bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mismatch and Misalignment at Interfaces Between Ag and Mn3O4 Studied With Hrtem
Authors: Kooi B. J. , Groen H. B. , De Hosson J.Th.M. 
Published: April 2011

ABSTRACTInternal oxidation of Ag-3at.%Mn resulted in Mn3O4 precipitates with a “parallel” topotaxy with the metal matrix and an octahedron shape due to {111} facets. Due to the tetragonali ty of Mn3O4, only a few planes and directions of Ag and Mn3O4 can be actual parallel. The precipitates exhibited a preference to align {111} planes parallel with the matrix for one pair of facets and then for another pair a tilt of 7.6° occurs which is relieved by ledges in Ag. The dislocation structure at these parallel and tilted {111} interfaces, originating from a 1-dimensional mismatch and including phenomena such as stand-off and dissociation of dislocations, was scrutinized.
Atomic-Force Microscopy of Gold Nanocrystallites on Smooth and Stepped Strontium Titanate Surfaces
Authors: Hamilton J. D. , Pap Anton Akis M. R. , Haglund R. F. , Godbole M. , Lowndes D. H. 
Published: April 2011

ABSTRACTWe have studied the nucleation and growth of Au nanocrystallites with dimensions of tens of nanometers on strontium titanate surfaces using an atomic force microscope. Strontium titanate ablated from a pressed pellet target by a KrF laser was deposited on both planar and offcut strontium titanate substrates. In a separate step, submonolayer quantities of gold were deposited, also by pulsed laser deposition, on the strontium titanate. The surfaces were then scanned by an atomic-force microscope to determine the effects of surface defects (such as steps and kinks on offcut surfaces), substrate temperature, and gold ablation yield on the nucleation, growth and size distribution of the nanocrystallites. The competition between diffusion and nucleation on planar vs stepped surfaces was particularly apparent in the AFM images. These results suggest several ways in which lateral decoration of the strontium titanate by the gold nanocrystallites can be achieved, an important step toward designer nonlinear photonic materials.
Effect of Atomic Bonding on Defect Production in Collision Cascades
Authors: Nordlund K. , Averback R. S. , Diaz de la Rubia T. 
Published: April 2011

ABSTRACTWe study the mechanisms of damage production during ion irradiation using molecular dynamics simulations of 400 eV -10 keV collision cascades in four different materials. The materials Al, Si, Cu and Ge are contrasted to each other with respect to the mass, melting temperature and crystal structure. The results show that the crystal structure clearly has the strongest effect on the nature of the damage produced, and elucidate how the open crystal structure affects the nature of defects produced in silicon.
The effect of the extra ion on residual damage in MeV implanted Si
Authors: Libertino S. , Benton J. L. , Coffa S. , Jacobson D. C. , Eaglesham D. J. , Poate J. M. , Lavalle M. , Fuochi P. G. 
Published: April 2011

AbstractWe have investigated the defect structure of ion-implanted and electron irradiated crystalline Si using deep level transient spectroscopy measurements to characterize both vacancy-(V) and interstitial- (I) type defects and to monitor their evolution upon annealing at temperatures ≤ 600 °C. It is found that only 4% of the Frenkel pairs generated by the energetic particles escape direct recombination and are stored into an equal number of room temperature stable V- and I-type defect complexes. No difference is found in the defect structure and annealing kinetics of ion implanted (1.2 MeV Si to fluences between 1×109 to 1010/cm2) and electron irradiated (9.2 MeV to fluences between 1 and 3×1015/cm2) samples in spite of the fact that denser collision cascades are produced by the ions. Annealing treatments result in a concomitant reduction in the concentration of I and V-type defects, demonstrating that defect recombination occurs preferentially in the bulk and not at the sample surface. Finally, at temperature above 300 °C, when most of the vacancy-type defects have been recombined, a residual concentration of I-type defects is found in ion implanted samples. This interstitial excess, not detected in electron irradiated samples, provides a direct evidence of the imbalance between I and V concentration produced by the extra incorporated ion.
Characterization of interstitial defect clusters in ion-implanted Si
Authors: Benton J. L. , Libertino S. , Coffa S. , Eaglesham D. J. 
Published: April 2011

