bluuebunny/crossref_metadata_2025_split huggingface dataset:
On holey polymer grids by condensation/dip-coating/draining/drying
Authors: Zheng Y , Li X , Vinson P K , Suszynski W , Davis H T , Scriven L E 
Published: July 2020

Abstract
Carbon-coated holey polymer film (HPF), or ‘holey carbon grid’ used to support fragile samples, is a crucial part of Cryo-TEM technique. A film with high porosity and uniform hole size as well as mechanical strength is needed. Efforts to develop a reliable preparation method date back to the 1950s. Today's favorite by far for routine application employs condensation, dip-coating, drainage and drying.it is not difficult, it affords control of hole size, and its yield is comparatively good. In this study, the mechanisms of hole generation and film formation were uncovered by means of in situ microscopy at medium working distance, super-VHS video recording and a high-speed motion analyzer, SEM and TEM.
Clean microscope slides were treated with Amine 105 (Kao-Atlas Co. Japan) to make the surface hydrophobic. A slide was then immersed in liquid nitrogen and exposed for 3 to 6 seconds to air with relative humidity of 30 to 60%.
Reduction of Charging in Biological Electron Cryomicroscopy
Authors: Sherman MB , Brink J , Chiu W 
Published: July 2020

Abstract
High resolution imaging in electron cryomicroscopy of biological macromolecules is strongly affected by beam-induced charging1. Charging is often expressed in frozen or glucose-embedded specimens as an increase in apparent mass-thickness of the irradiated area. Another obvious effect of charging is blurring of both the unscattered beam and reflections in electron diffraction patterns recorded from crystalline specimens. Coating of ice-embedded specimens with a carbon layer helps to improve the stability of the ice and probably reduce charging of the specimen. Coating in a Gatan ion-beam coater (model 681) of glucose-embedded specimens with thin layers of various conductive materials did reduce charging but the specimens were damaged by the high energy ions used for the coating. In general, coating resulted in much weaker reflections in electron diffraction patterns obtained from coated crystals and faster resolution fall-off.
We modified the Gatan coater by outfitting it with a new chamber that replaced the ion-beam deposition capability for thermal evaporation of carbon rods (Fig. 1).
Electron Microscopic Demonstration of the Photoconversion of a Fluorescent Label in Mixed Neuroglial Cultures
Authors: Ann Randall Kelly , Achim Cristian L , Wiley Clayton A , Dallasta Linda M 
Published: July 2020

Abstract
Endothelial cells (EC) possess receptors for and metabolize low-density lipoprotein (LDL); acetylation of LDL promotes EC metabolism and the intracellular deposition of its cholesteryl ester component. In turn, acetylated LDL linked to the fluorescent dye, Dil (Dil-Ac-LDL), has been used as a marker for endothelial cells, including cerebral microvascular endothelial cells (CEC). Due to the low electron density of fluorescent dyes, however, detection of this marker is not possible ultrastructurally. We demonstrate here the photo-conversion of the chromogen, 3,3'-diaminobenzidine tetrahydrochloride (DAB), into a stable, electron-dense reaction product in subcultured human fetal CEC containing the fluorescent marker, Dil-Ac-LDL, thus promoting identification of these cells via light and electron microscopy. This method, in turn, may be useful in identifying and tracking human fetal CEC grafted into SCID mice as a model for blood-brain barrier angiogenesis.
Isolated human fetal CEC were subcultured and labeled with Dil-Ac-LDL (10 ug/ml).
Light Microscopy Image Collection: Confocal, Widefield and Deconvolution
Authors: Turner J N , Szarowski D H , Roysam B , Holmes T J 
Published: July 2020

Abstract
Light microscopy instrumentation and biological applications continue to expand rapidly, and an important aspect of this expansion is three-dimensional (3-D) imaging and image analysis. For many biological specimens, optical sectioning, i.e. collecting images at a sequence of depths under controlled conditions, provides true 3-D data through the entire specimen. This is especially important for specimens whose thickness exceeds the depth-of-field of the microscope objective lens. This sequence of optical sections is the basis for 3-D image reconstruction providing information from all three specimen dimensions instead of just the traditional two in the image plane of the microscope. The analysis of images in 3-D provides insights into the structure and function of biological specimens that are not available through other means. However, 3-D microscopy also presents additional choices for image collection. The first of which is whether to use widefield or confocal microscopy and the second is whether to utilize digital deblurring or deconvolution methods.
Quantitative Three-Dimensional Image Analysis: Confocal and Widefield Light Microscopy
Authors: Roysam B , Holmes T J , Szarowski D H , Turner J N 
Published: July 2020

