scholarly journals Quantification of STEM Images in High Resolution SEM for Segmented and Pixelated Detectors

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 71
Author(s):  
Ivo Konvalina ◽  
Aleš Paták ◽  
Martin Zouhar ◽  
Ilona Müllerová ◽  
Tomáš Fořt ◽  
...  
Keyword(s):  
Simulated Data ◽  
Array Detector ◽  
Objective Lens ◽  
Semiconductor Detectors ◽  
The Past ◽  
Radial Profiles ◽  
Pixel Array ◽  
Electron Microscopes ◽  
The Cost ◽  
Scanning Electron Microscopes

The segmented semiconductor detectors for transmitted electrons in ultrahigh resolution scanning electron microscopes allow observing samples in various imaging modes. Typically, two standard modes of objective lens, with and without a magnetic field, differ by their resolution. If the beam deceleration mode is selected, then an electrostatic field around the sample is added. The trajectories of transmitted electrons are influenced by the fields below the sample. The goal of this paper is a quantification of measured images and theoretical study of the capability of the detector to collect signal electrons by its individual segments. Comparison of measured and ray-traced simulated data were difficult in the past. This motivated us to present a new method that enables better comparison of the two datasets at the cost of additional measurements, so-called calibration curves. Furthermore, we also analyze the measurements acquired using 2D pixel array detector (PAD) that provide a more detailed angular profile. We demonstrate that the radial profiles of STEM and/or 2D-PAD data are sensitive to material composition. Moreover, scattering processes are affected by thickness of the sample as well. Hence, comparing the two experimental and simulation data can help to estimate composition or the thickness of the sample.

Observation of GaAs/AlAs Superlattice Structures in both Secondary and Backscattcred Electron Imaging Modes with an Ultrahigh Resolution Scanning Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 404-405
Author(s):  
K. Ogura ◽  
A. Ono ◽  
S. Franchi ◽  
P.G. Merli ◽  
A. Migliori
Keyword(s):  
Gaas Layer ◽  
Objective Lens ◽  
Superlattice Structure ◽  
Backscattered Electron ◽  
Instrumental Resolution ◽  
Electron Microscopes ◽  
Superlattice Structures ◽  
Electron Imaging ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

In the last few years the development of Scanning Electron Microscopes (SEM), equipped with a Field Emission Gun (FEG) and using in-lens specimen position, has allowed a significant improvement of the instrumental resolution . This is a result of the fine and bright probe provided by the FEG and by the reduced aberration coefficients of the strongly excited objective lens. The smaller specimen size required by in-lens instruments (about 1 cm, in comparison to 15 or 20 cm of a conventional SEM) doesn’t represent a serious limitation in the evaluation of semiconductor process techniques, where the demand of high resolution is continuosly increasing. In this field one of the more interesting applications, already described (1), is the observation of superlattice structures.In this note we report a comparison between secondary electron (SE) and backscattered electron (BSE) images of a GaAs / AlAs superlattice structure, whose cross section is reported in fig. 1. The structure consist of a 3 nm GaAs layer and 10 pairs of 7 nm GaAs / 15 nm AlAs layers grown on GaAs substrate. Fig. 2, 3 and 4 are SE images of this structure made with a JEOL JSM 890 SEM operating at an accelerating voltage of 3, 15 and 25 kV respectively. Fig. 5 is a 25 kV BSE image of the same specimen. It can be noticed that the 3nm layer is always visible and that the 3 kV SE image, in spite of the poorer resolution, shows the same contrast of the BSE image. In the SE mode, an increase of the accelerating voltage produces a contrast inversion. On the contrary, when observed with BSE, the layers of GaAs are always brighter than the AlAs ones , independently of the beam energy.

Mini-Scanning Electron Miscroscope Concept

1974 ◽  
Vol 32 ◽  
pp. 406-407
Author(s):  
Donald J. Evins ◽  
Robert J. Engle
Keyword(s):  
Electron Microscope ◽  
Depth Of Field ◽  
X Ray ◽  
Rapid Scan ◽  
Operational Characteristics ◽  
Electron Microscopes ◽  
The Cost ◽  
Scanning Electron Microscopes ◽  
Large Research ◽  
Scanning Electron

The scanning electron microscope has already established itself as one of the most useful instrument developments in recent years. The SEM provides 20 times greater useful magnifications and up to 500 times greater depth of-field than the best optical microscopes. Until the introduction of the Mini-SEM concept, the cost and complexity of SEM's has limited their use primarily to large research oriented laboratories.Design features, specifications, and operational characteristics will be reviewed. The Mini-Rapid Scan with resolution of 750Å will be described, along with the Mini-SEM with resolution of 150 to 200Å. Both of these are table top scanning electron microscopes. Various specimen stage options will be illustrated. Other accessories extending the SEM's versatility will be described, such as the energy dispersive x-ray system

