bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Critical Point Energies for 1 MeV Electron Irradiated P-Type Silicon
Authors: Russo Onofrio L. , Dumas Katherine A. , Herman Michael H. 
Published: March 2011

ABSTRACTThe critical point energies, E0, E1 and the Lorentz broadening parameter, Γ, for boron doped p-type silicon were obtained by electrolyte-electroreflectance (EER) at 297K and electron beam electroreflectance (EBER) at 297K and 88K. Electron irradiated samples for fluences of 1014 and 1016 e-/cm2 were compared to the samples before irradiation. The value of the low energy weaker structure, Eo and the higher energy main structure, Ei are obtained by the synthesis of two Lorentz line shapes to fit the experimentally obtained composite spectra. The values as determined by EER were all found to increase with radiation as expected. The values for Eo as found by EBER were consistent with those of EER but those of E1 were not.
Metal Induced Crystallization of Amorphous Silicon Thin Films
Authors: Hempel T. , Schoenfeld O. , Veit P. 
Published: March 2011

ABSTRACTThe crystallization behaviour of Ni doped magnetron co-sputtered amorphous silicon thin films (MSP-a-Si(Ni)) has been investigated by means of near infrared-visible-ultraviolet (NIR-VIS-UV) transmission spectroscopy, transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). Using the change in optical transmission spectra of crystallized a-Si(Ni) thin films the crystallization kinetics is described. At the crystallization frontier a needle morphology of single crystals is observed with STEM, which is followed by solid state diffusion of nickel through the amorphous matrix. Using a long term thermal treatment we have studied the formation of expansed monocrystalline networks.
Dose Rate Dependence of the Ion Beam Induced Epitaxial Crystallization in Silicon
Authors: Heera V. , Kögler R. , Skorupa W. , Grötzschel R. 
Published: March 2011

ABSTRACTThe dose rate dependence of 300 keV Si+ ion beam induced epitaxial crystallization (IBIEC) of a 200 nm thick amorphous silicon surface layer at 400°C is investigated in the ion dose rate range from 3 · 1010 up to 3 · 1013cm2s−1. The experimental results are compared with theoretical predictions from several models. Special emphasis is given to the influence of the depth distribution of the nuclear energy deposition on the growth process during both the experiment and the theoretical analysis. According to our experimental results the IBIEC rate is indirectly proportional to the fourth root of the dose rate. This is in excellent agreement with a point defect diffusion model of IBIEC considering pairwise defect annihilation.
Simulator for Dynamic Ion Beam Mixing
Authors: Seidl A. , Fujii K. , Kiuchi M. , Satou M. , Takai M. 
Published: March 2011

ABSTRACTDynamic ion beam mixing (simultaneous deposition and ion beam irradiation) was simulated for the first time. Standard Monte Carlo (MC) programs do not account for the steady change of target geometry caused by the layer growth during the process. Therefore a time-step strategy was realized by integrating a MC simulator in a system together with a geometry update module. A comparison between simulation results and XPS and TEM measurements shows reasonable agreement between simulation and measurements.
The Radiation Phase Transitions and the Metamict State of Quartz
Authors: Sayapina O. V. , Koshkin V. M. 
Published: March 2011

ABSTRACTA model of radiation induced phase transformations in quartz using the old idea of Weissmann and Nakajama is developed. The kinetics of these phase transitions is described taking into account intermediate phase formation. A model of the final radiation induced metamict state of quartz is suggested. The metamict state consists of amorphized matrix SiO2+X, where x ≈0.15 (radioglass), in which pure silicon precipitates are included.
High-Temperature Au Implantation into Ni-Be and Ni-Si Alloys
Authors: James M. R. , Lam N. Q. , Rehn L. E. , Baldo P. M. , Funk L. , Stubbins J. F. 
Published: March 2011

ABSTRACTThe effects of implantation temperature and target composition on the depth distribution of the implanted species were systematically investigated in the present work. Au+ ions were implanted at 300 keV into polycrystalline Ni-Be and Ni-Si alloys at temperatures between 25 and 700 °C to a dose of 1016 cm−2. The depth distributions of Au were analyzed with RBS using He+ at both 1.7 and 3.0 MeV, and those of the other alloying elements by SIMS. Theoretical modeling of compositional redistribution during implantation at elevated temperatures was also carried out with the aid of a comprehensive kinetic model. The analysis indicated that below ∼250 °C, the primary controlling processes were preferential sputtering and displacement mixing, while between 250 and 600 °C radiation-induced segregation was dominant. Above 600 °C, thermal-diffusion effects were most important. A systematic fitting of model calculations to experimental measurements provided values for various defect migration and formation parameters.
A Model to Explain the Variations of “End-of-Range” Defect Densities with Ion Implantation Parameters
Authors: Laanab L. , Bergaud C. , Faye M. M. , Faure J. , Martinez A. , Claverie A. 
Published: March 2011