Abstract
Three-dimensional (3-D) light microscopy has been rapidly expanding for several years, both with respect to instrumentation, and biological applications. This new technology has transformed light microscopy from two-dimensional imaging of 3-D objects to a fully 3-D science. To date, qualitative analysis, reconstruction, and visualization has received far more attention compared to quantitative analysis. The motivations for 3-D image analysis are manifold, and include more accurate morphometry, separation of overlapping objects, and analysis of non-planar regions of interest and of thick specimens without the artifacts arising from physical sectioning. Furthermore, automating this analysis makes it fast, inexpensive, objective, and precise, and the results can be validated by manually confirming the analysis for any selected subset of 3-D images.
Increasingly, quantitative 3-D image analysis is emerging as an attractive technology for many applications. Studies include the testing of human-use products (shampoos, laxatives etc.), drug development, aging and development, cell loss/proliferation, fetal alcohol syndrome, and analysis of medical samples such as Pap smears, breast biopsies and a variety of cancers.
Atom-Bridge to Nano-Wire
Authors: Takayanagi K , Kondo Y , Ohnishi H , Ru Q , Kimata H 
Published: July 2020

Abstract
Nano-fabrications are now available for us to produce well-defined nano-structures showing quantum effects, quantized electron conductance at point contact, of phase interference of electron waves at quantum wires, and single electron tunneling at nano-capacitors. It seems near that we can fabricate even such nano-structures that Professor L.Feynman had described in his book “miniaturization”: the smallest memory unit(nano-particle), which contains 5x5x5 atoms. Such nano-particles are expected to have physical and chemical properties depending on their surface nature, since they have rather large volume of surface atoms compared with that of the core atoms. The surface atoms of such nano-particles might be reconstructed to a structure different from their bulk crystal structure, as well the surfaces of silicon and GaAs are reconstructed. It is, therefore, interesting to fablicate such nano-particles and to study their structures.
To study structure and properties of nano-particle surfaces, we developed a UHV high-resolution electron microscope equipped with a field-emission gun (UHV-FE-HR TEM: revised version of JEOL 2000V) at our ERATO project, as shown in fig. 1.
Mechanical Properties of Carbon Nanotubes Inferred from TEM
Authors: Treacy M M J , Ebbesen TW 
Published: July 2020

Abstract
The discovery of carbon nanotubes by Iijima has stimulated considerable research into their structural, chemical, electrical and mechanical properties. Apart from their intrinsic beauty as macromolecules, and their possibilities as one-dimensional conductors, researchers are stimulated by the notion that a structurally perfect nanotube may be one of the strongest known materials.
It is known that when nanotubes are bent through large angles, regions of high curvature buckle to develop crimps, similar to those observed when metal pipes are bent too much. Figure la shows a multi-walled nanotube that has one end embedded in a ceramic matrix. The other end is snagged so that the tube is bent. Several crimps are visible on the nanotube. Figure lb shows the same nanotube imaged a few moments later. Remarkably, the nanotube has sprung straight and the crimps have disappeared. This demonstrates that buckling in nanotubes does not involve plastic deformation, and that nanotubes can maintain their structural integrity even after severe deformation.
Three-Dimensional Hexagonal Close-Packed Superlattices of Passivated Ag Nanocrystals
Authors: Harfenist S A , Wang Z L , Whetten R L , Vezmar I , Alvarez M M , Salisbury B E 
Published: July 2020

