bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dopant Loss Origins of Low Energy Implanted Arsenic and Antimony for Ultra Shallow Junction Formation
Authors: Shibahara Kentaro , Furumoto Hiroaki , Egusa Kazuhiko , Koh Meishoku , Yokoyama Shin 
Published: April 2011

ABSTRACTWe have investigated the origins of sheet resistance increase in ultra shallow junctions formed by low energy As or Sb implantation. The increase is mainly attributed to dopant loss during annealing due to pileup of dopant at Si02/Si interface. This problem is common to As and Sb and will become more significant as the implantation energies are decreased. We found that the pileup can be classified into two stages from the time dependence of Sb SIMS depth profile .In the early stage of annealing the pileup is very fast and is probably related to the transport of the dopants due to solid phase epitaxial growth of an amorphized layer formed by the implantation. In the later stage the pileup is much slower and is considered to be governed by dopant diffusion.
Transient Enhanced Diffusion for Ultra Low Energy Boron, Phosphorus, and Arsenic Implantation in Silicon
Authors: Yu Ning , Jain Amitabh , Mercer Doug 
Published: April 2011

ABSTRACTThe SIA roadmap predicts that junction depths of 500 angstroms are required for CMOS technology nodes of 0.18 μm or beyond by the year 2001. There are several ultra-shallow junction doping techniques currently under investigation. These include beamline ion implantation, plasma immersion ion implantation, and gas immersion laser doping. This study was based on beamline ion implantation of B, P, and As into single-crystal Si wafers at 0.25-2 keV to doses of (2- 10)×1014 at./cm2 with minimized beam energy contamination. Rapid thermal annealing was applied to the implanted wafers at 1000-1050 °C for 10-15 sec at ramp rates of 35- 50 °C/s in a N2 ambient. Transient enhanced diffusion was observed for all three implant species. For example, the depth of 0.25 keV B measured by SIMS increases from 250 to 520 A at a concentration level of l×1017 at./cm3 upon RTA. To minimize the TED, several schemes of defect engineering were applied prior to low energy implantation, including pre-amorphization and implantation of other species. A comparison of TED for different implantation conditions is given with the aim of process development for minimizing TED. The impact of energy contamination on ultra shallow junctions is also addressed.
Atomistic Modeling of Point and Extended Defects in Crystalline Materials
Authors: Jaraiz Martin , Pelaz Lourdes , Rubio Emiliano , Barbolla Juan , Gilmer George H. , Eaglesham David J. , Gossmann Hans J. , Poate John M. 
Published: April 2011

ABSTRACTAtomistic process modeling, a kinetic Monte Carlo simulation technique, has the interest of being both conceptually simple and extremely powerful. Instead of reaction equations it is based on the definition of the interactions between individual atoms and defects. Those interactions can be derived either directly from molecular dynamics or first principles calculations, or from experiments. The limit to its use is set by the size dimensions it can handle, but the level of performance achieved by even workstations and PC's, together with the design of efficient simulation schemes, has revealed it as a good candidate for building the next generation of process simulators, as an extension of existing continuum modeling codes into the deep submicron size regime. Over the last few years it has provided a unique insight into the atomistic mechanisms of defect formation and dopant diffusion during ion implantation and annealing in silicon. Object-oriented programming can be very helpful in cutting software development time, but care has to be taken not to degrade performance in the critical inner calculation loops. We discuss these techniques and results with the help of a fast object-oriented atomistic simulator recently developed.
Boron Ted in Pre-Amorphised SI: Role of the A/C Interface
Authors: Mathiot D. , Bonafos C. , OMRI M. , Alquier D. , Martinez A. , Claverie A. 
Published: April 2011

ABSTRACTIn this paper we first review the main experimental results concerning boron diffusion in preamorphised silicon, focusing on the role played by the End Of Range defects. It is then shown that the application of the Ostwald ripening theory to the particular geometry of these defects permits to understand why and how they affect dopant diffusion. Contradictory experimental results can be reconciled if one considers that most of the diffusion enhancement occurs during the nucleation stage of the extended defects, and that the amorphous / crystalline interface is a perfect screen for the diffusion of the self-interstitials.
Wet And Dry Oxidation of Polycrystalline SixGe1-x Films
Authors: Hellberg P.-E. , Zhang S.-L. , d'Heurle F. M. , Petersson C. S. 
Published: April 2011