ABSTRACTComputer simulations in conjunction with TEM experiments have been used to test the different models usually adopted in the literature to explain the formation of “End Of Range”(EOR) defects which appear after annealing of preamorphized silicon layers. Only one survives careful experimental investigations involving Si+, Ge+, Sn+ amorphization at RT and LNT. The “excess-interstitial” model appears relevant at least for a semi-quantitative explanation of the source of point-defects which after recombination and agglomeration, lead to the formation of these defects. This model may be used for the numerical optimization of conditions for the production of high performances ullra-shallow junctions.
F-Centers and Oxygen-Interstitials in MgO
Authors: Scholz C. , Ehrhart P. 
Published: March 2011

ABSTRACTMgO single crystals have been irradiated at different temperatures (4 K, 300 K) with electrons of energies varying between 0.3 and 3 MeV. The irradiation induced defects and their reactions during thermal annealing have been investigated by optical absorption spectroscopy and by X-ray diffraction. The relaxation volume (Viel ≈ 1 at.vol. = a3/8) and the migration energy of the interstitial atoms (≈ 1.6 eV) are determined and an ionization induced and thermally assisted migration process is observed for the first time. The relevance of these results for the understanding of the cascade damage observed after neutron- or ion-damage is discussed.
Temperature and Ion-Mass Dependence of Amorphization Dose for Ion Beam Irradiated Zircon (ZrSiO4)
Authors: Wangl L. M. , Ewing R. C. , Weber W. J. , Eby R. K. 
Published: March 2011

ABSTRACTThe temperature dependence of amorphization dose for zircon under 1.5 MeV Kr ion irradiation has been investigated using the HVEM-Tandem Facility at Argonne National Laboratory. Three regimes were observed in the amorphization dose-temperature curve. In the first regime (15 to 300 K), the critical amorphization dose increased from 3.06 to 4.5 ions/nm2. In the second regime (300 to 473 K), there is little change in the amorphization dose. In the third regime (> 473 K), the amorphization dose increased exponentially to 8.3 ions/nm2 at 913 K. This temperature dependence of amorphization dose can be described by two processes with different activation energies (0.018 and 0.31 eV respectively) which are attributed to close pair recombination in the cascades at low temperatures and radiation-enhanced epitaxial recrystallization at higher temperatures. The upper temperature limit for amorphization of zircon is estimated to be 1100 K. The ion-mass dependence of the amorphization dose (in dpa) has also been discussed in terms of the energy to recoils based on data obtained from He, Ne, Ar, Kr, Xe irradiations and a 238Pu-doped sample.
Enhanced Vortex Pinning and Critical Current Density in Proton-Irradiated YBa2Cu3O7-δ Thin Films
Authors: Venturing E. L. , Siegal M. P. , White A. E. , Hou S. Y. , Phillips Julia M. 
Published: March 2011

ABSTRACTThe appropriate fluence of 2.0 MeV H1 ions has been shown previously to enhance the critical current density Jc by a factor of two at a magnetic field of 0.9 tesla in 1000 Å thick epitaxial films of YBa2Cu3O7-δ grown by the ex situ BaF2 process. The as-grown films exhibit single crystal-like behavior in both atomic ordering and Jc versus temperature and magnetic field. TRIM simulations suggest that H+ irradiation generates mainly point delects throughout the crystal structure. We show here that such defects result in an even greater enhancement of Jc for fields above 1 tesla plus a significant increase in the apparent vortex pinning potential deduced from magnetization relaxation data.
Improvement in Tribomechanical Properties of Commercial TiN Coatings by Argon Ion Implantation
Authors: Liu L. J. , Zhou W. C. , Sood D. K. , Manory R. 
Published: March 2011

