bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Possible Importance of Pressure in Metastable Precipitate Formation in Ion Implanted Metals
Authors: Evans John H. 
Published: March 2011

ABSTRACTPrompted by the recent discovery that the heavier inert gas atoms implanted into metals precipitate in the solid phase, indicative of very high pressures (,>,1 GPa), the present paper discusses the conditions under which such pressures might be expected. The metal/inert gas results are briefly described and then used as a model to show that the two essential features apart from low or moderate metal temperatures, are the insolubility of the implanted species in the host matrix and its precipitation on a very fine scale. This combination suppresses the bias-driven cavity swelling that would otherwise control vacancy acquisition in an irradiation environment.The extrapolation to other combinations of implanted ion and metal will be discussed. Where the implanted ion is insoluble and precipitates on a scale similar to the inert gas atoms, exact analogy suggests that the precipitates will again be under high pressure. The formation of high pressure phases might not be unexpected and could be a factor in explaining the presence of phases previously thought to be metastable.
Lattice Mode Study of La2CuO4-y Implanted with Sr
Authors: Ohana I. , Doll G. L. , Lusnikov A. , Withrow S. P. , Picone P. J. , Dresselhaus M. S. , Dresselhaus G. , Jenssen H. P. , Gabbe D. R. 
Published: March 2011

ABSTRACTDramatic implantation-induced changes in the Raman and infrared spectra of polycrystalline samples of La2CuO4-y are reported for implantation of Sr in the fluence range 0.5 to 1.5 × 1016/cm2. The Raman and ir-reflectance spectra of the Sr implanted material reveal disorder-induced lines corresponding to breakdown of selection rules and to non-zone-center phonon modes. Whereas the main features in the Raman spectra of the implanted sample are broad disorder-induced lines centered at ∼ 560 ± 5 cm−1, reststrahlen lineshapes are observed above ∼ 800 cm−1 in the ir-reflectance spectra. After thermal annealing (550°C), the multiphonon lines in the ir spectra diminish, and the disorder-induced lines in the Raman spectra split to form well-resolved, sharper lines at 530 and 580 cm−1, identified with maxima in the phonon density of states. The sensitivity and complementarity of Raman and infrared spectroscopy to implantation-induced disorder and subsequent partial recovery by thermal annealing suggest that these techniques can be used to characterize sensitively disorder in ion implanted La2CuO4-y high Tc, materials.
A Study of Damage in Silicon Created By and P+ Implantation
Authors: Ziwei Fang , Chenglu Lin , Shihchang Tsou 
Published: March 2011

ABSTRACTThe damage and annealing behavior of <100> Si implanted at room temperature by and P+ at different energies (5-600KeV) and intermediate dose (∼1014/cm2) has been investigated. Experimental results show that the damage created by implantation is always greater than that of P+ implantation. The ratio of total displaced atoms of the target cuased by molecular and atomic implantation, ND(mol)d/ND(atom) reached a maximal value at 100KeV () and 50KeV (P+) after rapid thermal annealing, the carrier concentration profiles measured by spreading resistance measurements are also different for the and P+ implanted samples. We attribute essentially this phenomenon to the displacement spike, but the multiple collision effect and the interaction between two molecular fragments should be considered while the incident energy is high.
Synthesis of Iron Oxynitride by Nitrogen Ion Implantation of Iron Oxide
Authors: Ogale S. B. , Teli Seema , Chopda Sunita , Phase D. M. , Kanetkar S. M. 
Published: March 2011

ABSTRACTThe effect of N2+ ion implantation in ∝-Fe2O3 has been investigated by means of Conversion Electron Mossbauer Spectroscopy (CEMS). It Is shown that at a dose value of 1×1017 ions/cm2 and 3×1017 Ions/cm2 the samples exhibit new Interesting hyperfine features which can not be ascribed to known oxide or nitride phases. It Is thus concluded that Iron Oxynitrlde Is formed by the nitrogen Implantation process.
Characterisation of Ion Implanted and Thin Epitaxial Layer Structures Using Photoluminescence
Authors: Hamilton B. , Sedgwick T. O. , Gelpey J. C. 
Published: March 2011

ABSTRACTPhotoluminescence (PL) measurements of thin rapidly annealed As implants have been made. The experimental conditions required to enhance the PL signal from the implant region have been established. Our data suggest that residual defects within the implanted volume can completely quench the PL signal. For the range of anneal times investigated (0.3s to 10s) we find that temperatures above 1050°C are needed to remove these defects. Anneal temperatures of 1350°C remove the defects sufficiently to allow us to observe strong PL from the implanted volume..
Solid Phase Epitaxy of Implanted Silicon by Electron Irradiation at Room Temperature
Authors: Lulli G. , Merli P. G. , Antisari M. Vittori 
Published: March 2011