AbstractWet and dry oxidations of polycrystalline SixGe1-x, with various compositions have been studied at different temperatures. The growth rate of SiO2 is found to be enhanced by Ge, and the enhancement effect is more pronounced in H2O than in O2. A mathematical model, which assumes simultaneous oxidation of Si and Ge and reduction of GeO2 by free Si available at the growing-oxide/SixGe1-x interface, is found to give a quantitative description of the SiO2 growth during thermal oxidation of SixGe1-x. Kinetic parameters are extracted by comparing the model with experiments. The linear and parabolic rate constants for Si oxidation are determined on control Si (100) wafers and polycrystalline Si films. Simple expressions are used for the interdiffusion of Si and Ge in SixGe1-x. For wet oxidation, the activation energy for the reaction rate constant of Ge oxidation is found to be smaller than that of Si oxidation.
Evidence For Heterojunction Effects in Polycrystalline Si1-xGex Thin Film Transistors With Si Caps
Authors: Wang Albert W. , Saraswat Krishna C. 
Published: April 2011

AbstractPolycrystalline silicon-germanium (poly-Si1-xGex) thin film transistors (TFTs) werefabricated with and without Si interlayers (caps) to buffer the SiO2 gate dielectric and theSi1-xGex channel. Both low temperature processes (≤ 550 °C) compatible with glass for flat panel displays and high temperature processes were used. NMOS TFTs show dramatic performanceimprovements up to moderate (5 to 10 nm) interlayer thicknesses. In contrast, PMOS TFTs showonly small improvements at low interlayer thicknesses (< 5 nm), after which performancedeclines. Computer simulations using an effective medium model for polycrystalline materialssuggest that in addition to interface improvement, a pseudomorphic heterojunction is formedfrom the strained Si cap and unstrained poly-Si1-xGex channel with both conduction and valenceband offsets. These offsets play a significant role in inversion layer formation.
Photonic Crystals Based onMacroporous Silicon
Authors: Lehmann V. , Grüning U. , Birner A. 
Published: April 2011

AbstractThe formation of macropore arrays with high aspect ratios by electrochemical etching of n-type silicon in hydrofluoric acid is a well established technique. By using standard photolithograpy the geometry of the array can be controlled with high precision. This enables us to fabricate twodimensional photonic crystals for the infrared regime. The calculated photonic band structure of the crystal corresponds well with the transmission observed experimentally. Furthermore first defect structures like waveguides and cavities have been realized.
Fabrication Of Sub 30 Nanometer Sheets Of Single Crystalline Silicon
Authors: Flemitng J. G. 
Published: April 2011

AbstractA relatively simple technique for the fabrication of sub 30 rim thick sheets of perfect single crystalline silicon is described. The thinnest sheets formed were 15 nim thick. The width of the sheets is 300–1000 nmn and the length of the sheets can be tens of microns. The sheets are crystallographically well defined with the thin dimension being bound by atomically smooth {111} planes. The sheets are fabricated using a combination of reactive ion etching and wet KOH etching steps.
Band Alignment of Si1-xGex And Si1-x-y.GexCy Quantum Wells On Si (001)
Authors: Rowell N. L. , Williams R. L. , Aers G. C. , Lafontaine H. , Houghton D. C. , Brunner K. , Eberl K. , Schmidt O. , Winter W. 
Published: April 2011

AbstractRecent low-temperature photoluminescence (PL) studies will be discussed for coherent Si1-xGex. and Si1-xGexCy alloy multiple quantum wells on Si (001) substrates grown by either ultra-high vacuum chemical vapour deposition or solid source molecular beam epitaxy. An in-plane applied-stress technique will be described which removes systematically band edge degeneracies revealing the lower, PL-active CB. Applied-stress data taken with this technique at ultra-low excitation intensity proved intrinsic type II CB alignment in SiGe on Si (001). Apparent type I alignment observed at higher intensity will also be discussed. New applied stress PL results are presented for Si1-x-yGexCy quantum wells under various grown-in stress condition
Strong Deviation Of The Lattice Parameter In Si1-x-yGexCy Epilayers From Vegard's Rule
Authors: Stangl J. , Zerlauth S. , Schäffler F. , Bauer G. , Berti M. , Salvador D. De , Drigo A. V. , Romanato F. 
Published: April 2011

AbstractFrom the comparison of precise determinations of the Ge and C contents of a series of Si1-x-yGexCy epilayer samples (x < 0.18, y < 0.02) by Rutherford and resonant backscattering experiments and x-ray diffraction, the variation of the Si1-x-yGexCy lattice spacing as a function of C content is determined. A significant negative deviation from Vegard's rule is observed, in agreement with theoretical predictions by Kelires.
Evidence for Substitutional C, Ordering Effects and Interdiffusion in Epitaxial GE-C and GE-RICH GE-SI-C Alloys
Authors: Yang Bi-Ke , Weber W. H. , Krishnamurthy M. 
Published: April 2011