ABSTRACTWe have investigated the properties of Si interstitial clusters in ion implanted crystalline Si. Deep Level Transient Spectroscopy measurements have been used to characterize the residual damage in Si samples implanted with Si ions at fluence in the range 1×109-1×1012/cm2 and annealed at temperatures of 100–700 °C. We have found that, in the fluence and annealing temperature range where extended defects are not formed, the residual damage is dominated by Si interstitial clusters which introduce deep levels at Ev+0.36 eV and at Ev+O-53 eV. By using Si substrates with a different impurity and dopant content, we have found that C, O and B play a role in determining the defect growth kinetics but are not the main constituents of these clusters. We estimate that 40 to 125 Si self intersti-tials are stored in these clusters and believe that they are the main source of Si self-inter-stitials in transient enhanced diffusion phenomena occurring in the absence of {311} or extended defects.
Interatomic Potential for Condensed Phases and Bulk Defects in Silicon
Authors: Justo J. F. , Bazant M. Z. , Kaxiras E. , Bulatov V. V. , Yip S. 
Published: April 2011

ABSTRACTWe present a new empirical potential for silicon which is a considerable improvement over existing models in describing structures away from equilibrium, such as bulk defects. The interatomic interaction is described by two- and three-body terms using theoretically motivated functional forms which emphasize chemical and physical trends. The numerical parameters in the functional forms are obtained by fitting to several ab initio calculations, which include bulk phases and defect structures. The model is tested to core properties of partial dislocations in the glide set {111}, which are not included in the database, and gives results in very good agreement with ab initio calculations. This is the only known potential capable of describing the structure of both the 30°- and 90°-partial dislocations.
Fick's Law and Transient Diffusion of Boron in Silicon
Authors: Wu David T. 
Published: April 2011

ABSTRACTThe phenomenon of transient diffusion of boron in crystalline silicon is considered. The local equilibrium assumption from the law of mass action is not used in order to estimate the length of the transient regime. For an interstitial diffuser such as boron, the pair of diffusion equations, one each for the mobile and the immobile species, can be interpreted as a generalized Fick's Law in the total concentration with a position- and time-dependent diffusion coefficient whose concentration-weighted average, called the global diffusion coefficient, has an analytic solution for an appropriately defined time-lag. At 850°C for boron, the transient in the global diffusion coefficient is negligible, showing that the local equilibrium assumption is justified. An estimate is given for conditions under which local equilibrium may not be valid.
Point and Extended Defect Interactions in Silicon
Authors: Law M. E. , Earles S. K. 
Published: April 2011

ABSTRACTTransient Enhanced Diffusion (TED) is one of the biggest modeling challenges present in predicting scaled technologies. Damage from implantation of dopant ions changes the diffusivities of the dopants and precipitates to form complex extended defects. Developing a quantitative model for the defect behavior during short time, low temperature anneals is a key to explaining TED. The surface can play a defining role in the removal of point defects from the bulk, but there is a lot of controversy over the role and strength of the surface sink for point defects. The controversy will be reviewed, and new experimental results will be presented that investigate the role of the surface on TED.
Simple Computer Modeling of the Grain Microstructure of Al-4wt%Cu Interconnection Lines
Authors: Low K.S. , Bull S.J. , O'Neill A.G. 
Published: April 2011

ABSTRACTA simple computer model is proposed to simulate the microstructural evolution of Al-4wt%Cu lines. The model includes the coarsening and pinning of Al2Cu precipitates which occur during normal grain growth. This model is used to explore how Cu-rich precipitates evolve during normal grain growth, and how they affect the evolution of grain structure from polycrystalline to bamboo.
An Examination of Mass Transport Paths in Conventional and Highly Textured AL-CU Interconnect Lines
Authors: Gleixner R. J. , Kanekof H. , Matsuot M. , Toyodat H. , Nix W. D. 
Published: April 2011

