers-Kroniq relation to determine the parameters describing the intraband and interband contributions to the dielectric functions ∊1(ω) and ∊2(ω). Structure in these functions are compared with recent band calculations by Blinowski et al.
Commensurate-Glass Phase Transitions in Staged Sbcl5-GIC
Authors: Salamanca-Riba L. , Timp G. , Hobbs L.W. , Dresselhaus M.S. 
Published: March 2011

ABSTRACTAn experimental study is reported of the commensurate (√7 × √7)R19.1° to glass phase transition in stages I < n > 4 graphite-SbCl5 using electron and x-ray diffraction. The electron diffraction studies show an in-plane phase transition to a glass at low temperatures. The (00l) x-ray diffraction scans show that the c-axis layered structure of the intercalate is unchanged by the phase transition. A driving mechanism for the commensurate to glass transition is suggested.
Ferroelectric Thin Films on Silicon and Fused Silica Substrates by Sol-Gel Process
Authors: Xu Yuhuan , Chen Ching Jih , Xu Ren , Mackenzie John D. 
Published: March 2011

ABSTRACTFerroelectric thin films including undoped and doped PZT (lead zirconate titanate), BaTiO3 (barium titanate), SBN (strontium barium niobate), KNbO3 (potassium niobate), PBN (lead barium niobate), KNSBN (potassium sodium strontium barium niobate), and LiNbO3 (lithium niobate) were made on silicon and fused silica substrates by a sol-gel process. Microstructure and physical (pyroelectric, ferroelectric and optical) properties of these thin films were studied. Transparent and preferentially orientated SBN thin films on fused silica substrates can be obtained by applying a d.c. electric field during heat treatment. A heterojunction effect was observed in ferroelectric thin films on both n-silicon and p-silicon through measurement of I-V characteristics, and by the demonstration of a photocurrent effect.
Processing, Perovskite Phase Development, and Dielectric Properties for Sol-Gel Derived Pb[(Mg1/3Nb2/3)0.9Ti0.1]O3 Thin Layers
Authors: Francis Lorraine Falter , payne D. A. 
Published: March 2011

ABSTRACTAlkoxide-based solutions were synthesized and used to prepare Pb[(Mg1/3Nb2/3)0.90Ti0.10]O3 (90PMNT) thin layers on platinized Si. A multilayering spin casting method was used. The effects of preparation procedure, additives, and intermediate heat-treatments on perovskite phase content, microstructure development and dielectric properties are reported. The greatest perovskite content (∼99%) and the best dielectric properties (K ≈ 1500–2000, tan∂ ≈ 0.03 at 100 kHz) resulted from rapid thermal processing of individual layers at 800°C. Polarization-reversal measurements are also reported.
Stresses in Ferroelectric Thin Films
Authors: Desu Seshu B. 
Published: March 2011

ABSTRACTThe stresses in rf sputtered BaTiO3 thin films, deposited on both Si and sapphire single crystals, were studied. From the measured total film stress values, both the intrinsic stresses in the film and the elastic coefficients [Ef/(1–vf)] of the film were obtained. BaTiO3 films can be obtained in any stress state (tensile, stress free or compressive) by varying the deposition temperature, deposition pressure, and substrate. At lower temperatures and pressures compressive intrinsic stresses were observed whereas, at high deposition temperatures and pressures intrinsic stresses were tensile in nature. The [Ef/(1–vf)] value approached the single crystal value for films deposited at low pressures and decreased significantly with increasing deposition pressure.
Early Stages of Growth of BaTiO3 Thin-Films
Authors: Norton M. Grant , English Gerald R. , Carter C. Barry 
Published: March 2011

ABSTRACTBarium titanate (BaTiO3) is of interest for use in a number of thin-film applications in electronic and optoelectronic devices. For these devices the formation of epitactic films of the correct stoichiometry and phase is essential. The substrate is important during the early stages of growth in the establishment of epitaxy, factors such as lattice mismatch, surface preparation and crystallographic orientation can all affect film nucleation and growth. In this study thin-films of BaTiO3 have been formed using the pulsed-laser ablation technique. The early stages of film growth have been studied directly using transmission electron microscopy by examination of very thin films deposited onto specially prepared electron-transparent thin-foil substrates.
Interface Structure and Dielectric Properties of SrTiO3 Thin Film Sputter-Deposited onto Si Substrates
Authors: Matsubara S. , Sakuma T. , Yamamichi S. , Yamaguchi H. , Miyasaka Y. 
Published: March 2011