AbstractWe report on the epitaxial growth of Ge-C and Ge-Si-C alloys (C<10%) grown on Si(100) and Ge(100) substrates using low temperature (∼200°C) molecular beam epitaxy. Thin films (50–70 nm) were characterized in-situ by RHEED and ex-situ by transmission electron microscopy, xray diffraction, and Raman spectroscopy. The films were annealed at 750°C and 850°C in an Ar atmosphere to study interdiffusion effects.Raman spectroscopy of Ge-C on Ge indicates the existence of a Ge-C local mode at 530cm−1 and is direct evidence for the presence of substitutional C in Ge. The GeSiC alloys grown on Ge do not show the Ge-C local mode, consistent with preferential Si-C bonding. There is evidence for strain enhanced solubility of C based on a comparison of the substitutional C content in Ge-C films on Si (∼1 at %) and on Ge substrates (∼0.1 at %). Silicon interdiffusion in annealed Ge-C samples is strongly suppressed by the presence of C. A simple diffusion model is used to illustrate Si indiffusion in Ge.
Growth of GaN on Thin SI {111} Layers Bonded to SI {100} Substrates
Authors: Fleming J. G. , Han Jung 
Published: April 2011

AbstractWe have demonstrated the ability to bond thin layers of Si {111} onto either silicon dioxide or silicon nitride coated Si {100}. This was achieved using a “Smart-Cut” process. The integration of SiN required chemical mechanical polishing. The growth of GaN on a thin Si {111} on oxide on Si {100} stack was demonstrated.
Effect of Microstructure and Chemical Bonding on the Adhesion Strength of a Silicon/Polymer Interface for Microelectronic Packaging Applications
Authors: Pantelidis Dimitrios , Lee Hoo-Jeong , Bravman John C. 
Published: April 2011

AbstractInterface reinforcement brought about by addition of a γ-amino-propyl-triethoxy-silane (γ-APS) adhesion promoter layer between a silicon wafer and a spun-on benzocyclobutene polymer (BCB) is investigated. Combining cross-sectional TEM and XPS, crack growth is shown to occur along the γ-APS/BCB interface. Ion etching and in-situ XPS are further employed to study chain orientation and chemical bonding variations through the silane layer. A tendency of the amide group to orient away from the wafer is documented and Si-O-Si siloxane bonding at the γ- APS/SiO2 interface is hypothesized as an important mechanism for adhesion strength enhancement.
Mocvd-Preparation And In-Situ/Uhvanalysis Of Epitaxial Inp-Films
Authors: Hannappel T. , Visbeck S. , Knorr K. , Zorn M. , Willig F. 
Published: April 2011

AbstractSurface science analysis can be utilized for improving the preparation of hetero-interfaces. Epitaxial InP(100)-films were prepared with TBP (tertiarybutylphosphine) and TMin (trimethylindium) as precursors in a commercial MOCVD apparatus. With a new type of transfer system the sample is shifted from the MOCVD apparatus to a UHV chamber within 20 s. A description of the new transfer system is given. RAS (reflection anisotropy spectroscopy) is carried out in the MOCVD and UHV environments. It shows whether the InP(100) surface corresponds to the (2×1) or (2×4) reconstruction or whether it is oxidized. For the first time contamination-free transfer of the (2×1) reconstructed, P-rich InP(100) surface is achieved.
Growth And Characterization Of Amorphous Ain Thin Films By Reactive Magnetron Sputtering At Low Temperature
Authors: Gurumurugan K. , Chen Hong , Harp G. R. 
Published: April 2011

AbstractWe present the first report of the preparation and characterization of α-AIN films using reactive magnetron sputtering at cryogenic temperature. By comparison, analogous films grown at room temperature were polycrystalline. The films were characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Rutherford Backscattering Spectrometry (RBS), Infrared (IR) Spectroscopy and optical transmission. XRD studies on films grown at room temperature showed diffraction peaks corresponding to (100), (101), (102) and (210) planes. In contrast, no peaks were observed for AIN films formed at liquid nitrogen temperature confirming the amorphous nature of the films. Composition analysis using RBS showed the presence of Al and N in ˜1:1 stoichiometry. The films were highly transparent and the computed bandgaps of αand c-AIN films were 5.90 and 5.89 eV respectively. We also consider the possibilities of wet etching the AIN films in diluted KOH solution and the results are discussed.
Effects of CF4, Reactive ion Etching on Si-Doped Al0.2Ga0.8As
Authors: Ito Akira , Sakai Atsuyoshi , Tokuda Yutaka 
Published: April 2011