ABSTRACTAbout 2 μm thick commercial coatings of TiN on high speed steel substrates were implanted at RT with Ar ions of 95 keV energy to doses between 0.1–1.0×1017 ions/cm2. An ultramicrohardness machine was used to measure hardness, and a (sapphire) ball-on-disk machine to measure wear, friction and adhesion. Hardness enhancements up to about 50% were observed as dose increased. However, at the highest dose, hardness reduced by nearly 2 times the unimplanted value. Friction coefficient and relative wear are correlated and reduce with ion dose. Films undergo brittle fracture during sliding tests. These results are found to be very sensitive to small changes in relative humidity. All implants lead to improved wear and adhesion as compared to an unimplanted surface. These results are discussed in terms of ion damage, accumulation of Ar gas bubbles and a possible break-up of the TiN phase during ion bombardment.
Orientation of Nitrides in N-Implanted Steels
Authors: Leutenecker R. , Cao-Minh U. 
Published: March 2011

ABSTRACTThe impact of irradiation and stresses onto the preferential orientation of hexagonal ε-nitrides in N-implanted steels is investigated. For this purpose, the contribution of the heterogeneous nucleation, which counteracts a preferential orientation, is varied.
Damage Generation by Electronic Excitations in Crystalline Metals
Authors: Dunlop A. , Lesueur D. 
Published: March 2011

EXTENDED ABSTRACTThis paper will give a rapid overview of the main experimental results concerning the effects of high electronic energy deposition in metallic targets and present a tentative model based on the Coulomb explosion mechanism. More detailed reviews have been made recently concerning both the experiments [1–3] and the theoretical model [4].High levels of localized energy deposition in electronic excitation are easily obtained using GeV heavy ions which during their slowing-down typically transfer a few keV/Å to the electronic system of the target and a few eV/Å in elastic collisions with target nuclei. In insulators and organic materials, it is well-known that both slowing-down processes contribute to damage creation, whereas in metals it has been claimed for a long time that the sole nuclear collisions are involved in damage processes. Although this last assertion remains true for some metals such as Cu, Ag, W, Cu3Au …[2], high levels of electronic excitation can induce a partial annealing of the defects resulting from nuclear collisions in Fe, Ni, Nb, Pt…. lead to additional defect creation in Fe, Co, Zr, Ti… [2] or even to phase transformations in NiZr2 [5], Ni3B[6], NiTi [7], Ti [8]… In the following, we shall only focuss on the last two effects.
Amorphization Kinetics of Zr (Cr,Fe)2 Under Ion Irradiation
Authors: Motta A. T. , Howe L. M. , Okamoto P. R. 
Published: March 2011

ABSTRACTThin foils of Zircaloy-4 were irradiated with 350 KeV 40Ar ions in the dual ion beam/HVEM facility at Argonne National Laboratory at 300 – 650 K. The irradiation-induced araorphization of the intermetallic precipitates Zr (Cr, Fe)2 and Zr2 (Ni, Fe) was studied in situ. For Zr (Cr,Fe)2 precipitates the dose-to-amorphization was found to increase exponentially with temperature, with a critical temperature of about 650 K. The amorphization morphology was shown to be homogeneous, with no preferential site for nucleation, in contrast to neutron-irradiation amorphization which started at the precipitate-matrix interface. For Zr2 (Ni,Fe) precipitates it was found that amorphization occurred at 550 K and 600 K, whereas in neutron irradiation no amorphization has been observed at those temperatures. The results are discussed in the context of the previous experimental results of neutron and electron irradiation and likely amorphization mechanisms are proposed.
Effects of Ion Implantation on Crystallization of Amorphous CoSi2
Authors: Hong Q. Z. , Barmak K. , Hong S. Q. , Clevenger L. A. 
Published: March 2011

ABSTRACTThe effects of Si and Kr ion implantation on the crystallization kinetics of amorphous COSi2 have been investigated by differential scanning calorimetry and in situ sheet resistance measurement. Without ion implantation, the crystallization of coevaporated COSi2 is characterized by three dimensional growth from preexisting nuclei. When the as-deposited COSi2 is implanted with Si or Kr ions at liquid nitrogen temperature, the kinetics of the subsequent crystallization is significantly altered. A 180 keV 5×1015 cm−2Si ion implantation increases the crystallization temperature by 34°C. When the Si dose is below 1×1015 cm−2, ion implantation causes a sharp decrease in the crystallization kinetic parameter defined by the Avrami equation. The amount of decrease is shown to scale with the deposited nuclear energy. At higher doses, the kinetic parameter continues to decrease with increasing dose but at a much reduced rate.
Structure Characterization of Metamict and Glassy Lead Phosphates
Authors: Sreeram A. N. , Hobbs L. W. 
Published: March 2011