ABSTRACTSolid-phase epitaxy of implanted Si is observed at room temperature during in situ electron irradiation in a Transmission Electron Microscope. Results obtained from irradiation of cross sections of samples containing different doping species show that: i) the basic mechanism of the process is the migration and recombination at the amorphous-crystalline interface of radiation defects coming both from the amorphous and crystalline side; ii) the diffusion length of such defects is of the order of 40 nm; iii) the regrowth rate is impurity dependent: a factor two exists between the faste
Temperature Dependence of Ion Assisted Epitaxial Growth of Chemical Vapor Deposited Si Layers
Authors: Ferla A. La , Rimini E. , Spinella C. , Ferla G. 
Published: March 2011

ABSTRACTThin layers of Si were chemical vapor deposited onto as - received p-type <100> Si wafers and implanted with 80 KeV of As or Ge to a fluence of 1 × 1015 /cm2. Irradiation at 450°C with 600 KeV Kr++ ions causes the epitaxial growth of the entire deposited and amorphized Si layer. At lower irradiation temperatures the regrowth rate of the deposited layers is substantially reduced with respect that of the implanted amorphous layers. The presence of As enhances the regrowth rate of a factor 2.5. The results are explained qualitatively in terms of a dynamical bond breaking of SiO2, and of a dopant influence on the migration energy of the defects responsible for the growth.
Solid Phase Epitaxial Regrowth of Microcrystalline Si Films on a (100) Si Substrate
Authors: Roorda S. , Saito S. , Sinke W. C. 
Published: March 2011

ABSTRACTMicrocrystalline Si, as produced by explosive crystallization of an amorphous Si layer on (100) Si, shows a two-stage annealing behaviour. Initially, solid phase epitaxial regrowth occurs very rapidly at temperatures at, or above 800°C. After a few seconds, the regrowth rate slows down to the value typical for alignment of poly-Si. Solid phase epitaxial regrowth of microcrystalline Si is suggested to be strongly dependent on grain size and structure.
Recrystallization Characteristics of Amorphous Si
Authors: Herring Rodney A. , Fiore Eric M. 
Published: March 2011

ABSTRACTThe microstructure of high-energy (0.5–6.0 MEV) As-ion implanted Si and rapid thermal annnealed (RTA'd) Si has been studied by transmission electron microscopy (TEM). The implantations formed buried amorphous layers that recrystallized during RTA at different temperatures and became either single crystal or polycrystalline depending on their implation energy and fluence. At energies > 2.5 MeV and fluences < 1015cm−2, recrystallization occurred below 400°C and regowth was single crystal. At an energy of 6 MeV and fluence of 5 × 1015cm−2recrystallization occurred above 600°C and regrowth was polycrystalline. When the implantation energy and fluence were reduced to 0.5 MeV and 2 × 1014cm−2, respectively, recrystallization occurred above 600°C and regrowth was polycrystalline. The above results are explained by both the formation mechanisms of amorphous Si resulting from ion implantation and the structural order of a-Si.
On the Role of Interfacial Defect Sites During Solid Phase Epitaxial Regrowth of Implantation Amorphized Silicon
Authors: Adekoya W. O. , Hage-Ali M. , Muller J. C. , Siffert P. 
Published: March 2011

ABSTRACTWe have studied the solid phase epitaxial regrowth (SPER) of implantation (31P+11B+ (73Ge+ preamorphized)) amorphized silicon in the temperature range 500–600°C induced by Rapid Thermal Annealing (RTA) using Rutherford Backscattering and channeling measurements (RBS). Our results show rate enhancements (≃ 3.5–6.5) of the velocities of regrowth in all studied cases with respect to literature-reported values for furnace-induced SPER. Also, the ratio VB/VP (velocity of regrowth in the presence of boron with respect to phosphorus) gives a value of approximately 3 in both RTA and furnace-induced kinetics. These results are explained by a model which takes into account the role of electrically-active interfacial defect sites during SPER.
Supercooling of Silicon and Germanium after Laser Melting
Authors: Stiffler S. R. , Thompson Michael O. , Peercy P. S. 
Published: March 2011

