bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic Roughening of Interfaces and Mixing in Alloys Under Shear or Irradiation
Authors: Bellon P. , Partyka P. 
Published: April 2011

AbstractBoth irradiation and plastic deformation can induce the stabilization of non-equilibrium phases in alloys. A simple kinetic atomistic model is used for describing these two situations, when the external forcing is acting in competition with thermally activated diffusion. Monte Carlo simulations are performed on alloys with positive heats of mixing. Both situations share common features : random solid solutions are stabilized at high enough forcing intensity (i.e. irradiation flux or shearing rate), while at moderate forcing intensities interfaces exhibit kinetic roughening. However, major differences are observed : alloys under irradiation undergo dynamical transitions between steady-states, such as a dynamical roughening transition at interfaces and a precipitation-dissolution transition in the bulk ; in alloys under shear such transitions are not observed ; instead the steady-state microstructure of a two-phase alloy is continuously refined on increasing the shearing rate. These differences originate from the size of the perturbation induced by the external forcing : the perturbation is of microscopic size for alloys under irradiation, while it is of macroscopic size for alloys under shear. Results obtained for the shearing case provide a rationalization scheme of ball milling experiments showing chemical mixing of immiscible elements. The fact that such systems consist of nanograins should also contribute to prevent the existence of 1st order phase transitions on varying the milling conditions.
Nanosized Metallic Sn Precipitates in Si, Formed Upon Ion Implantation
Authors: Barancira T. , De Wachter J. , Milants K. , Verheyden J. , Deweerd W. , Odeurs J. , Pattyn H. 
Published: April 2011

AbstractIn this work we firstly established the optimal conditions to preferentially form nanosized β-Sn inclusions from a supersaturated solid solution of Sn in Si, formed by a high dose ion implantation. Afterwards we tried to elucidate the origin of the strongly enhanced recoilless fraction of Sn nuclei inside these precipitates, thereby making a link to the observed shift in isomer shift value. This is tentatively interpreted in terms of a local compression of the inclusion to about 200 kbar.
Formation of Epitaxial CoSi2 Layers Grown from the Interaction of Co/Ti Bilayers with Si <100> Substrates
Authors: Cardenas J. , Zhang S.-L. , Svensson B. G. , Petersson C. S. 
Published: April 2011

AbstractThe redistribution of titanium during the growth of epitaxial CoSi2 from the reaction of Co(20nm)/Ti(lOnm)/Si<100> structures has been investigated. The concentration of Ti in the CoSi2 layers versus annealing temperature has been determined. Emphasis is placed on the formation of inhomogeneities in the epitaxial CoSi2 layers, and the role of Ti with respect to the thermal stability of the layers. The fundamental mechanism for the development of inhomogeneities in the epitaxial CoSi2 layers will be discussed.
Phase Formation Between Codeposited Co-Ta Thin Film and Single Crystal Silicon Substrate
Authors: Riskin G. , Pelleg J. , Talianker M. 
Published: April 2011

AbstractA combination of near-noble and refractory metal silicides was considered for shallow contacts to silicon in VLSI circuits [1]. The objective of the present work is to investigate formation of phases between codeposited Co-Ta film, of 150 nm thickness, and n-type silicon substrates of (100) or (111) orientation. Characterization of the specimens annealed in the temperature range of 600–1100°C was done by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that in addition to the silicide phases of Co and Ta, the intermetallic compound Co2 Ta was also formed. Co2 Ta appears only in the lower temperature range of about 600–800°C. At temperatures of 900–1100°C only the silicon rich phases were present. These are the low resistivity phases useful for devices. No ternary phases have been observed. Silicide formation occurs at a faster rate on (111) oriented silicon substrates.
Reaction of Amorphous Silicon with Cobalt and Nickel Silicides Before Disilicide Formation
Authors: Maa Jer-Shen , Hsu Sheng Teng 
Published: April 2011

AbstractA method is introduced to reduce substrate Si consumption of the salicide process by supplying extra Si from an amorphous Si film. Si is introduced into cobalt silicide and nickel silicide at the time when the silicide is converted into the disilicide phase. The reaction rate with amorphous Si is higher than that with single crystal Si if the amorphous Si has a low oxygen content.
A Low Temperature Single-Step RTA Process to form Ultrathin CoSi2 for Mosfet Applications
Authors: Sherony Melanie J. , Sriram T. S. , England Craig , Pelillo Aldo , Harris William C. , Miller Stephen J. , Bill Steven A. , Yang Isabel Y. , Wei Andy , Antoniadis Dimitri A. 
Published: April 2011