Abstract
Silver nanocrystals passivated by dodecanethiol self-assembled monolayers were produced using an aerosol technique described in detail elsewhere [1]. Self-assembling passivated nanocrystal-superlattices (NCS's) involve self-organization into monolayers, thin films, and superlattices of size-selected nanoclusters encapsulated in a protective compact coating [2,3,4,5,6,7]. We report the preparation and structure characterization of three-dimensional (3-D) hexagonal close-packed Ag nanocrystal supercrystals from Ag nanocrystals of ˜4.5 nm in diameters. The crystallography of the superlattice and atomic core lattices were determined using transmission electron microscopy (TEM) and high-resolution TEM.
SEM was used to image the nanocrystal superlattices formed on an amorphous carbon film of an TEM specimen grid (fig. la). The superlattice films show well shaped, sharply faceted, triangular shaped sheets. Figure lb depicts numerous Ag nanocrystal aggregates uniformly distributed over the imaging region. Inset in this figure is an enlargement of the boxed region at the edge of a supercrystal typifying the ordered nanocrystal packing.
Electron Energy Loss Spectroscopy on Aggregated Fe-Cu-B Nanosized Particles
Authors: Duxin N , Brun N , Colliex C , Pileni M P 
Published: July 2020

Abstract
Nanostructured materials have attracted great attention because their physical and chemical properties may differ significantly from those of the bulk material. In the equilibrium state, the solid solubility between Fe and Cu is negligibly small. However by using methods as vapor quenching, ball milling or chemical reduction, a Fe-Cu solid solution can be formed. In the present work, colloidal solutions incorporating mixtures of iron (II) and copper (II) functionalized surfactants are used to obtain FexCu 1-x(B) alloys and composite. Different ranges of composition (x=0.3 and x=0.7) can be produced by varying the relative concentration of the surfactants.
The samples are characterized by different techniques, some of them such as X-ray diffraction, 57Fe Mössbauer spectroscopy, and magnetization measurements, provide an information averaged over the whole specimen. Transmission Electron Microscopy, together with electron diffraction and EDS analysis, constitutes a first step towards submicrometer analysis of the produced material available as aggregates of nanosized particles deposited on holey carbon films.
High Resolution Electron Microscopy of a Novel Zeolite
Authors: Crozier PA , Chan IY , Chen CY , Finger LW , Medrud RC , Harris TV 
Published: July 2020

Abstract
Low-dose high resolution electron microscopy (HREM) is a useful technique for elucidating the structure of zeolites. In recent years a number of zeolite structures have been solved using combinations of different characterization techniques including adsorption measurements, powder x-ray diffraction and low-dose high resolution electron microscopy (for example see ref. 2). We have used these techniques to study the structure of a novel zeolite material. However, great care must be exercised when interpreting data from these techniques in terms of crystal structural units. In this particular case, the structure was recently determined using single crystal x-ray diffraction and showed some surprises.
Details of the synthesis of this zeolite are given elsewhere. The high adsorption capacity suggested that this zeolite possessed two interpenetrating channels (either a 10 and a 12 ring or two 12 ring channels). X-ray powder diffraction showed the material to be monoclinic with a= 18.5Å, b= 13.4 Å, c= 7.6 Å β = 101.5°).
Microscopy as a Problem Solving Tool in Semiconductor Development and Manufacturing
Authors: Joseph TW 
Published: July 2020

Abstract
Problems in semiconductors and integrated circuits range from crystalline defects to contamination to misformed structures. They may be due to a single event (e.g. foreign particle) or a complex interaction between materials, processes, and environment. Many clues for the cause of these problems can be obtained from in-line measurements, such as electrical device behavior or layer thickness, but it is often not until after a defect or abnormal structure is seen that it is fully understood. The method of “seeing” must allow the normal to be distinguished from the abnormal and ultimately the reason for the difference to be determined. Vast amounts of data are often generated to electrically understand a defect or determine the reliability implications of a problem but it is often not until microscopic analysis is performed that the problem is fully revealed. It is not uncommon for just a small number of images bring to light the origin of a problem and lead to a solution.
Atomic Structure of Si-SiO2 Interface
Authors: Duscher G , Banhart F , Müllejans H , Pennycook SJ , Rühle M 
Published: July 2020