ABSTRACTFollowing pulsed laser melting, supercoolings of 505 K in Si and 430 K in Ge were observed prior to bulk nucleation. These large supercoolings are obtained because of the extremely high thermal quench which follows laser irradiation. Nucleation rates were estimated to be ∼1029 events/m3/s. Assuming that homogeneous nucleation was achieved, surface energies are estimated to be 0.34 J/m2 for Si and 0.24 J/m2 for Ge. These results are in reasonable agreement with traditional homogeneous nucleation experiments sensitive to rates of only ∼1010 events/m3/s. This laser melting technique is applicable to nucleation studies in a wide variety of materials.
Elastic Instability During Amorphization of Internetallic Compounds by Charged-Particle Beams
Authors: Okamoto P. R. , Rehn L. E. , Pearson J. , Bhadra R. , Grinsditch M. 
Published: March 2011

ABSTRACTTransmission electron microscopy (TEN) and Brillouin scattering methods were used to determine the lattice dilatation and shear elastic constant as a function of the degree of long-range order during room temperature irradiation of Zr3Al with 1.0-MeV Kr+. The results indicate that the onset of amorphization in Zr3Al is triggered by an elastic shear instability, and that the instability is directly related to the volume dilatation associated with the destruction of long-range order. It is also shown that the volume dependence of the shear elastic constant associated with radiation-induced disordering and amorphization is virtually identical to that associated with the heating to melting of many metals.
The Projectile Mass Dependence of the Amorphization Process and the Critical Temperature in the Ion Irradiated CuTi
Authors: Koike J. , Okamoto P. R. , Meshii M. 
Published: March 2011

ABSTRACTCuTi was irradiated with 1MeV Ne+ and Kr+ at various temperatures in the Argonne-HVEM interfaced to a tandem accelerator. The integrated intensity of diffuse ring was measured by a microdensitometer and analyzed by Gibbons model for the dose dependence of the amorphous volume. The results indicate that the direct amorphization occurs in a single damage zone with Kr+, but the overlapping of three damage zones is necessary with Ne+. The critical temperature for amorphization was 401±22K for Ne+ and 543±20K for Kr+, respectively. With Kr+, the critical temperature was nearly equal to the thermal crystallization temperature of an amorphous zone embedded in the crystalline matrix. Using the present observations, the relation between the amorphization process and the critical temperature is discussed.
Application of Onsager's Reciprocity Relations to Alloy Solidification
Authors: Kaplan Theodore , Aziz M. J. , Gray L. J. 
Published: March 2011

ABSTRACTA requirement of any theory for the kinetics of interface motion during a phase transformation is that the force law which relates fluxes to thermodynamic forces satisfies Onsager's reciprocity relations. In this paper we show how to apply Onsager's relations to a phase transformation mediated by a moving interface in a two-component system. We use the result to evaluate two proposed models for interface motion during alloy solidification.
Excimer Laser Etching of Cupric Oxide
Authors: Veen G. N. A. van , Vrijmoeth W. , Baller T. S. , Dieleman J. 
Published: March 2011

ABSTRACTPolycrystalline CuO samples are irradiated in UHV by excimer laser pulses at 308nm. Mass spectrometry combined with time-of-flight measurements is used to determine the composition of the desorbing particles and the desorption mechanisms. Additional information is provided by Scanning-Electron-Microscopy of the etched surfaces. At fluences below 1.8 J cm−2 the products Cu, O and O2 are desorbed by a purely thermal mechanism at temperatures up to 6000 K and a copper rich surface mask is formed. At higher power densities an additional ablative contribution is monitored which increases with power density, and much less surface area is covered by a Cu-rich mask.
Key Issues Related to the Self-Aligned Formation of CoSi2 in a Salicide Process
Authors: Hove L. Van Den , Wolters R. , Geyselaers M. , Keersmaecker R. De , Declerck G. 
Published: March 2011

ABSTRACTThe self-alignment of the Co-Si interaction at the edge of a Si-SiO2 transition has previously been ascribed to the fact that Co is the main moving species during silicide formation. However, the reactions in the Co-Si system are more complex. The phenomena of lateral silicidation and encroachment are therefore investigated at various stages of the Co/Si reaction using samples starting either from sputtered Co layers or from cosputtered Co-Si multilayers with varying average stoichiometries. The mechanisms resulting in the absence of lateral silicidation are clarified.
Initial Stages of Silicon Growth on the (100) Surface of Silicon By Localized Laser Cvd
Authors: Kotecki David E. , Herman Irving P. 
Published: March 2011

