bluuebunny/crossref_metadata_2025_split huggingface dataset:
FCC Superlattice Packing of Faceted Silver Nanocrystals
Authors: Harfenist SA , Wang ZL , Alvarez MM , Vezmar I , Whetten RL 
Published: July 2020

Abstract
The ordering of size selected nanocrystaline particles into large, well ordered supercrystals has been under recent study. Here we describe the ordering of silver nanocrystals, of core diameter ca. 4.5nm, passivated with alkythiolate self-assembled monolayers. The faceted nanocrystals are found to size selectively condense into ordered supercrystals with edge lengths on the order of 0.1 to 0.5 microns. Further, evidence has been found in High Resolution TEM micrographs of packed monolayers of these same nanocrystals implying an orientational ordering of the silver nanocrystals’ atomic lattices within and co-aligning with the supercrystal’s “superlattice”. A three dimensional model using a truncated octahedron for the nanocrystal core morphology is constructed from this evidence into an FCC superlattice which fits the remaining experimental observations.
Micrographs of the same region of a nanocrystal Ag supercrystal (NCASX) are shown in figure 1 under differing defocus conditions.
HRTEM Study of Sputtered Cu-6at% Ta Films
Authors: Liu Y , Wang H , Mazumder J , Rigsbee JM 
Published: July 2020

Abstract
Cu-refractory metal composites such as Cu-Ta alloys are attracting research interest because of their potential high electrical and thermal conductivity and high mechanical strength at elevated temperatures [1]. In the previous study, it has been shown that the hardness of Cu-Ta is three times of the Cu substrate [2] and the Ta was found to exist as discrete particle and aligned particles. In this presentation, we report the detailed study on the microstructure of the heat treated film and hot-pressed film.
The Cu-6at%Ta films were deposited on Cu foil at 100°C by RF co-sputtering. The films examined in this study was hot-pressed under 35 MPa pressure at Ar atmosphere for 1 hour. Cross-sectional TEM samples were examined using a Hitachi 9000 high resolution transmission electron microscope (HRTEM) at the Center for Microanalysis, Materials Research Laboratory, University of Illinois at Urbana-Champaign.
TEM Studies of Silicon Nitride-Silicon Carbide Nanocomposites
Authors: Wang E Y , Pan X , Mansfield J P , Kennedy T , Hampshire S 
Published: July 2020

Abstract
Si3N4/SiC nanocomposites have been shown to exhibit excellent strength and fracture toughness compared to monolithic Si3N4 materials. Recently, the microstructure and chemistry of Si3N4-based nanocomposites fabricated by hot-pressing amorphous Si-C-N precursor powders has been investigated. In the present work, our studies on the microstructure of Si3N4/SiC nanocomposites made by hot-pressing the mixture of Si3N4 and SiC commercial powders are reported.
Si3N4/SiC nanocomposites were prepared by hot-pressing at 1750 °C for 1 hour at 40 Mpa in a nitrogen atmosphere, with sintering aids of 5.5 wt% Y2O3 and 3 wt% Al2O3. The details of the processing procedure have been reported elsewhere. Two different materials were investigated in this work: specimen A consisting of 5 vol% β-SiC; and specimen B consisting of 5 vol% α-SiC. TEM specimens were prepared by conventional procedures. The microstructure and chemical composition were studied in the University of Michigan Electron Microbeam Analysis Laboratory on a JEOL 2000FX.
The Examination of Calcium ion Implanted Alumina with Energy Filtered Transmission Electron Microscopy
Authors: Hunt EM , Hampikian JM , Evans ND 
Published: July 2020

Abstract
Ion implantation can be used to alter the optical response of insulators through the formation of embedded nano-sized particles. Single crystal alumina has been implanted at ambient temperature with 50 keV Ca+ to a fluence of 5 x 1016 ions/cm2. Ion channeling, Knoop microhardness measurements, and transmission electron microscopy (TEM) indicate that the alumina surface layer was amorphized by the implant. TEM also revealed nano-sized crystals ≈7 - 8 nm in diameter as seen in Figure 1. These nanocrystals are randomly oriented, and exhibit a face-centered cubic structure (FCC) with a lattice parameter of 0.409 nm ± 0.002 nm. The similarity between this crystallography and that of pure aluminum (which is FCC with a lattice parameter of 0.404 nm) suggests that they are metallic aluminum nanocrystals with a slightly dilated lattice parameter, possibly due to the incorporation of a small amount of calcium.Energy-filtered transmission electron microscopy (EFTEM) provides an avenue by which to confirm the metallic nature of the aluminum involved in the nanocrystals.
Dynamic Observation of the Thinnest Gold Nano-Bridge by Newly Developed UHVTEM
Authors: kondo Yukihito , Takayanagi Kunio 
Published: July 2020