ABSTRACTSingle crystals of Pb2P2O7 (beam stable under 200 kV TEM electrons to a fluence > 1027 e/m2 and an ionizing dose > 1014 Gy) were rendered metamict (amorphized) with ion-implantation (100 kV P+ ions with several fluences. Pb2P2O7 and PbO·P2O5 glasses were also ion implanted at identical fluences. Radial distribution functions of metamict and glassy phosphates are being generated using energy filtered electron diffraction (EFED) data collected on 100 kV field emission STEM (VG HB-5). Ion-implanted lead phosphate glasses exhibit a significant difference in their FSDP as compared to the non-irradiated ones. XTEM results also show that ion-beam damage layer was around 200 nm deep. XTEM-HREM structure images of ion-implanted single crystals, along with their optical diffraction analysis will be presented and briefly discussed.
Low Energy Focused Ion Beam Processing
Authors: Gamo Kenji 
Published: March 2011

ABSTRACTFocused ion beam (FIB) techniques have many advantages which stem from being maskless and have attracted much interest for various applications includingin situprocessing. However, reduction of damage and improvement of throughput are problems awaiting solution. For reduction of damage, low energy FIB is promising and for improvement of throughput, understanding of the basic processes and optimization of process parameters based on this understanding is crucial. This paper discusses characteristics of low energy FIB system, ion beam assisted etching and ion implantation, and effect of damage with putting emphasize onin situfabrication. Low energy (0.05–25keV) FIB system being developed forms -lOOnm diameter ion beams and is connected with molecular beam epitaxy system. Many results indicate that low damage, maskless ion beam assisted etching is feasible using low energy beams. Recently it was also shown that for ion beam assisted etching of GaAs, pulse irradiation yields very high etching rate of 500/ion. This indicates that the optimization of the relative ratio of ion irradiation and reactant gas supply as important to achieve high etching rate. Low energy FIB is also important for selective doping for high electron mobility heterostructures of GaAs/GaAlAs, because high mobility is significantly degraded by a slight damage.
Deposition of Nano-Scale Ga Dots onto HF-Treated Si(111) Using a Scanning Tunneling Microscope
Authors: Uesugi Katsuhiro , Sakata Kiyoshi , Kawano Seiji , Yoshimura Masamichi , Yao Takafumi 
Published: March 2011

ABSTRACTNano-scale Ga dots are deposited through the decomposition of triethylgallium (TEGa) adsorbed on HF-treated Si(111) surfaces using a scanning tunneling microscope (STM). The deposition of Ga dots of 2–13 nm in diameter is achieved by applying a negative voltage pulse to the sample, while no deposition is observed when a positive voltage pulse is applied. The conditions for Ga deposition are systematically investigated by varying the gap conductance, pulse height, and pulse width. A tentative model for the mechanism of Ga deposition is proposed, in which TEGa molecules are decomposed by the electric field between the tip and the sample.
Pulsed Laser Excited Microwave Photo Conductivity Applications to High Resolution Defect Diagnostics OP Ion and Laser Beam Modified Semiconductor Surface
Authors: Khavroshin D. L. , Manenkov A. A. , Popov S. Yu. , Sokolov S. Yu. 
Published: March 2011

ABSTRACTA novel diagnostic technique for the studies of semiconductor surfaces is described. Experimental data on nonlocal modification effects in laser produced scribing, doping and annealing of ion implanted GaAs and Si are presented. Mechanisms of nonlocal structural and electric properties changes under modification are analyzed. Nonlocality phenomena are concluded to be universal for any strong modification procedure and very important for microelectronics technology.
Measurements of Melting Velocities in Gold Films on a Picosecond Time Scale
Authors: Homan B. E. , Connery M. T. , Harrison D. E. , Macdonald C. A. 
Published: March 2011

ABSTRACTMelting velocities were measured in thin gold films by performing pump/probe transmission measurements using a unique picosecond excimer pump and dye laser probe. Monitoring the depth of the liquid by changes in the near psuedo-Brewster's angle transmission allowed for direct measurement of crystal/melt interfacial velocity up to 1500 m/s.
ArF Laser Induced Photochemical Substitution of OH Radicals into Teflon Surface Using Al(OH)3 Solution
Authors: Okoshi M. , Kashiura H. , Miyokawa T. , Toyoda K. , Murahara M. 
Published: March 2011