ABSTRACTThe electromigration lifetime of aluminum interconnect lines shows a strong dependence on the quality of the texture in the metal. This observation has been explained in terms of a decreased diffusivity along the grain boundaries, generally the dominant path for diffusion and void growth. As the texture in the metal is strengthened, atomic order along the grain boundaries is increased, and diffusion is suppressed.In this paper, we examine passivated A1–0.5wt%Cu interconnect lines having either TaAl underlayers or conventional Ti/TiN underlayers. Rocking curve measurements confirm that Al deposited on TaAl has a very strong (111) texture (FWHM ∼ 0.6°) compared to Al on Ti/TiN (FWHM ∼ 6°). Interconnect lines of both types were electrically stressed at 225°C and 250°C for 20 hours at a current density of 3 MA/cm2. The lines were then stripped of passivation, and the void numbers, sizes, and morphologies were determined.Analysis of the void data gave a surprising result: the void volume in the highly-textured Al was greater than in the conventional Al. However, voids in the conventional Al were observed to follow grain boundaries across the width and sever the line, while such destructive void growth was not observed in the highly-textured Al. Instead, voids grew either with a faceted shape or along the line edge, never extending across the line width. Modeling electromigration in the surrounding microstructures shows that void locations in the highly-textured lines are often independent of the surrounding grain boundaries. In this case, the line sidewalls appear to be significant mass transport paths. Since these paths do not cross the line width, voids growth across the line is difficult. This resistance to fatal damage makes highly textured aluminum a promising interconnect material.
Microstructural Identification of SiNx Films by Real-Time Ellipsometry
Authors: Soto G. , Samano E. C. , Machorro R. , Avalos M. , Cota L. 
Published: April 2011

ABSTRACTReal-time ellipsometry has shown to be a powerful tool to analyze thin films during processing. It is non-disturbing and its sensitivity lies in the submonolayer range. In fact, a slight variation in the film microstructure might result in a significant change of the polarization state of the reflected beam from the sample surface. SiNx layers have been grown on glass, quartz, KC1 and Si substrates by laser ablating a Si3N4 sintered target in vacuum and N2 environment. The film growth was monitored by real time ellipsometry at a fixed wavelength, and a fixed incidence angle. Once the deposition process is completed, the refractive index was obtained by perfoming in situ spectroellipsometric measurements in the 1.5 to 5 eV photon-energy range. The best curve fitting of the experimental data is used to find the film composition: a mixture of Si3N4, polycrystalline Si, and amorphous Si. The films composition and micro structure inferred from ellipsometric data are compared to those obtained by in-situ surface techniques and TEM, respectively.
The Recrystallization Properties of Poly-GexSi1-xON SiO2/Si
Authors: Jiang N. , Ma J.R. , Wu M. , Huang X.D. , Gu S.L. , Yu S.D. , Hu L.Q. , Zheng Y.D. 
Published: April 2011

ABSTRACTIn this paper, we have developed a new way to recrystallize the poly-GeSi on SiO2. 300nm poly-GeSi was grown by RTP/VLP-CVD on SiO2/Si, and then amorphized by 180 keV-Si+ ion implantation with dose of 2×10'4 cm'2. An amorphized region with the damage distribution was formed. After subsequent annealing process, the comparison between the XRD scans and Raman spectra of poly-GeSi and poly-Si indicated that the annealed poly-GeSi was more recrystallized than the poly-Si in the same conditions, this was the inducement of Ge in the annealing process. The segregation of Ge atoms in the heavy damaged region would enhance this inducement. The XTEM showed the longitudinal pattern of GeSi grains which meant the longitudinal sizes were much greater than the horizontal sizes. After annealing process, the final GeSi grain sizes were greater than the poly-Si grain sizes processed in SSIC with the same implantation conditions.
Ferroelectric Properties and Crystalline Structures of BaMgF4 Thin Films Grown on Pt(111)/SiO2/Si(100)
Authors: Moriwaki Masashi , Aizawa Koji , Tokumitsu Eisuke , Ishiwara Hiroshi 
Published: April 2011

ABSTRACTCrystalline quality and ferroelectric properties of (120)-oriented BaMgF^BMF) films grown on Pt(111)/SiO2/Si(100) and n-Si(111) substrates have been investigated. The BaMgF4 films grown on Pt(111) have large and flat grains, while the films on Si(111) have small grains. The C-V curve of BaMgF4/Pt(111)/SiO2/Si(100) diodes showed a hysteresis loop with a memory window of 3.8V.
Organic Contamination of Silicon Wafer in Clean Room Air and its
Impact to Gate Oxide Integrity
Authors: Imafuku D. , Mizubayashi W. , Miyazaki S. , Hirose M. , Wakayama Y. , Kobayashi S. 
Published: April 2011