Abstract
The nano-structure science have become popular as the nano-fabrication technology has progress recently. Among the nano-structures, the nano-wires have been attracted attention because they show quantized conductance which would be used in quantum devices[l]. The quantized conductance has been observed even at room temperature with the nano-wires prepared by tip-indentation in scanning tunneling microscope [2-4]. However, the direct observation of the nano-wires has not been examined because of lack of their stability and difficulty of specimen preparation.
We have generated a gold thin wire with the thickness ranged 0.8-2 nm, referred to as a nano bridge (NB)[5], in an ultrahigh vacuum transmission electron microscope (UHVTEM) [6]. The NB is stable at room temperature and shows good reproducibility. The shape of NB is surprisingly uniform (see Fig. 2). The structure is stabilized by stable hexagonally-closed-pack (hcp) planes for the NB of 2 nm in thickness [5]. The well-defined structure provide a good opportunities for applied and theoretical studies.
Procedure to Determine the Structure of Three-Horned Multishell Fullerene
Authors: Kondo Yukihito , Takayanagi Kunio 
Published: July 2020

Abstract
Fullerenes have many families such as simple ball-shaped fullerenes, nanotubes, and onions. Additionally torus, Y-shaped particle, and graphitic network with periodic holes or dimples have been theoretically anticipated. The presence of various shapes in fullerenes is mainly attributed to the combination of five-membered and seven-membered rings in addition to six-membered rings composing ordinary graphite crystal. The five-membered rings are necessary for positive curvature of the fullerenes, while the seven-membered rings for negative curvature. Experimentally, the negative curvature has been restricted so far to the joint between cone and tube in nanotubes and the spiral tubes. We have found a new type of multishell fullerenes with negative curvature which consist of three horns protrude into three-fold symmetric directions, referred as three-horned multishell fullerene (THF) in this report, using a high resolution transmission electron microscope (TEM). Here, we first describe the formation briefly and secondly concerned with procedure to determine the structure of the THF.
Nanoscale Patterning of BaTiO3 on Block Copolymers
Authors: Lee T , Yao N , Aksay I A 
Published: July 2020

Abstract
Nanoscale pattering of inorganics can be facilitated by using complex fluids as templates. One such approach is to use block copolymeric nanodomains in solid films (&lt; 50 nm) as the template for patterning ceramic clusters with desired shapes and orientations. For instance, we use a triblock copolymer of polystyrene (PS) -polybutadiene (PB) - polystyrene (PS) - Kraton Dl 102® (MW = 71,000 and PS/PB = 28%/78%) as a template material to pattern barium titanate for energy storage applications. The important features of our approach are that (i) the interdomains of PBs in the preformed solid thin films are chemically OH-functionalized in situ, and (ii) the barium titanate precursors are solely localized within and reacted to the interdomains of PBs in solid thin films by condensation.
Thin films were prepared by spin casting a 1% w/w Kraton D1102®/toluene solution on a coverglass. Thin films were transferred to gold TEM specimen grids by the water lift off method.
Characterization of Nanophase Particle Aggregates by Transmission Electron Microscopy
Authors: Gonzalez G , Freites A , Rojas C 
Published: July 2020