ABSTRACTOH radicals were photochemically substituted for fluorine atoms in the teflon surface by using an ArF excimer laser light and an Al(OH)3 solution. This method is simple and can be performed in air atmosphere. In the process, the teflon film was placed on the Al(OH)3 which were dissolved in NaOH water solution; the ArF excimer laser light was irradiated the sample surface and the solution. By irradiating the laser, the surface was defluorinated by the aluminium atoms photodissociated from the Al(OH)3 solution, and the dangling bonds which were formed in the defluorinated surface combined with the OH radicals also photodissociated. The hydrophilic property of the photomodified surface was evaluated by the measurement of the contact angle with water. The defluorination and the OH radicals substitution were inspected by the XPS analysis and the ATR-FTIR measurement.
Defect Penetration During the Plasma Etching of Semiconductors
Authors: Rahman M. , Foad M. A. , Hicks S. , Holland M. C. , Wilkinson C. D. W. 
Published: March 2011

ABSTRACTDry etching can introduce defects into the material being etched. Simple expressions for both sidewall and top surface defect distributions may be obtained by assuming that the defects are introduced according to a phenomenological source function. Calculations of conductance based on these expressions are found to describe very well measurements on dry-etched wires and epilayers. Mechanisms by which defects can penetrate into the sample are discussed. The role of sample heating and defect diffusion is examined. In-situ measurements of sample temperature during a dry-etch run indicate that simple diffusion is insufficient to account entirely for the observed damage. Instead, dry-etch damage may arise from other mechanisms such as by knock-on replacement collisions, or via a channeling effect. A more complex form of diffusion may also affect the final damage distribution.
Ultrapure Iron Film Formation by Mass-Separated Ion Beam Deposition Method
Authors: Miyake Kiyoshi , Ohashi Kenya , Komuro Matahiro 
Published: March 2011

ABSTRACTIsotopically enriched iron (56Fe or 57Fe) films were deposited on Si(100) substrates at RT by a low-energy (50–500 eV), mass-separated ion beam deposition (IBD) method. All the IBD-Fe films had smooth and fine-grained polycrystalline bcc-structure, and showed superior electrochemical corrosion resistance against both NaCl and H2SO4 solutions compared with die highest-purity (RRRIH=6000) iron metals ever reported. A distinct energy dependence of the degree of corrosion resistance and different microcrystalline structures observed by TEM cross-sections for the 50 eV- and 100 eV-IBD-Fe films indicate that their film growth modes are completely different.
Epitaxial Growth of MgO Single Crystal Thin Film in Oxygen Atmosphere
Authors: Yang M. H. , Flynn C. P. 
Published: March 2011

ABSTRACTWe have studied the epitaxial growth of MgO single crystal thin films by depositing Mg onto MgO substrates in an oxygen atmosphere. This method provides a simple way to dope Mg18O layers uniformly into Mg16O. The well controlled layer thicknesses are suitable for bulk diffusion studies both in the MgO epilayer and the MgO substrate. The MgO growth rate was measured and found to be proportional to the Mg flux and to the square root of oxygen pressure at a given temperature, obeying the law of mass action. High quality MgO single crystal thin films, as indicated by RHEED and x-ray diffraction, were found to grow over u wide temperature range, as in the earlier work1 using e-beam evaporation.
Formation of Well-Separated Buried and Surface Nickel-Silicide Layers in a Single Ion Implantation Step
Authors: Wu M. F. , De Wachter J. , Hendrickx P. , Pattyn H. , Van Bavel A. M. , Langouche G. , Vanhellemont J. , Bender H. , Maenhoudt M. , Bruynseraede Y. 
Published: March 2011

ABSTRACTAn unusual Ni distribution with two completely separated buried and surface suicide layers has been observed after Ni ion implantation in Si(111) kept at a temperature of 300° C, with a dose of 1.1 × 1017/cm2 and at a fixed energy of 90 keV. RBS/channeling, AES and cross-sectional TEM have been used to study this phenomenon as a function of the substrate temperature and Co co4mplantation. A model is presented, based on the diffusion of the transition metal, the defect annealing during the implantation, and the gettering power of the surface and the end of range defects.
Substrate and Particle Dependent Deep Level Generation in Silicon by MeV Particle Beams
Authors: Trauwaert M.-A. , Vanhellemont J. , Simoen E. , Claeys C. , Johlander B. , Harboe-Sörensen R. , Adams L. , Clauws P. 
Published: March 2011

ABSTRACTThe results are presented of a fundamental study of electrically active damage introduced in silicon diodes by irradiation with the fission products resulting from the decay of a 252Cf source and with high energy protons. The influence of the oxygen content of the silicon substrate and the irradiation type on the damage formation is investigated using deep level transient spectroscopy. A radiation hardening effect by interstitial oxygen is observed. Bom types of irradiation create the same dominant defect levels but with different relative densities. The identification of the induced deep levels are confirmed by isochronal annealing results.