ABSTRACTThis paper reports initial results of an experimental study of the early stages of silicon thin film growth on well prepared (100) c-Si surfaces by pyrolytic deposition from silane (SiH4) during localized laser chemical vapor deposition (LLCVD). The rate of silicon thin film growth during low pressure (< 10 Torr) deposition using tightly focussed laser beams (514.5 nm, ∼ 2.5 μm FWHM) is characterized and is shown to be much slower than expected based on the previously measured silane decomposition rate. Hybrid-heating experiments, in which laser heating induces a slight temperature increase on a uniformly heated substrate in the presence of silane gas, shows that growth is inhibited within the laser irradiation region. This result suggests that a nonpyrolytic mechanism contributes to silicon growth in laser CVD. Possible explanations for this nonpyrolytic growth mechanism are discussed.
Surface Chemical Reactions in the Mocvd of Aluminum Films
Authors: Bent Brian E. , Nuzzo Ralph G. , Dubois Lawrence H. 
Published: March 2011

ABSTRACTWe have studied the deposition of aluminum films by triisobutylaluminum (TIBA) pyrolysis on clean and oxidized Si(lll) (7×7), Si(100) (2×1), and an evaporated aluminum film on silicon. On all of the silicon surfaces, HBA has a very low reaction probability (<0.01). On aluminum, the reaction probability is much higher, and the rate of steady state aluminum deposition is limited by β-hydride elimination from surface-bound isobutyl species to give isobutene and hydrogen. In the steady state deposition of aluminum on top of silicon, gas phase silanes such as isobutyl- and diisobutylsilane are also evolved. This clearly indicates that hydrogen and alkyl ligand transfer from aluminum to silicon (which has diffused up through the growing aluminum film) can occur. We have also found that alkyl species generated on aluminum surfaces by. the adsorption of alkyl iodides have surface chemistries analogous to the aluminum alkyl ligands.
Surface Chemical Modification for Via-Hole Filling Using Tri-Isobutylaluminum Chemical Vapor Deposition
Authors: Fleming C. G. , Blonder G. E. , Higashi G. S. 
Published: March 2011

ABSTRACTTri-isobutylaluminum decomposition occurs preferentially on aluminum rather than silicon oxide surfaces. This preference might be exploited to fill via holes for multi-level integrated circuit metallizations. Initially a KrF excimer laser (248 nm) was used to sensitize aluminum pads in the base of the via holes. However, depending on the chemical treatment of the surface, it was discovered that laser enhanced activation was not required to obtain nucleation. At 240”C spontaneous aluminum growth can be made to occur exclusively in the via holes simply by utilizing appropriate cleaning methods. This technique was used successfully to fill via holes 1 μπι in diameter and 0.7 μπι deep with aluminum plugs. Selectivity is excellent, but chamber contamination can result in random nucleation. Technical problems still to be over come include grain growth morphology, 100 % via hole activation and better control of nucleation selectivity.
Al/Si Interface Characteristics Formed by Partially Ionized Beam Deposition at 2.5Kv
Authors: Wong J. , Lam C. , Lu T.-M. 
Published: March 2011

ABSTRACTPartially ionized beam (PIB) deposition technique was used to deposit Al thin film on Si(n) substrate. The fabricated Schottky diodes showed an anomalous C-V characteristics for the Al films deposited with a bias potential equal to 2.5kV. The 1/C2 vs. V plot showed a drastic decrease in the slope as compared to the diodes deposited without the bias potential. Further measurements showed a frequency dependence in the C-V characteristics. This anomalous C-V characteristics can be explained by the formation of a p-n junction diode underneath the Si surface. A model of self-ion implantation which explains the formation of this surface p-layer on the Si(n) substrate is proposed and tested.
Laser-Stimulated Noble Metal Deposition From Gaseous and Condensed Acetylacetonates. Photoreactions in the Supersonic Jet and Above Silicon
Authors: Heidberg Joachim , Daghighi-Ruhi Rahman , Von Weyssenhoff Hanns , Habekost Achim 
Published: March 2011

ABSTRACTLaser-stimulated deposition from the acetylacetonates of Pt and Ir has been found to take place on silicon surfaces. The gas phase photoreactions have been observed in a supersonic free jet TOF mass spectrometer and above silicon. The bare metal ions and metal cluster ions are formed from the complexes in the gas by multiphoton excitation. On the substrates deposits are detected by microprobe analysis with a metal content higher than 95 %.
Also from condensed complexes laser-induced metal deposition, and as competitive process photodesorption, takes place.
Laser Induced Forward Transfer
Authors: Baseman R.J. , Gupta A. , Sausa R.C. , Progler C. 
Published: March 2011

ABSTRACTThe laser induced forward transfer (LIFT) technique employs a pulsed laser to transfer material, originally precoated as a thin film on a transparent support, from that support onto a selected target substrate. LIFT has been used to deposit a variety of thin films, thick films through the repetitive transfer of thin films, multilayer structures through the transfer of appropriately layered precoated films, and metal silicon alloys.
An Analysis of the Effect of System Variables on the Quality of Thin Films and Powders Produced by Laser-Breakdown Chemical Vapor Deposition
Authors: Joyce E.L. , Jervis T.R. 
Published: March 2011