Hitachi Scanning Electron Microscope

1968 ◽  
Vol 26 ◽  
pp. 374-375
Author(s):  
T. Fujiyasu ◽  
K. Hara ◽  
H. Tamura
Keyword(s):  
Optical Axis ◽  
Electrical Potential ◽  
Objective Lens ◽  
List Type ◽  
Type Number ◽  
Lens System ◽  
Mechanical Vibrations ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The demand for scanning electron microscopes is growing rapidly and exciting new fields of application have developed for this type of instrument. Hitachi, Ltd. has developed this type of instrument the details of which are described in this paper.A three stage demagnification lens system is used in the instrument. External magnetic and electrical disturbances and mechanical vibrations have been reduced.Aperture plates with different bore diameters are located above the condenser lens and deflection coil and the objective lens to reduce contamination by the fixed apertures in these lenses. An electromagnetic stigmator is provided in the objective lens field.The specimen stage permits X-, Y- and Z- axes movements as well as rotational tilting. The rotational tilting is such that its central axis is always coincident with the optical axis independent of the X-, Y- and Z- axes movements. Terminals are also provided which permit voltage measurements and to observe the electrical potential distribution of semi conductors.

Advances in the EM of Polymers

1981 ◽  
Vol 39 ◽  
pp. 334-337
Author(s):  
L. C. Sawyer
Keyword(s):  
Optical Microscopy ◽  
Small Group ◽  
Fiber Morphology ◽  
The Past ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Fine Structures ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Recent advances in Analytical Electxon Microscopy (AEM) have changed the methods by which microicopists study polymer and fiber morphology. As polymeric materialis play a major role in our way of living - clothing, shelter, fuel, chemicals - the interest has spread from a small group of theoretical physicists to the larger group of applications scientists. Until forty years ago, optical microscopy (OM) provided the only microicopical means of observing the morphology of materials. Then transmission electron microscopes (TEM) brought a new depth and resolution of fine structures not previously known. The methodology of preparing materials for TEM, ultramicrotomy and replication, are revealing but tedious and replete with artifacts. Bridging the gap between OM and TEM the scanning electron microscopes (SEM), in use over the past fifteen years, have provided easily available and interpretable surface images of fibers, fabrics, membranes, films and composites. Finally, the limited resolution of the SEM has been improved by the use of modern composite instruments known as analytical electron microscopes (AEM).

Series in Microscopy in Materials Science: Electron Microscopy in Heterogeneous Catalysis. P.L. Gai and E.D. Boyes. Series Editors: B. Cantor, M.J. Goringe, and J.A Eades. Institute of Physics Publishing, Bristol, England; 2003, 233 pages (Hardback). ISBN 0-7503-0809-5

2003 ◽  
Vol 9 (4) ◽  
pp. 368-368
Author(s):  
Hiroyasu Saka
Keyword(s):  
Electron Microscopy ◽  
Heterogeneous Catalysis ◽  
Materials Science ◽  
The Past ◽  
Dynamic Observation ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

This book deals with in situ dynamic observation and analysis of heterogeneous catalysis using environmental cells (EC) in transmission (TEM) and scanning electron microscopes (SEM). In general, it is based on outstanding and unique works carried out by the authors themselves over the past three decades, who pioneered this key enabling area of materials science.

Stereological Analysis Of Sem Images

1977 ◽  
Vol 35 ◽  
pp. 212-213
Author(s):  
H. S Schmiβer ◽  
R. A. Swensson
Keyword(s):  
Image Analysis ◽  
Three Dimensional ◽  
Quantitative Information ◽  
Quantitative Image Analysis ◽  
Sem Images ◽  
Detection Systems ◽  
The Past ◽  
Quantitative Image ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Development of new signal detection systems for STEREOSCAN scanning electron microscopes has greatly increased the applicability of quantitative image analysis to pictures obtained with an s.e.m. While quantitative image analysis has proven to be a powerful technique to draw quantitative information from pictures obtained from light microscopes as well as various other sources of images, the field of scanninq electron microscopy has largely been uncovered in the past.This was mainly due to the particular appearance of “normal” s.e.m. pictures. Exactly those features which make s.e.m. pictures easy to interpret intuitively an aesthetically attractive i.e. the pseudo three dimensional appearance made it virtually impossible to treat these images with the well known methods of electronic image analysis.