AbstractEffects of CF4 reactive ion etching on electrical characteristics of Si-doped Al0.2Ga0.8As layers were studied with capacitance-voltage and deep level transient spectroscopy measurements. Plasma exposure for about 30 s drastically degrades the electrical characteristics. Post-annealing at 360 °C for 20 s partially recovers the carrier concentrations. After the post-annealing, some electron traps were observed. Two of the traps show bi-stability. The concentrations of the two traps increase with forward bias temperature annealing and decrease with reverse bias temperature annealing.
Study of SI1−xGEx / SI / SI1−xGEx Heterostructures with abrupt interfaces for ultrahigh mobility FETS
Authors: Sugii N. , Nakagawa K. , Yamaguchi S. , Miyao M. 
Published: April 2011

AbstractWe grew Si1−x, Gex / Si / Si1−xGex heterostructures with abrupt interfaces for a high-speed device application. In order to eliminate the interface and the impurity scatterings, a two-stepsolid-phase epitaxy (SPE) was developed newly. This SPE can obtain an abrupt interface between the upper Si1−xGex. and the Si-channel layers as well as a sharp Sb-doping profile in the upper Si1−xGex layer. Single-step SPE growth of the Si1−xGex. layer including the Sb-doped layer caused solid state diffusion of Sb and made the doping-profile difficult to control. A two-step SPE, (that is, two independent SPE processes forming the Si1−xGex. and the Sb-doped layers), obtained a sharp Sb depth profile and high electrical activation in the Sb-doped Si1−xGex. layer. However, the number of modulation-doped carriers in the Si channel layer was small. Calculation of the carrier distribution between the channel and the doped layer suggests that the carrier density in the channel is low when the Sb-doping profile is extremely sharp; thus, precise control of the modulation-doped-carrier density by optimizing the thickness of the Sb-doped layer is crucial for operating modulation-doped field-effect transistors (MODFETs).
Surface Termination of the Ge(100) and Si(100) Surfaces by Using DHF Solution Dipping
Authors: Sakuraba M. , Matsuura T. , Murota J. 
Published: April 2011

AbstractSurface termination of Ge(100) and Si(100) was investigated after diluted HF (DHF) solution dipping. On the Ge(100) surface as picked up from DHF, Ge-hydride was observed only in the HF concentration (CHF) region above 10%. The adsorbed fluorine increased with increasing CHF, and the concentration reached around 1014 cm−2 at the CHF of 40-50%. In the case of the DHF dipped Si(100) surface, Si-hydride and hydrophobicity against both DHF and deionized water (DIW) were observed for all the conditions studied, while the fluorine concentration increased and saturated to about 1014 cm−2 in the CHF region above 15%. Hydrophobicity against DHF was observed in the CHF region of 10-30%, but degraded below 5% and above 30%. By transferring the DHF dipped Ge(100) into DIW, hydrophobicity appeared within a few seconds and then was degraded with increase of DIW dipping time. The degradation proceeded slower after dipped in higher concentration DHF. Corresponding to the degradation, it was observed that the total amount of the adsorbed fluoride was gradually decreasing, while the Ge-hydride coverage scarcely decreased. From these results, hydrophobicity of Ge(100) seems to be attributed not only to the hydrogen termination but also to the fluoride adsorption, which is much different from the case of Si(100).
First–Principles Investigation of the Ordered Si 4c compound
Authors: WINDL W. , SANKEY O. F. 
Published: April 2011

AbstractWe have performed intensive theoretical studies on the ordered Si 4C phase which has been proposed first by Riicker et al. [Phys. Rev. Lett.72, 3578 (1994)] and which recently has been reportedly synthesized by Kouvetakis et al. [Appl. Phys. Lett.72, 930(1998). We calculate structural parameters which are significantly different from experimental values, and an IR spectrum with a peak position very similar to their experiment but a much narrower width. We suggest that the experimental findings might be consistent with the assumption of a system of Si4C sections/crystallites and other Si–C structures embedded in a Si matrix.
Image Forces on 3D Dislocation Structures in Crystals of Finite Volume
Authors: El-Azab A. 
Published: April 2011