ABSTRACTA gas phase process for large area depositions on an ambient temperature substrate using laser-induced dielectric breakdown of gas phase precursors has recently been developed.1 Deposits of nickel alloys show excellent grain refinement (<10 nm) and metastable phase incorporation due to rapid quenching from the gas phase. Particle size distribution and compositional variance within the deposited films have been studied using electron microscopy and electron diffraction. Kinetic expressions to explain homogeneous gas phase nucleation and growth of the deposited materials have been developed in an effort to better understand this process. The effect of system variables on film and powder grain sizes has been studied. This analysis gives insight into the fluid flow/heat transfer patterns involved in the system and their effect on the final deposited material. The effect of system pressure, gas phase composition, and laser pulse energy, on particle size, surface area coverage, and deposition thickness are discussed.
Two-Photon Absorption Cross Section for Silane Under Pulsed Arf (193 nm) Excimer Laser Irradiation
Authors: Fuchs C. , Boch E. , Fogarassy E. , Aka B. , Siffert P. 
Published: March 2011

ABSTRACTWe have determined for the first time, the two-photon absorption cross-section of silane at 193 nm, by measuring directly the fraction of incident light absorbed in the gas phase during the irradiation with a pulsed ArF excimer laser.
Deposition of Amorphous Carbon Films by Laser Induced CVD
Authors: Tachibana H. , Nakaue A. , Kavate Y. 
Published: March 2011

ABSTRACTAmorphous carbon (a-C) films were prepared by photodissociation of C2H3Cl or CCl4 gas using a pulsed ArF excimer laser (193nm). An increase in the substrate teiperature decreased the deposition rate. For C2H3Cl4 the maximum deposition rate of 10Å/min was attained at a partial pressure of 0.1 Torr and room temperature. In contrast, for CCl4, the maximum deposition rate of 10Å/Min was obtained at a partial pressure of 3 Torr and room temperature. This difference may be attributed to the different absorption cross sections for the two gases. The structural and mechanical properties were leasured. An Auger analysis showed the chlorine content in the a-C film deposited at room temperature to be 1% for C2H3Cl and 8% for CCl4. The Mohs hardnesses of the a-C filis deposited at room teiperature were 7 and 2 for C2H3Cl and CCl4, respectively. It was concluded that both sp2 and sp3 bonds existed between neighboring C atoms at low temperatures, whereas SP2 bond was predominant at temperatures higher than 300°C.
Multispectral Spectroscopic Ellipsometry-A New Tool for In Situ Surface Analysis
Authors: Ferrjeu F. , Stehle J.L. , Bernoux F. , Thomas O. 
Published: March 2011

ABSTRACTSpectroscopie ellipsometry is a non-destructive tool for physical characterization without prior preparation of materials.Real time, in-situ measurements can be applied to analyze surface problems, to optimize thin film processing and even to monitor epitaxial growth or thin film deposition. Spectroscopie Eilipsometers built by SOPRA are described. A new instrument using Optical Multi-channel Analysis,(OMA), with a spectral range from 1.1 ev up to 4.8 ev which gives up to 11 ellipsometry spectra per second has been developed. Applications using Spectroscopie Ellipsometry are also discussed .
Laser-Induced Surface Modification and Etching of Materials
Authors: Bauerle D. , Eyett M. , Kolzer U. , Kullmer R. , Mogyorosi P. , Piglmayer K. 
Published: March 2011

ABSTRACTLaser-induced surface reduction and ablation of piezoelectric oxides is described for the examples of BaTi03 and LiNb03.The microscopic mechanisms involved in the laser-induced etching of single-crystal (100) Si in Cl2 atmosphere are investigated for the regime of low laser powers.
Schottky Contact Characterization of Thin, Excimer Laser Grown Gaas Oxides
Authors: Schmidt M.T. , Yu C.F. , Podlesnik D.V. , Yang E.S. , Osgood R.M. 
Published: March 2011

ABSTRACTThin GaAs-oxide layers have been formed on GaAs (100) surfaces using deep UV light to enhance the oxidation reactions. Two different oxidation reactions were compared by using UV light of wavelengths below and above the O2 dissociation limit, viz, 248 nm and 193 nm respectively. For the light above the O2 dissociation limit which causes ozone formation, oxides formed by direct surface illumination were compared to oxides formed by illumination parallel to the GaAs surface. Metal contacts were deposited in situ to study the effect of the various thin oxides on the Schottky barrier height of contacts to GaAs.