AbstractA single-step, low temperature self-aligned CoSi2 process using Ti/Co source material has been developed for use in extreme submicrometer MOSFET applications. Ultra-thin CoSi2 films (∼ 20 nm) were obtained from a single-step RTA anneal at 550°C for 30 sec using Ti/Co source material on patterned n+ implanted (100) Si. X-ray diffraction was used to verify CoSi2 formation. Highresolution SEM and TEM examination showed the silicide to be microstructurally smooth and the devices showed no lateral growth of the silicide at the polysilicon spacer edge. Some voiding and lateral overgrowth was observed at the LOCOS isolation edge and this effect was exacerbated at higher anneal temperatures. This single-step low temperature CoSi2 process is a promising technology for deep-submicron MOSFET applications.
Application of Cobalt Salicide in Sub-Quarter Micron Ulsi
Authors: Bai G. , Stivers A. 
Published: April 2011

AbstractA thin Ti-siuicide film is widely used today as the low resistance shunt in a semiconductor chip. As the feature size in the chip shrinks to sub-quarter micron, the thin Ti-silicide film formed on such narrow lines transforms from C49 to C54 at increasing temperatures and agglomerates at decreasing temperatures, closing the process window for Ti-salicide process. In contrast, low resistivity Co-silicide thin films can be formed on narrow lines below the agglomeration temperature. In addition, an epitaxial CoSi2 with a flat interface can be formed in source/drain areas, enabling the formation of very shallow junctions with low leakage current. Experimental results on formation of silicides from Co/Ti bilayers and thermal stability of the CoSi2 films will be presented, with special emphasis on the sheet resistance of the silicide film versus poly-line width down to 0.15 umn. Interaction between dopants and silicide films will also be discussed.
Tungsten Silicide Films Based on Dichlorosilane Chemistry for sub 0.5 Micron Applications
Authors: Ozkan Cengiz S. , Moinpour Mansour 
Published: April 2011

AbstractCVD WSix, films have found widespread use as ultra thin gate, wordline and bitline interconnects due to the lower resistance that polycide offers. For submicron technologies, WSix films based on the monosilane chemistry shows limitations due to the incorporation of high concentrations of Fluorine ions and poor step coverage. Recent work has shown that, WSix films based on the dichlorosilane (DCS) chemistry minimizes these problems. One of the major issues in DCS WSix films is the in-depth compositional non uniformity, especially those deposited on poly-Si substrates. The formation of a W-rich region at the WSix/poly-Si interface can cause localized stresses which can result in cracking and adhesion problems. In this paper, we report the composition and structure of DCS WSix, films deposited on undoped, doped and in situ doped poly-Si and oxide substrates. We have investigated the effect of different processing conditions on Si/W uniformity and the formation of W-rich and Si-rich interfaces, and the role of the nucleation step in modulating the Si/W ratio at the WSix/poly-Si interface. The impact of a Si-rich region at the WSix/poly-Si interface on silicide film properties has also been explored. RBS measurements were used to determine the composition profile through the depth of the film and Si/W uniformity in terms of Si-rich and W-rich interfaces. SIMS measurements were used to determine the impurity content in the silicide film and at the film/substrate interface.
GeSi Infrared Detectors Using Selective Deposition
Authors: Strong R. , Greve D. W. , Weeks M. M. 
Published: April 2011

AbstractHeterojunction p++ GeSi / Si internal photoemission (HIP) detectors deposited by ultra high vacuum chemical vapor deposition (UHV/CVD) were investigated as alternatives to silicide Schottky-barrier type detectors for infrared focal plane arrays. HIP structures were grown using SiH4, GeH4, and B2H6 source gases on (100) p- Si substrates patterned with thermal oxide windows. Selective epitaxy was maintained over a range of boron concentrations (6×1019 – 6.5×1020 cm-3) and Ge fractions (0.38–0.50), and a maximum selective thickness of ~300Å was determined for silicon growth at 550°C. These structures were fabricated into IR detectors using techniques compatible with standard Si focal plane array processing technology. Photoresponse data were analyzed according to the modified Fowler equation, indicating cut-off wavelengths of 5–12 (μm) and Cl values of 8–21 (%/eV) depending on sample parameters. I(V) characteristics were also measured at various temperatures, yielding electrical barrier heights consistent with optical measurements.
Heteroepitaxy of CoSi2 on Patterned Si(100) Substrates
Authors: Karpenko O. P. , Eaglesham D. J. , Yalisove S. M. 
Published: April 2011