ABSTRACTSrTiO3 thin film preparation onto Si substrates using RF magnetron sputtering has been studied for a high capacitance density required for the next generation of LSI's. Structural and chemical analysis on the interface between SrTiO3 film and Si was carried out with cross-sectional TEM, EDX, and AES. Dielectric properties were measured on AuTi/SrTiO3/Si/Ti/Au capacitors. The as-grown dielectric films on Si were analyzed and found to consist of three layers; SiO2, amorphous SrTiO3 and crystalline SrTiO3, from interface toward film surface. By annealing at 600 °C, the amorphous SrTiO3 layer was recrystallized, and consequently the capacitance value increased. A typical specific capacitance was 4.7 fF/μm2 and the leakage current was in the order of 10−8 A/cm2, for 180 nm thick SrTiO3 film. The dielectric constant decreased from 147 to 56 with decreasing SrTiO3 film thickness from 480 nm to 80 nm. This is due to the low dielectric constant SiO2 layer (ε=3.9) at the interface. From the film thickness dependence of the ε value, the SiO2 layer thickness was calculated to be 3.9 nm, which agreed well with the value directly observed in the TEM.To avoid SiO2 layer formation, barrier layers between SrTiO3 and Si have been studied. Among various refractory and noble metals, RuSi and a multi-layer of Pt/Ti have been found to be promising candidates for the barrier material. When RuSi film or Pt/Ti film was formed between SrTiO3 film and Si substrate, dielectric constant of about 190 was obtained in dependent of the SrTiO3 film thickness in the range of 80–250 nm. Analysis on the barrier layers was performed by means of RBS, XPS and XRD.
Fatigue and Aging in Sol-Gel Derived PZT Thin Films
Authors: Shepherd W.H. 
Published: March 2011

ABSTRACTTypical fatigue and aging characteristics are reported for thin PZT films prepared using sol-gels. The fatigue process occurs in two steps. There is an initial period, during which the domain matrix of the as formed film is restructured by the cycling and the polarization generally increases, followed by a period in which the polarization decays. The polarization decay may be due, in part, to the formation of dielectric layers at the electrodes. The effects of voltage and temperature on fatigue are reported. Aging is examined as a function of temperature. Measurements of internal bias fields do not support the view that they are the primary cause of aging. Neither fatigue nor aging are temperature sensitive making identification of specific physical processes difficult.
Size Effects in Sputtered PZT Thin Films
Authors: Desu Seshu B. , Peng Chien H. , Kammerdiner Lee , Schuele Paul J. 
Published: March 2011

ABSTRACTThe ferroelectric properties and switching characteristics of rf sputtered PZT thin films were investigated as a function of film thickness (30–300 nm) and grain size. Electron microscopy was used to characterize the film microstructure. The film thickness was measured by ellipsometer. The results were analyzed for the individual contributions of film thickness and crystallite dimension to the size effects on the properties of ferroelectric thin films. A critical discussion of several different models describing the size effects was also presented.
Processing and Structural Characterization of Ferroelectric Thin Films Deposited by Ion Beam Sputtering
Authors: Ameen M. S. , Graettinger T. M. , Rou S. H. , Al-Shareef H. N. , Gifford K. D. , Auciello O. , Kingon A. I. 
Published: March 2011

ABSTRACTAn analysis is presented of the ion beam sputter deposition of ferroelectric KNbO3 and Pb(Zr, Ti)O3 (PZT), and the observed compositional, structural, and microstructural properties of these films. Films are deposited using a specially designed computer-controlled system with ability to produce multicomponent films via layer-by-layer deposition of elemental components. Metal or oxide targets are sequentially exposed to a high current ion beam by means of a rotatable target holder. A quartz crystal resonator provides feedback information on layer thicknesses to the computer. Precise control of film stoichiometry is obtained using this method.KNbO3, a material possessing a high figure-of-merit for electrooptic applications, has been deposited epitaxially on (100) MgO substrates. The structure of the optically transparent films has been studied with x-ray and electron diffraction, and transmission electron microscopy. The effects of various processing parameters on the microstructure of the films are discussed.We have demonstrated the ability of the technique to produce multicomponent films and control cation concentration at elevated substrate temperatures for materials such as PZT. The microstructure and associated ferroelectric properties are discussed in relation to processing conditions.
Pulsed Laser Deposition of Metal Dichalcogenides on Stainless Steel
Authors: John P. J. , Dyhouse V. J. , McDevitt N. T. , Safriet A. , Zabinski J. S. , Donley M. S. 
Published: March 2011

AbstractFilms of MoS2 have been successfully deposited on 440C stainless steel using an excimer laser. A comparison was made of films ablated with the laser operating at 193 nm and at 248 nm. The effects of substrate temperature were also studied. X-ray Photoelectron Spectroscopy (XPS) measurements indicated that the films were sulphur rich as compared to single crystal MoS2. Laser Raman measurements indicated that annealing was necessary to obtain crystalline films. All films exhibited coefficients of friction in the neighborhood of 0.03 in a dry nitrogen environment. Coefficients of friction in laboratory air were significantly higher.