ABSTRACTOrganic adsorbates on silicon wafer surfaces exposed to superclean room air
were measured to evaluate organic contamination level of silicon wafers
stored in a clean bench up to 180min. Such Si wafers were thermally oxidized
and the dielectric degradation behavior were systematically investigated. It
is found that a carbon contamination level of half a monolayer influences
the charge to quasi-breakdown although the degradation mechanism itself
remains unchanged.
Study on the effect of Silicon surface cleaning processes on
Gate Oxide Integrity
Authors: Corradi A. , Borzoni E. , Godio P. , Borionetti G. 
Published: April 2011

ABSTRACTThe effect of different silicon wafer surface preparation in modulating gate
oxide quality performance has been studied through an experimental design
which examines key phases of wafer cleaning and polishing processes. An
interpretation of the root causes of GOI degradation has been
proposed and discussed.
Understanding the Correlation of SurfaceSIMS and TXRF
Measurements of Surface Metal Contamination on Silicon
Wafers
Authors: Smith Stephen P. , Metz Jenny 
Published: April 2011

ABSTRACTA comparison of SurfaceSIMS measurements of surface metal contamination on
silicon wafers with TXRF analyses of the same wafers is presented. These two
important surface analysis techniques are characterized by differing
analytical areas and sampling depths. For Fe, agreement between SurfaceSIMS
and TXRF results is good (generally within a factor of two) for silicon
wafers from a variety of sources with contamination levels ranging from
8×109 to 2×1015 atoms/cm2. Differences
between SurfaceSIMS and TXRF results occur for other elements (such as W and
Cu) when the contamination is not uniform across the surface of the wafer
(particles are present), or extends a significant depth below the surface of
the wafer (as is frequently the case for ion-implanted wafers).
Acceleration of Organic Contaminant Adsorption Onto Silicon
Surfaces in the Presence of Residual Fluorine
Authors: Saga Koichiro , Hattori Takeshi 
Published: April 2011

ABSTRACTThe influence of fluorine atoms remaining after HF treatment on the
adsorption of organic contaminants onto the surface of silicon wafers was
investigated by analyzing the organic contaminants with gas
chromatography-mass spectrometry following thermodesorption (TDGC/MS), and
the surface composition with X-ray photoelectron spectroscopy (XPS). It has
been found that residual fluorine on silicon surfaces after cleaning of the
silicon wafers with either aqueous HF or anhydrous HF accelerates the
adsorption of organic contamination onto the silicon surfaces. This would be
due to the electrostatic force of attraction between the polar groups of
organic compounds and the residual fluorine on the silicon surface.
Detection of Low-Level Copper-Contamination on Silicon Surfaces
by Drop Nucleation
Authors: Lee Thomas D. , Spaepen Frans , Golovchenko Jene A. 
Published: April 2011

ABSTRACTNucleation and growth of liquid drops from the vapor can be used to locate
efficiently surface inhomogeneities such as topological defects, oxide
patches, metallic impurities, organic contamination, and particles. In this
study, nucleation of water drops was used to investigate the surfaces of
copper-contaminated silicon substrates. Hydrogen-terminated silicon (111)
substrates were dipped into copper-contaminated ultrapure water and exposed
to supersaturated water vapor. The amount of copper deposited was varied by
changing the strength of the solution. Nucleation occurred at vapor
pressures close to saturation. Higher densities of nucleated drops appeared
on areas with greater concentrations of copper. Using this technique, it was
possible to detect copper concentrations as low as 6×1011
atom/cm2. Below this concentration, treated and untreated
substrates could not be distinguished. The extreme sensitivity of the
technique to background nucleants shows its potential for efficient
screening of surfaces for a large range of inhomogeneities.
Improved Rinse Quench for a more Uniform Etch of Thermal Oxide
in Buffered Oxide Etch (BOE)
Authors: Parry T. B. 
Published: April 2011