AbstractThis study has addressed the effect of starting surface topography on the nucleation and growth of epitaxial siicide layers. CoSi2 layers were grown via the template technique on one-dimensionally patterned Si (100) substrates. These substrates contained mesa stripes, running parallel to Si[011], and exhibited either smoothly varying sinusoidal profiles, or a number of well defined Si Ihkl) facets. Conventional plan view and high resolution cross section transmission electron microscopy were used to analyze the films grown on these substrates. The orientation and morphology of the CoSi2 grains depend on the angle (θ), between the CoSi2 / Si interface normal and Si (100). High quality (100) oriented CoSi2 grew on the tops and bottoms of mesa structures, where θ < 5°, and formed atomically sharp interfaces with the substrate. In contrast, CoSi2 (110) and CoSi2 (221 ) grains nucleated along the sidewalls of the mesa structures. The CoSi2 (110) grains formed rough interfaces with the substrate and were terminated by regions of step bunching at the grain boundary / substrate triple points. CoSi2 (110) grains were most highly concentrated in regions where θ varied from 5° to 12°. Similarly, the CoSi2 (221 ) grains formed faceted (111) b-type silicide / substrate interfaces, and were most highly concentrated in regions where θ > 10°. These data suggest that double height steps, step bunches and facets on the substrate are related to the nucleation of misoriented silicide grains.
New Epitaxially Stabilized Silicide Phases
Authors: Goncalves-Conto S. , Müller E. , Schmidt K. , Von Känel H. 
Published: April 2011

AbstractA new epitaxial CoSi2 phase has been synthesized on Si(111) by molecular beam epitaxy (MBE) at room temperature (RT). Structural investigations revealed, that films grown onto an ultrathin CoSi2 template crystallize with the CsC1 structure with 50% vacancies on the cation lattice. The same is true for codeposited films nucleating from the amorphous phase at very low annealing temperatures (100–200 °C). Upon annealing a gradual transition to the stable bulk phase with the CaF2 structure takes place. For films grown onto a template, some grains of (CsCl)Co0.5Si remain stable up to at least 550 °C, while the films grown without a template are fully transformed.
Structural Characterization of Ion Beam Synthesized Epitaxial ErSi2-x Layers
Authors: Bender H. , Wu M. F. , Vantomme A. , Pattyn H. , Langouche G. 
Published: April 2011

AbstractThe results are discussed of the characterization by means of TEM, RBS and XRD of ErSi2-x layers prepared by ion beam synthesis on (111) silicon. It will be shown that high quality (buried) layers can be prepared by channelled implantation of the erbium, whereas unchannelled implantation leads to discontinuous polycrystalline surface layers. The epitaxial growth and vacancy ordering in the silicide are discussed.
Rapid Thermal Annealing of Tungsten Silicide Films
Authors: Fabricius A. , Nennewitz O. , Spieβ L. , Cimalla V. , Pezoldt J. 
Published: April 2011

AbstractTungsten / silicon multisandwich layers were deposited by DC magnetron sputtering on silicon and silicon oxide substrates. After the deposition the samples were annealed by rapid thermal annealing at different temperatures under H2 atmosphere. X-ray diffraction measurements were carried out to determine the crystal structure of the obtained silicide layers. To estimate the grain size and the relative lattice strain in dependence on the annealing temperature from the X-ray profile the deconvolution method of Lagrange was used. To characterize the electrical properties the specific resistance was measured by a linear four-point method. The best specific resistance measured was approximately 17 μΩcm for the sample on silicon substrate annealed at 1195 °C for 20 seconds. Rutherford Backscattering Spectroscopy measurements were carried out to obtain the stoichiometric depth profile.
Evaluation of Mechanical Properties of Sputtered Ceramic Films from Nanoindentation and Wafer Curvature Techniques
Authors: Inturi Rama B. , Barnard John A. 
Published: April 2011