Condenser-objective lens SE microscopy: application for high - resolution imaging of cell membranes

1987 ◽  
Vol 45 ◽  
pp. 564-567
Author(s):  
R.P. Apkarian
Keyword(s):  
High Resolution ◽  
Primary Electron ◽  
Objective Lens ◽  
Beam Diameter ◽  
Contrast Imaging ◽  
Electron Sources ◽  
Recent Developments ◽  
Brightness Field ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Recent developments in high brightness field emission (FE) and LaB6 electron sources for scanning electron microscopes (SEM) equipped with condenser-objective lens specimen stages has resulted in the collection of secondary electron (SE) signals that contain unsurpassed high resolution topographic contrasts. High resolution low loss images were described for a condenser-objective lens SEM when SE contrasts were first being scrutinized. The low energy SE-I imaging mode contains contrasts generated by only specimen specific SE-I and II. The SE-I signal is produced by the primary electron beam interaction with the specimen surface before a scattering event occurs and can be best collected when SE-IIIs are eliminated and SE-IIs are suppressed. High resolution SE-I topographic contrasts include particle contrast (resolution of particles < 10 nm), relief contrast (imaging of very small contours), and edge brightness contrast (sum of beam diameter and SE range).

A Low Cost Configuration for Internetwork Telemicroscopy

2000 ◽  
Vol 6 (S2) ◽  
pp. 1146-1147
Author(s):  
D. W. Dorward
Keyword(s):  
Low Cost ◽  
Time Sharing ◽  
Still Images ◽  
Web Based ◽  
Input Devices ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
The Cost ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Advances in internetwork data transmission rates and reductions in the cost of imaging components and applications have facilitated real-time sharing of video, still images, and microscope operating systems with collaborators or observers at remote locations. Specialized direct and web-based systems for transmission electron microscopy have been described previously. However, in order to develop a generic and flexible means of sharing live images and data from light, scanning electron, and transmission electron microscope instruments, a telemicroscopy system was configured using readily available components and software that can be adapted for use with most common computer operating and networking systems.Figure 1 diagrams the general configuration used in our laboratory. Input devices can include inexpensive desktop digital or analog video cameras, specialized fast or slow scan CCD cameras, and the analog video-screen signal generated by scanning electron microscopes. For transmission through TCP/IP networks, analog signals must be digitized with a frame grabber card.

The Characterization of Nano Materials in the FE-SEM

2000 ◽  
Vol 6 (S2) ◽  
pp. 744-745
Author(s):  
Raynald Gauvin ◽  
Paula Horny
Keyword(s):  
Secondary Electron ◽  
Incident Electron Energy ◽  
Objective Lens ◽  
Type I ◽  
Nano Materials ◽  
Backscattered Electrons ◽  
Probe Diameter ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The observation of nano materials or nano phases is generally performed using Transmission Electron Microscopy (TEM) because conventional Scanning Electron Microscopes (SEM) do not have the resolution to image such small phases. Since the last decade, a new generation of microscopes is available on the market. These are the Field Emission Scanning Electron Microscope (FE-SEM) with a virtual secondary electron detector. The FE-SEM have a higher brightness allowing probe diameter smaller than 2.5 nm with incident electron energy, E0, below 5 keV. Furthermore, what gives FE-SEM outstanding resolution is the virtual secondary electron (SE) detector. The virtual SE detector is located above the objective lens and it is also named a through-the-lens (TTL) detector. Therefore, the SE images are mostly made up of all SE of type I and II, because those of type III, which are generated by the backscattered electrons in the chamber, are not collected.

scholarly journals Copper-Silver Nanohybrids: SARS-CoV-2 Inhibitory Surfaces

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1820
Author(s):  
Dina A. Mosselhy ◽  
Lauri Kareinen ◽  
Ilkka Kivistö ◽  
Kirsi Aaltonen ◽  
Jenni Virtanen ◽  
...  
Keyword(s):  
Public Transportation ◽  
Hot Spots ◽  
Public Place ◽  
Shopping Malls ◽  
Precise Control ◽  
The Past ◽  
Live Stock ◽  
Promising Application ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a severe health threat. The COVID-19 infections occurring in humans and animals render human-animal interfaces hot spots for spreading the pandemic. Lessons from the past point towards the antiviral properties of copper formulations; however, data showing the “contact-time limit” surface inhibitory efficacy of copper formulations to contain SARS-CoV-2 are limited. Here, we show the rapid inhibition of SARS-CoV-2 after only 1 and 5 min on two different surfaces containing copper-silver (Cu-Ag) nanohybrids. We characterized the nanohybrids’ powder and surfaces using a series of sophisticated microscopy tools, including transmission and scanning electron microscopes (TEM and SEM) and energy-dispersive X-ray spectroscopy (EDX). We used culturing methods to demonstrate that Cu-Ag nanohybrids with high amounts of Cu (~65 and 78 wt%) and lower amounts of Ag (~7 and 9 wt%) inhibited SARS-CoV-2 efficiently. Collectively, the present work reveals the rapid SARS-CoV-2 surface inhibition and the promising application of such surfaces to break the SARS-CoV-2 transmission chain. For example, such applications could be invaluable within a hospital or live-stock settings, or any public place with surfaces that people frequently touch (i.e., public transportation, shopping malls, elevators, and door handles) after the precise control of different parameters and toxicity evaluations.

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