ABSTRACTAn improved method for quenching a Buffered Oxide Etch (BOE) process in a DI
water overflow rinse tank is shown. Many different factors were investigated
in several preliminary experiments. Most of these factors were thought to
influence etch uniformity yet proved not to be significant. The transfer
process from chemical to rinse was identified as contributing negatively to
etch uniformity. A chemical carryover layer formed during the transfer
process was identified as the most significant factor. The hydrodynamics of
liquids are outlined to help explain how the carryover layer is formed and
shaped. Several sensitivity analysis experiments show transfer speeds to
significantly affect carryover layer thickness and uniformity. Slow transfer
speeds are determined to produce consistent and improved uniformity. Results
of a follow up experiment quantify the uniformity improvement.
Impact of Metal Contamination of 7.0nm Gate Oxides on Various
Substrate Materials
Authors: Saito S. , Hamada K. , Eaglesham D. J. , Shiramizu Y. , Benton J. L. , Kitajima H. , Jacobson S. D. C. , Poate J. M. 
Published: April 2011

ABSTRACTMetal contamination level will be decreased in order to maintain a device
reliability according to device size reduction. Metal contamination from
various processes are surveyed. The influence of metal contamination for
7–15nm thick gate oxides is discussed in order to clarify the critical
concentration to gate oxides. NIG(Non Intrinsic Gettering) substrates are
used in a worst case for gettering. Fe contamination with 4×1010
cm−2 strongly affects the TDDM characteristics, although there
is no serious influence in the breakdown voltage even at the concentration
of 5×1011 cm−2. The same tendency is observed for Cu
contaminant and the critical concentration for TDDB characteristics is
around 3×1011 cm−2. High energy B implantation is
carried out to form gettering sites near device region. Breakdown voltage
and TDDB characteristics are almost the same as epitaxial substrates at Fe
concentration up to l×1012 Cm−2. Detailed examination
such as SIMS, C-t and DLTS measurements is also supported the effectiveness
in high energy gettering.
Thermoelectric Transport in Superlattices
Authors: Reinecke T. L. , Broido D. A. 
Published: April 2011

AbstractThe thermoelectric transport properties of superlattices have been studied using an exact solution of the Boltzmann equation. The role of heat transport along the barrier layers, of carrier tunneling through the barriers, of valley degeneracy and of the well width and energy dependences of the carrier-phonon scattering rates on the thermoelectric figure of merit are given. Calculations are given for Bi2Te3 and for PbTe, and the results of recent experiments are discussed.
Optimization of Materials for Thermomagnetic Cooling
Authors: Migliori A. , Darling T. W. , Freibert F. , Trugman S. A. , Moshopoulou E. , Sarrao J. L. 
Published: April 2011

AbstractWe review thermoelectric transport in a magnetic field. The key physical effect for thermomagnetic cooling is the Ettingshausen effect. We describe the design principles, measurement difficulties and areas where more work can prove fruitful in an exploration of cryogenic refrigeration based on this effect. New principles are discussed to guide the search for new materials and their development.
unneling effects in InAs/GaInSb superlattice infrared photodiodes
Authors: Weimar U. , Fuchs F. , Ahlswede E. , Schmitz J. , Pletschen W. , Herres N. , Walther M. 
Published: April 2011

AbstractThe optical and electrical properties of InAs/GaInSb superlattice mesa photodiodes with a cutoff wavelength around 8 pim are investigated. The influence of the surface potential at the mesa sidewalls on the device properties was studied by fabricating gate-controlled diodes. At least two mechanisms determining the dark current in the reverse bias region can be identified. At high reverse biases bulk bandto- band tunneling dominates while the current at low reverse biases is most likely governed by surface effects. Bulk interband tunneling is further investigated by applying magnetic fields B up to 7 T parallel and perpendicular to the electric field E across the p-n junction.
Novel Piezoelectric Heterostructure for all-Optical Infrared Light Modulation
Authors: Ortiz V. , Pelekanos N. T. , Mula Guido 
Published: April 2011

AbstractWe present an innovative-design heterostructure based on the exploitation of in-the-barrier piezoelectric field for all-optical light modulation. The novel layout allows an efficient light modulation with low power densities (few tens of W/cm2), easily attainable with standard laser diodes. The modulation mechanism relies upon drastic photocarrier separation by the piezoelectric field in the barrier layers. We present room temperature results showing that an optical “control” power of 70 W/cm2 creates in the heart of the structure a space-charge field of about 30 kV/cm, inducing large spectral shifts (∼100 nm) in the photoluminescence spectra of a CdHgTe quantum well in the 1.5 μm range.