AbstractTiB2, MoSi2, Si3N4 and Ta4N ceramic films were magnetron sputtered on oxidized Si and Coming 7059 glass substrates at ambient temperature. X-ray diffraction studies indicate that the structure of the films is very different on the two substrates, even though the surface of both substrates is amorphous. The hardness and elastic modulii of the films on oxidized Si are slightly higher than those of the films deposited on Coming glass substrate, even at indentation depths where substrate effects are considered to be negligible. A substantial increase in hardness (5–10 GPa) was observed for TiB2 films, when compared to the properties of bulk stoichiometric TiB2. Stress- temperature diagrams determined from room temperature to 250 C indicate that all the films prepared in this study display a pure elastic behavior in that temperature range.
Microstructure and Mechanical Properties of Plasma Assisted CVD Ti(C,N) Films as a Function of Carbon Content
Authors: Xu K. W. , Sun H. L. , Hu N. S. , Hendrix B. C. 
Published: April 2011

AbstractThe results show that unlike those made by physical vapour deposition, Ti(C,N) coatings made by plasma assisted chemical vapour deposition are composed of two phases, TiN and TiC. With the formation of two phases, the columnar structure vanishes gradually and the crystal size becomes small. The carbon content is the dominant controlling factor for a linear increase in microhardness of the coatings, but the residual macrostress and the adhesive strength evaluated under cyclic contact conditions are dependent to a great extent on the percentage of the two phases. There is an intermediate carbon content for the present Ti(C,N) coatings which yields a fine mixed microstructure and optimum mechanical properties.
Growth of Polycrystalline Silicon Films at Low Temperature by Plasma Enhanced Chemical Vapor Deposition
Authors: Hatanaka Y. , Jayatissa A. H. , Ishikawa K. , Nakanishi Y. 
Published: April 2011

AbstractPolycrystalline silicon (poly-Si) films are of great interest in the field of TFT fabrication for active matrix liquid crystal display(AM-LCD) applications. Low temperature depositions below 500 °C are necessary for using a glass substrate for the application to large area devices such as display devices. We investigated poly-Si growth at low temperature by plasma enhanced chemical vapor deposition (PECVD). Cathode deposition is used in which substrates are mounted on the powered electrode and a mesh electrode is attached on the cathode for protecting the growing surface from ion impacts. It is found that poly-Si films can be deposited in the wide range of SiH4 concentration even at 100%, and a high deposition rate of 35nm/min has been realized. This investigation gives highly promising results for poly-Si growth technology at low temperature.
Texture Maps for Orientation Evolution During Grain Growth in Thin Films
Authors: Seel Steven C. , Carel Roland , Thompson Carl V. 
Published: April 2011

AbstractOrientation selective grain growth in thin films arises due to anisotropy in materials properties. For continuous thin films, there are at least two orientation dependent driving forces for grain growth: (i) surface and interface energy anisotropy; (ii) strain energy anisotropy (both elastic and plastic). In fcc metals, the preferred growth of grains with (111) texture occurs due to their low surface and interface energy. Stresses in thin films arise during deposition and as a result of post-deposition annealing. A texture dependence of strain energy density arises in biaxially strained thin films due to anisotropy of elastic properties and/or orientation-dependent yield stresses. For most fcc metals, the strain energy driving force promotes the growth of (001) grains due to minimization of the combined elastic and plastic strain energy. The magnitudes of the orientation dependent driving forces for grain growth depend on the characteristics and processing conditions of the film and substrate. We have performed grain growth experiments for Ag films on single crystal Ni on MgO; Ag films on plasma-enhanced chemical vapor deposited (PECVD) SiO2 on MgO; Ag films on oxidized Si; and Ni films on oxidized Si. The texture resulting from grain growth in films of different thicknesses and deposited at different temperatures were determined, and the results are presented in the form of texture maps. The texture which dominates as a result of grain growth can be understood through the use of texture maps and compares well with analytic models for texture development during grain growth in thin films.
Microstructural and Magnetotransport (EHE) Properties of Epitaxial τ-MnAl on (100)GaAs Substrates by Pulsed Laser Deposition
Authors: Rosier T. M. , He Y. , El-Masry N. A. 
Published: April 2011

AbstractWe report on the crystal quality and magnetotransport properties (EHE) of epitaxial (001) τ-MnA1/GaAs(100) grown by the laser ablation deposition technique. Films (10–30 nm thick) were grown by two methods: (1) ablating a τ-MnAl target, prepared in-house; (2) alternate deposition of ultra thin layers of Mn and Al (˜6 periods) followed by annealing at different temperatures. For both deposition approaches ultrathin coherent epitaxial τ-MnAl films have been grown at temperatures in the range 250–420°C that is below the ε-phase transformation temperature. Reflection high energy electron diffraction (RHEED) and high resolution transmission electron microscopy (HRTEM) were used to characterize the crystalline quality of the deposited films. The Extraordinary Hall Effect measurements (EHE) indicate that the deposited films are perpendicularly magnetized showing coercivity up to 6 kOe at room temperature. The epitaxial growth of thin film ferromagnetic materials on lattice matching semiconductor substrates offers the possibility of integrating magnetic and semiconducting devices.
Preferred Crystal Orientation and its Effect on the Magnetization Reversal Property of CoCrTa Thin Films
Authors: Yeh T. , Wang G. , Lin J. C. , Sivertsen J. M. 
Published: April 2011