Abstract
Investigations of the atomic structure of Si-SiO2 interfaces have mostly been performed with high resolution transmission electron microscopy. However, the interpretation of the phase contrast in the amorphous phase at the interface is not unique. While Ourmazd et al. concluded on a crystalline phase at the Si-SiO2 interface, Akatsu and Ohdomari attributed the same contrast to an interface roughness parallel to the incident electrons.
We investigated the Si-SiO2 interface by studying the ELNES of the O-K edge with the spatial difference technique with a dedicated STEM with l00kV (VG HB501 UX). Also the interface was studied by Z-contrast imaging with a 300 kV dedicated STEM (VG HB603 U). Silicon wafers (110) were first thermally oxidised to produce a SiO2 layer. The thermally grown oxide was used as a substrate for liquid phase epitaxy of silicon, given two {111} Si-SiO2 interfaces in the sample grown by two different techniques (see fig. 1).
Applications of TEM for Analysis of Local Failures Occurring During Silicon Metallization Process
Authors: Lee Hoojeong , Sinclair Robert 
Published: July 2020

Abstract
As the size of integrated circuit devices continues to decrease, the ratio of interfacial area to volume increases and the dimension of thin films shrinks to the order of tens of nanometers. In such circumstances, the interfacial reactions, which are frequently accompanied with nanometer scale local failures, become a dominant mechanism for the breakdowns of the devices at high temperatures. This makes transmission electron microscopy (TEM) take a unique role in the research of Si metallization. In situ techniques have succeeded to reproduce and observe such real time reactions in the TEM. Moreover, after the introduction of the field emission gun systems(FEG), there have been enormous improvements in the spatial resolution and performance of x-ray energy dispersive spectroscopy (EDS) and electron microdiffraction. In the present work, two case studies of local failure were successfully investigated by combining these techniques: TiN diffusion barrier breakdown between Si and Al, and TiN electrodes on tantalum pentoxide (Ta2O5) capacitors for 1 Gigabit DRAM.
TEM Characterization of Arsenic and Phosphorus Implanted Silicon Devices
Authors: Tsung Lancy , Tsai Hun-Lian , Tsao Alwin , Takemura Makoto 
Published: July 2020

Abstract
Ion implantation of arsenic and phosphorus is a common practice in silicon devices for the formation of transistor source/drain regions. We used a TEM equipped with EDX capabilities to investigate effects of ion implantation in actual devices before and after annealing. A 200 kev field emission gun TEM was used in this study. Two implant cases were studied here. Both samples are p-type, (100) Si wafers.
Figure 1 shows the microstructure in a common source region of a silicon device after being implanted by phosphorus (4x1014 cm−2 at 30 kv, 0°), while Figure 2 shows a similar region for arsenic implantation (5x1015 cm−2 at 45 kv, 0°). No screen layer was used during implantation. The phosphorus implant results in a ˜0.05 μm amorphous layer sandwiched between heavily damaged crystalline silicon. High resolution images reveal a rough amorphous/damaged crystalline boundary and high density defects due to silicon lattice displacements.
Applications of High Spatial Resolution Analytical Electron Microscopy to the Process Development of Silicon Devices
Authors: Ameirhekmat B , Tsung LY , Tsai HL , Lu JP 
Published: July 2020

Abstract
Analytical transmission electron microscopy (AEM) equipped with a field emission gun has made it possible to analyze chemical information at local spots or interfaces with a very small electron probe. This technique has been applied to assist in process development and addressing certain reliability issues in silicon devices.
Figure 1 shows an example of applications of AEM to a 0.5 μm transistor. An oxide bump is found to be located in the middle of a transistor. A very thin layer (20 Å) is on the top of the oxide bump. Using EDS, the bump is determined to be a silicon oxide, but EDS failed to analyze the thin layer. Electron energy loss spectroscopy detects nitrogen in this residual layer (Fig. la), suggesting that the residue is a thin nitride. This residual nitride is caused by the incomplete removal of the nitride mask after field oxidation. This nitride residue blocks the subsequent removal of the buffer oxide between the nitride mask and the substrate.
In-Situ Transmission Elecron Microscopy (TEM) Study of the Nitridation of Basal Plane Sapphire by Reactive Molecular Beam Epitaxy (RMBE)
Authors: Yeadon M , Marshall MT , Gibson JM 
Published: July 2020