Abstract
In the last few years there has been a growing interest in nanoparticles and nanophase materials. Nanoparticles are considered to be a new state of the condensed matter due to the high relation of atoms in the surface respect to the number of atoms in the volume, and their properties are neither those of atoms nor those of bulk materials.
There are many interesting questions still to be answered and processes to be understood, from nucleation and growth processes to properties
In the present work we report the results of the fabrication of Mo, MoW and MoNi, particles by d.c. sputtering, under different pressures, from 0.2 torr to 0.8 torr. Their morphology, size distribution, aggregation and structure has been studied by Transmission Electron Microscopy.
We analyzed our results contrasting them with those of Chow 1,2 and Birringer 3 and try to explain with a new perspective the formation mechanism of the particles, and the dependence of particle size with Ar pressure.
Nano-Sized Catalytic Materials Investigated by a STEM-Based Mass Spectroscopic Technique
Authors: Yang J C , Singhal A , Bradley S , Gibson J M 
Published: July 2020

Abstract
Knowledge of catalysts' sizes and shapes on their support material is crucial in understanding catalytic properties. With increasing interest in nanosized catalytic materials, it is vital to obtain structural information at the nanometer level in order to understand their catalytic behavior. We have recently demonstrated that very high angle (˜100mrad) annular dark-field (HAADF) images in a dedicated scanning transmission electron microscope (STEM) can be used to quantitatively measure the number of atoms of individual nano-sized clusters on a support material We are presently applying this technique to a bimetallic catalyst, PtRu5, where our data suggest that the shape of the PtRu5 particle is, surprisingly, oblate on the carbon substrate.
PtRu5 is of interest for methanol oxidation for applications in batteries. PtRu5 compounds were produced by a molecular precursor method. Imaging was performed on a Field Emission Gun (FEG) Vacuum Generators HB501 STEM operated at 100kV.
Defect Review at 0.25 Micron Electron Optic Requirements and Practical Examples
Authors: Tracy Bryan 
Published: July 2020

Abstract
The sub-micron era in 1C process technology has been characterized by ever shrinking device geometries. When the minimum feature size of 0.5 micron was reached, a significant inflection in the usefulness of optical microscopy occurred. Seemingly routine Fab activities such as the use of the optical microscopes to determine the quality of the metal etch were no longer possible. At the same time, an increased use of defect inspection tools such as KLA and Tencor was required to insure stable process quality. These and other factors combined to hasten the introduction of multiple defect review scanning electron microscopes into the modern 1C Fab. This trend has accelerated during the process development of 0.25 micron technology. Accordingly, as leading 1C manufactures introduce production 0.25 devices, it is not unusual to find as many as six such instruments installed in a modern development or fabrication facility. As such, these instruments, commonly called Defect Review Tools (DRT's) constitute an increasing share of the Fab equipment set.
Imaging and Analytical Challenges for Nanoscale Semiconductor Technology: Breakthrough Needs for Development and Manufacturing
Authors: McDonald Robert C , John Mardinly A , Susnitzky David W 
Published: July 2020

Abstract
The complexity of today’s commercial semiconductors has contributed to tremendous gains in device performance; millions of transistors are now packed into each square centimeter of silicon. The reduction of scale occurring within the semiconductor industry places extraordinary new demands on transmission electron microscopy: TEM is becoming a required precision measurement tool for manufacturing and a necessary analytical tool for R&D and failure analysis support. This paper reviews the industry’s needs for advanced TEM sample preparation, imaging and microanalysis and outlines the challenges presented to the TEM community as device dimensions continue along the National Technology Roadmap.
In the semiconductor industry, TEM is applied to process debugging, yield engineering, tool qualifications, single-bit failure analyses, and new process development. A large fraction of the analysis effort focuses on transistor, metal, interconnect and dielectric structures grown on and into the Si wafer. Fig. 1 shows a TEM image of a multilayer metal in a near-current generation microprocessor to illustrate the scale and nature of complexity.
Characterization of Multilayered Structures Using a FEGSEM and X-Ray Microanalysis
Authors: Gauvin Raynald , Caron Mario , Fortin Vincent , Currie John F 
Published: July 2020