AbstractCoCrTa thin films with c-axis predominatly oriented perpendicular to the plane of the film were obtained by sputter deposition on thin tantalum nitride underlayers with −75 volts substrate bias applied during the deposition of the film. The relationship between the distribution of c-axes preferred crystal orientation and magnetization reversal properties of the sputtered CoCrTa films was investigated. Higher coercivities are obtained for CoCrTa films having a more random crystal orientation distribution of hcp c-axes in polycrystal films, while lower coercivity is obtained for the highly oriented films. Such behavior may be attributed to the form of the induced local energy fluctuations associated with the crystal orientation distributions.
Using Principle of Virtual Motion and Galerkin Approximation to Analyze Surface Diffusion
Authors: Sun B. , Suo Z. , Cocks A. C. F. 
Published: April 2011

AbstractThis paper outlines the use of the Principle of Virtual Motion and the Galerkin approximation to analyze surface diffusion phenomena. Various ideas are illustrated with an analysis of the evolution of a fiber of bamboo-like grain structure.
Growth and Thermal Stability of Thin Niobium Overlayers on (0001) Sapphire Substrates
Authors: Wagner T. , Lorenz M. , Langjahr P. A. , Ruhle M. 
Published: April 2011

AbstractThin Nb films were deposited by MBE on (0001)α-Al2O3 in UHV. At a substrate temperature of 800°C, reflection high energy electron diffraction (RHEED) revealed that the film grew with the orientation relationship (planes of similar symmetry are parallel to each other): (0001)α-Al2O3 ‖ (111)Nb; [2110]α-Al2O3 ‖ [110]Nb. Investigations with conventional transmission electron. microscopy (CTEM) revealed that the film was not perfectly epitaxial after deposition. Small Nb grains with different orientations were embedded in the epitaxial Nb film. During annealing at temperatures well above the deposition temperature, secondary grain growth of the small embedded Nb grains occured, leading to a different epitaxial relationship between the Nb film and the sapphire: (0001)α-Al2O3 ‖ (110)Nb; [0110]α-Al2O3 ‖ [001]Nb.
Features of the Metal Nuclei Spatial Distribution on the Glassy Carbon Surface During the Receipt of Thin Films by Electrolysis
Authors: Arzhanova T. A. , Kovarsky N. Ya. , Radchenkova T. V. 
Published: April 2011

AbstractThe statistics of the distances among the nearest-neighbor nuclei developed at the initial stage of the electrolysis was analyzed using the example of the metal (Cu, Ag, Cd) electrocrystallization on the isotropic glassy carbon. It was confirmed that the most frequently met intemuclei distances tn that follow the progression equation tn = t1 · qn-1 with q≈1.4 form “structural spots” where they are located following each other in a strict sequence ti, t2 …. , tn,. It is found that the form of the “structural spots” is variable and the nuclei's density toward the border of the spot either is decreased or increased. The conditions of electrolysis under which the phenomenon of the nuclei statistically arranged order is not seen are also found.
Mechanisms of Hydrothermal Barium Titanate Thin Film Formation
Authors: Dogan F. , Sarikaya M. 
Published: April 2011

AbstractLow temperature synthesis of BaTiO3 thin films was performed under hydrothermal conditions below 80°C. Titanium metal, polycrystalline titanium oxide, and polystyrene (coated with a metallo-organic titanium precursor by a sol-gel process) were used as substrate materials. The reactions between the substrates and aqueous Ba(OH)2 solution took place at different time intervals from 10 minutes to 48 hours. The formation mechanisms of BaTiO3 was investigated by electron microscopy techniques during the reaction sequence. It is proposed that the nucleation and growth of crystalline BaTiO3 occur within an amorphous intermediate phase on Ti-metal and polystyrene substrates. However, thin film of BaTiO3 does not form on the surface of the sintered polycrystalline TiO2 under similar reaction conditions.