Abstract
Group III-nitride thin films are currently of great interest for use in wide-bandgap semiconductor applications including UV lasers and light emitting diodes (LEDs). Sapphire (a-Al2O3) is currently the substrate of choice for the growth of GaN despite a large lattice mismatch. Growth of high quality GaN epilayers typically involves the deposition of a buffer layer of either AIN or GaN at a temperature well below that used for the growth of the active GaN layer. It has been found empirically that nitridation of the sapphire surface with nascent nitrogen prior to growth of the buffer layer results in a substantial improvement in film quality. Using a novel ultra-high vacuum (UHV) in-situ TEM with in-situ RMBE, we have studied the nitridation of the (0001) sapphire surface using transmission and reflection electron microscopy (REM), reflection high energy electron diffraction (RHEED) and Auger electron spectroscopy (AES).
An electron-transparent sapphire TEM sample was annealed at 1400°C for 12 hours in flowing oxygen, to form atomically flat surfaces for our investigation.
The Influence of Dopant Type on Polysilicon Grain Growth and Solid Phase Epitaxial Regrowth
Authors: Shlepr MG , Schrantz GA , Rivoli AL , Bajor G 
Published: July 2020

Abstract
A recent process technology to manufacture bipolar junction transistors utilizes polysilicon emitters. Polysilicon is deposited, appropriately doped to form both NPN and PNP transistors, and exposed to temperatures that result in grain growth. Since polysilicon is in contact with Si( 100) at the emitter, base, and collector (Fig. 1), solid phase epitaxial regrowth might also occur. Production runs with this structure occasionally produce transistors with low current gain. High and low gain NPN and PNP transistors were characterized by transmission electron microscopy.
Vertical sections through NPN/PNP transistor arrays were made by the wedge technique, low-angle ion milled to electron-transparency, and viewed at 200 KV. The grain size of the polysilicon on oxide was recorded and estimated. The extent of epitaxial regrowth was quantified for each of the Si (100) contact areas. Convergent Beam Electron Diffraction (CBED) was used to confirm the orientation of the presumed regrown polysilicon.
3-D Observation of Cu Particles Precipitated in Si by High-Angle Hollow-Cone Dark-Field Transmission Electron Microscopy
Authors: Kakibayashi Hiroshi , Nakamura Kuniyasu , Tsuneta Ruriko 
Published: July 2020

Abstract
The performance of electronic devices, such as dynamic random access memories, is degraded by contamination due to impurity atoms as well as crystalline imperfections created during processing. The evaluation of those degradation causes is generally done using an analytical transmission electron microscope. The information obtained, however, is limited to two-dimensional images of the specimen as seen from a single direction. Advanced semiconductor devices with finer-pattern structures are expected to exhibit larger fluctuations in device performance due to the spatial distribution of the faults. A new method has thus been examined to determine the atomic species and to reconstruct three-dimensional (3-D) images of the specimen structure by using high-angle hollow-cone dark-field transmission electron microscopy (HADF-TEM).
A incident angle controller was added to a conventional TEM to control the electron-beam deflection coils. This enables the incident electron beam to be inclined and rotated, providing hollow-cone illumination of the specimen, as shown in Fig. 1.
A Novel Method for Contactless, Non Destructive Investigation of Semi Conductor Structures in the SEM.
Authors: Rau EI , Robinson VNE 
Published: July 2020

Abstract
It is known that scanning a focussed laser beam across the surface of a semi conductor wafer, can produce a photon induced voltage (PIV) at electrically active sites. This technique depends upon the incident photons inducing charge carriers, both electrons and holes, on or just below the surface of the semi conductor. These charge carriers drift through the device until they are captured by a defect, at which stage they accumulate, producing a voltage at the surface. These voltages are only associated with a charge carrier capture site, which means that a voltage build up only occurs at a defect. This PIV technique has been used for contactless imaging of semiconductor wafers, allowing easy identification of electrically active sites such as crystallographic defects, imperfections and inhomogenieties on or just below the surface [1,2].
Nothing in the above mechanism excludes the use of an electron beam to induce charge carriers and produce an electron induced voltage (EIV).