Abstract
Microelectronic processes now involve multilayer structures of different materials. It is important to control accurately the thickness and composition of these materials during their processing. The determination of these two physical parameters are usually performed by Elastic Recoil Detection (ERD), by Auger Electron Spectroscopy (AES) and Transmission Electron Microscopy (TEM). However, these techniques are not suitable for analysis on a routine basis. In this context, a quantitative procedure based on EDS X-ray microanalysis in the Scanning Electron Microscope has been developped because of its availability and its speed of analysis. However, this technique requires several measurement of K ratio taken at different voltages which is time consuming. With the advent of Field Emission Gun Scanning Electron Microscopes (FEGSEM), X-ray line scans taken at low electron beam voltage with an EDS system may be an alternative. In this paper, preliminary results using this technique on multilayered materials are presented.
To investigate this characterization technique, a AlSiCu(200 nm)/TiN(95 nm)/Ti(40 nm) multilayer metallization structure deposited on Si substrate was used. EDS X-ray line scans were obtained with a Hitachi S-4500 FEGSEM coupled with a Link ISIS 300 EDS system.
Comparison of Sputtered Titanium Nitride on Silicon Dioxide and Aluminum-Alloy Thin Films
Authors: Drown JL , Merchant SM , Gross ME , Eaglesham D , Giannuzzi LA , Irwin RB 
Published: July 2020

Abstract
Titanium nitride (TiN) films are used as anti-reflection coatings (ARC) on aluminum (Al) films to facilitate lithography processes during multilevel metallization for the manufacture of integrated circuits on silicon-based (Si) semiconductor devices. It is generally accepted in the literature that the microstructure of multilevel metal stacks is influenced by the texture of the substrate. For the case of interconnect materials used in the semiconductor industry, a typical metal stack is as follows: Titanium/Titanium Nitride/Al-alloy/ARC-Titanium Nitride. The Ti/TiN layer underneath the Al-alloy film is used as a barrier stack to prevent junction spiking. The Ti/TiN underlayer also determines the growth conditions (crystallography and orientation relationships) of the subsequent Al-alloy film.
This study focuses on the microstructural characterization of the ARC-TiN layer on Si-oxide and Ti/TiN/Al-alloy substrates that are fabricated under similar conditions using conventional physical vapor deposition (PVD - sputtering) techniques. The ARC-TiN microstructure was investigated by transmission electron microscopy (TEM) using a Philips EM430 operating at 300 kV.
Characterization of Variations in Schottky Barrier Height in Semiconductor Devices using EBIC Technique
Authors: Drouin D , Beauvais J , Gauvin R 
Published: July 2020

Abstract
Recent developments in microelectronic devices have increased the need for new investigative techniques. Much of the development on Electron Beam Induced Current (EBIC) occurred in the early 70's. Since that time, much of the work has been devoted to using this technique to investigate defects in semiconductor devices. Less attention has been focused on electrical measurement of semiconductor properties.
A digital EBIC method to characterize semiconductors has been developed and is presented here. The sample current is measured using a Keithley 670 electrometer controlled through a GPIB interface by a standard computer. The electron beam from the scanning electron microscope (SEM) is synchronized with the current acquisition. All the acquisition is controlled by a Labview virtual instrument (Figure 1).
As an example of the performance of this method, a special sample was analyzed. A novel method of resistless lithography process was developed in our laboratory. This technique is dedicated to overcome limits of conventional resist based electron beam lithography.
SIMS of Interfacial Segregation in Ceramics and Composites
Authors: Chabala JM , Gavrilov KL , Mikeska KR , Bennison SJ , Levi-Setti R 
Published: July 2020

Abstract
Trace impurities and dopants in sintered ceramics, often at levels below 100 parts per million, can significantly affect the performance of the materials. In alumina (A12O3), it is believed that calcium and silicon, which are the main background impurities, cause abnormal grain growth. The addition of magnesium to alumina produces several beneficial results, including enhanced densification and improved corrosion resistance of the ceramic. For example, LUCALUX®, which is a dense, transparent ceramic, is made by adding a small amount of MgO (&lt;0.25%) to the alumina. Primarily because they are difficult to detect and image, it has not been easy to determine experimentally the mechanisms by which trace constituents influence the sintering of ceramics. Imaging secondary ion mass spectrometry (SIMS) is a valuable analytical technique for the submicrometer characterization of ceramics. Relevant to this study, magnesium and isotopes of silicon, which have largely eluded detection by traditional techniques, can be measured with SIMS.
Interfacial Segregation Studied With Modern AEM Techniques
Authors: Bentley J 
Published: July 2020