AbstractThe present work aims at studying the image stress and image Peach-Koehler force fields for three-dimensional dislocation configurations in a single crystal of finite volume. It is shown that the image stress field is significant within the entire crystal volume, and that the image Peach-Koehler force can be of the same order of magnitude as the direct interaction force calculated from the infinite domain solution. The results demonstrate that image stress gives rise to long-range interaction forces that are important in meso-scale dynamics of dislocation structures.
Characterizing and Modeling Plastic Strain Inhomogeneity in Thin Metallic Sheets
Authors: Li X. , Tong W. 
Published: April 2011

AbstractUsing a newly developed plastic strain measurement technique based on digital image correlation, surface plastic deformation of polycrystalline aluminum alloys in a thin sheet form has been experimentally characterized at a length scale comparable to that of the thickness of the aluminum sheets but much larger than the average size of individual grains. Both static and dynamic local straining patterns in these aluminum alloys have been observed and these strain patterns can not be simulated using the conventional plasticity models. The texture clustering of grains may contribute to the static local plastic strain patterns detected in an Al-Mg alloy. Two distinctive dynamic straining behaviors resulted from the dynamic strain aging of dislocations due to the alloying elements have been experimentally established for 5XXX and 6XXX alloys, respectively. First observation of dynamic strain inhomogeneity is also made in a sheet metal specimen deforming predominately in a plane strain state.
Characterization of Cast Metals with Probability Distribution Functions
Authors: Steinzig M. , Harlow F. H. 
Published: April 2011

AbstractCharacterization of microstructure using a probability distribution function (PDF) provides a means for extracting useful information about material properties. In the extension of classical PDF methods developed in our research, material characteristics are evolved by propagating an initial PDF through time, using growth laws derived from consideration of heat flow and species diffusion, constrained by the Gibbs-Thomson law. A model is described here that allows for nucleation, followed by growth of nominally spherical grains according to a stable or unstable growth law. Results are presented for the final average grain size as a function of cooling rate for various nucleation parameters. In particular we show that the model describes linear variation of final grain size with the inverse cube root of cooling rate. Within a subset of casting parameters, the stable-to-unstable manifests itself as a bimodal distribution of final grain size. Calculations with the model are described for the liquid to epsilon phase transition in a plutonium I weight percent gallium alloy.
Large Scale Molecular Dynamics Simulations of a Liquid Crystalline Droplet with Fast Multipole Implementations
Authors: Wang Zhiqiang , Lupo James , Patnaik Soumya S. , McKenney Alan , Pachter Ruth 
Published: April 2011

AbstractThe Fast Multipole Method (FMM) offers an efficient way (order O(N)) to handle long range electrostatic interactions, thus enabling more realistic molecular dynamics simulations of large molecular systems. The performance of the fast molecular dynamics (FMD) code, a parallel MD code being developed in our group, using the three-dimensional fast multipole method, shows a good speedup. The application to the full atomic-scale molecular dynamics simulation of a liquid crystalline droplet of 4-n-pentyl-4'-cyanobiphenyl (5CB) molecules, of size 35,872 atoms, shows strong surface effects on various orientational order parameters.
The Role of Cluster Size and Topology on the Ripening of Defect Aggregates in Crystalline Si
Authors: Magna Antonino La , Coffa Salvatore , Colombo Luciano 
Published: April 2011

AbstractWe present an ‘on lattice’ Monte Carlo study of defect clustering in a Si matrix. The simulations are based on local interaction models, which allows us to reliably include the energetics of defects obtained by tight binding molecular dynamic calculations. In particular the dependence of cluster stability and reactivity on cluster size and geometrical configuration is considered. Proper accelerated algorithms have been implemented in order to extend simulations to macroscopic time scales. Our simulations show that the stability of specific cluster configurations strongly affects the kinetic evolution of the defect ensemble.
Simulation of Dislocation Dynamics in the Continuum Limit
Authors: Schwarz K. W. 
Published: April 2011

AbstractPeach-Koehler theory is implemented to simulate the motion of three-dimensionally interacting dislocations, located on various glide planes and having any allowed Burgers vector. The self-interaction is regularized by a modified Brown procedure, which remains stable and loses accuracy in a well-controlled manner as atomic dimensions are approached. The method is illustrated by applying it to several problems involving interacting dislocations in an fcc slip system. The strong interaction of two dislocations on intersecting glide planes is investigated with a view towards developing a set of rules to describe the outcome of such interactions. The effect of Frank-Read sources in relaxing a strained layer are illustrated, both for sources on parallel and on intersecting glide planes.