Abstract
For more than 20 years interfacial segregation has been studied by analytical electron microscopy (AEM). Two recent commercial developments should allow more widespread application of 1 nm resolution AEM studies of interfacial segregation. The first is a system for integrated acquisition that in its most sophisticated form allows spectrum imaging [a full spectrum recorded at every pixel of an image (e.g. STEM)] for simultaneous multiple spectroscopies (e.g., EDS and PEELS). A field emission gun (FEG) is necessary for sufficient sensitivity at high spatial resolution. The second commercial development has been imaging energy filters that allow the production of elemental maps from a series of energy-filtered TEM (EFTEM) images at inner shell ionization edges. Resolutions of ∼1 nm can be achieved without an FEG, but analysis is limited to the electron energy-loss signal. Although complex microstructures may require full two-dimensional mapping, for many planar interfaces a one-dimensional profile of composition or chemistry normal to the interface plane is sufficient.
Quantitative Determination of Bi Segregation at Grain Boundaries in Cu Bicrystals
Authors: Alber U , Müllejans H , Rühle M 
Published: July 2020

Abstract
Impurity segregation at grain boundaries (GB) can be detected by EDS in a dedicated STEM. Quantification of the segregation requires not only quantification of the spectra but also consideration of the geometry of the experiment. Our aim was to obtain a value which characterises only the segregation of the impurity and is independent of experimental parameters. The problem is that the specimen composition at the GB is extremely inhomogeneous on an atomic scale in the case of Bi segregation at GBs in Cu. The analysed volume which is defined by the irradiated area and the beam broadening of the primary electron beam inside the specimen contains the interfacial plane as well as neighbouring bulk Cu. One approach is to put the focussed primary electron beam on the interface which is aligned edge on and acquire a spectrum. Both the primary beam diameter and the beam broadening inside the specimen have to be known.
Irradiation-Induced Microstructural Changes in Alloy X-750
Authors: Kenik EA 
Published: July 2020

Abstract
Alloy X-750 is a γ´-strengthened Ni-base alloy that is often used in nuclear power systems for its excellent corrosion resistance and good mechanical properties. However, radiation-induced segregation (RIS) and irradiation-assisted stress corrosion cracking (IASCC) can occur under neutron irradiation. The present study examines the microstructure and composition profiles in a heat of Alloy X-750 before and after neutron irradiation.
The material was in the HTH commercial heat treatment (lh at 1121°C + air cooling + 20h at 704°C). Specimens were prepared from both control material and material irradiated at 360°C to a fluence of 2.3 × 1020 n/cm2 (E &gt; 1 MeV), which was estimated to produce -0.4 displacements per atom. High spatial resolution analytical electron microscopy was performed in a Philips EM400T/FEG operated in the STEM mode with a probe diameter of ∼1.4 nm (FWHM). Composition profiles were acquired in two different ways: all energy dispersive X-ray spectrometry (EDS) and some parallel-detection electron energy-loss spectrometry (PEELS) profiles were acquired as individual spot analyses, whereas the majority of the PEELS profiles were acquired as spectrum lines with ∼10 s acquisition times per point. The quoted compositions are as measured (wt%); no deconvolution for the effect of the excited volume was performed.
Texture and Grain Boundaries in Epitaxial Oxide Multilayers, Including Superconductors, on Biaxially Textured Metal Substrates
Authors: Goyal A , Specht E D , Norton D P , Paranthaman M , List F A , Park C , Christen D K , Kroeger D M 
Published: July 2020

Abstract
A new technique, referred to as rolling-assisted-biaxially-textured-substrates (RABiTS) has recently been proposed by Goyal et al., to fabricate long-range, biaxially textured substrates with suitable metal/ceramic surfaces for epitaxial growth of electronic devices [1]. Using standard thermomechanical processing, long lengths of flexible, biaxially oriented substrates with smooth surfaces (rms∼50nm) are obtained [1]. Epitaxial metal and/or oxide layers which can serve both as a chemical as well as a structural buffer are deposited on the biaxially textured metal. The metal with a suitable set of epitaxial, multi-layers comprises the substrate which is expected to have many potential applications, including superconductivity, photovoltaics and ferroelectrics [1].
When high temperature superconductors are deposited on a set of epitaxial multilayers on biaxially textured RABiT substrates, extremely high critical current densities, approaching 106 A/cm2 at 77K have been obtained [2].