Resolution and measurement in the scanning electron microscope

1987 ◽  
Vol 45 ◽  
pp. 534-537 ◽  
Author(s):  
Michael T. Postek
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Engineering Design ◽  
Resolving Power ◽  
Practical Applications ◽  
Instrument Resolution ◽  
Accurate Definition ◽  
Definition Of ◽  
Scanning Electron ◽  
Better Than

The term ultimate resolution or resolving power is the very best performance that can be obtained from a scanning electron microscope (SEM) given the optimum instrumental conditions and sample. However, as it relates to SEM users, the conventional definitions of this figure are ambiguous. The numbers quoted for the resolution of an instrument are not only theoretically derived, but are also verified through the direct measurement of images on micrographs. However, the samples commonly used for this purpose are specifically optimized for the measurement of instrument resolution and are most often not typical of the sample used in practical applications.SEM RESOLUTION. Some instruments resolve better than others either due to engineering design or other reasons. There is no definitively accurate definition of how to quantify instrument resolution and its measurement in the SEM.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

The Determination and Application of the Point Spread Function in the Scanning Electron Microscope

2018 ◽  
Vol 24 (4) ◽  
pp. 396-405 ◽  
Author(s):  
Matthew D. Zotta ◽  
Mandy C. Nevins ◽  
Richard K. Hailstone ◽  
Eric Lifshin
Keyword(s):  
Spatial Distribution ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Beam Current ◽  
Beam Shape ◽  
Practical Applications ◽  
Energy Beam ◽  
Working Distance ◽  
Scanning Electron

AbstractA method is presented to determine the spatial distribution of electrons in the focused beam of a scanning electron microscope (SEM). Knowledge of the electron distribution is valuable for characterizing and monitoring SEM performance, as well as for modeling and simulation in computational scanning electron microscopy. Specifically, it can be used to characterize astigmatism as well as study the relationship between beam energy, beam current, working distance, and beam shape and size. In addition, knowledge of the distribution of electrons in the beam can be utilized with deconvolution methods to improve the resolution and quality of backscattered, secondary, and transmitted electron images obtained with thermionic, FEG, or Schottky source instruments. The proposed method represents an improvement over previous methods for determining the spatial distribution of electrons in an SEM beam. Several practical applications are presented.

Spot Electron-Beam Lithography as a Novel Method of High Resolution Pattern Nanofabrication

2014 ◽  
Vol 215 ◽  
pp. 459-461
Author(s):  
Alexander S. Samardak ◽  
Margarita V. Anisimova ◽  
Alexey V. Ognev ◽  
Vadim Yu. Samardak ◽  
Liudmila A. Chebotkevich
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Electron Beam Lithography ◽  
The Novel ◽  
Practical Applications ◽  
Novel Method ◽  
20 Nm ◽  
Scanning Electron

We present a novel method of pattern nanofabrication with high resolution and small shape defects using the traditional electron-beam lithography (EBL) or only a scanning electron microscope (SEM). Our method of Spot EBL is extremely fast, highly scalable on big areas, capable of sub-20 nm resolution and fabrication of polymer patterns with complicated shapes. We show the nanostructure images fabricated by Spot EBL and propose practical applications of the novel method.

Voltage and Dopant Concentration Measurements of Semiconductors using a Band-Pass Toroidal Energy Analyzer Inside a Scanning Electron Microscope

2015 ◽  
Vol 21 (4) ◽  
pp. 910-918 ◽  
Author(s):  
Avinash Srinivasan ◽  
Anjam Khursheed
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Dopant Concentration ◽  
High Signal ◽  
Energy Analyzer ◽  
Order Of Magnitude ◽  
Band Pass ◽  
Concentration Measurements ◽  
Scanning Electron ◽  
Better Than

AbstractThis paper presents experimental results obtained from a scanning electron microscope (SEM) second-order focusing toroidal electron energy analyzer attachment. The results demonstrate that the analyzer can be used to obtain high signal-to-noise voltage and dopant concentration measurements on semiconductors in the presence of different electric field conditions at the sample. The experimentally calculated relative error of measurement typically varies from 31 to 63, corresponding to secondary electron (SE) signal mean shifts of 9–18 mV. The millivolt accuracy of these results is over one order of magnitude better than earlier quantitative dopant concentration measurements made by a retarding field analyzer.

scholarly journals Preparo inicial em periodontia: avaliações perfilométricas e microscópias pós-remoção de excesso cervicais de restaurações

2021 ◽  
pp. 73-80
Author(s):  
Raul G. Caffesse ◽  
José D. Freitas Vale
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Class Ii ◽  
Measuring Instrument ◽  
Combined Use ◽  
The Mean ◽  
Amalgam Restorations ◽  
Scanning Electron ◽  
Better Than

Forty recently extracted teeth with Class II amalgam restorations with overhangs were divided in four groups of ten teeth each. The overhangs were removed using one of the following instruments in each gruop: trimmer, chisel, surgical blade and reciprocating.motor.driven diamond tip. Instrumentation was performed until no irregularity could be detected clinically with a nº 3 explorer. The tooth.amalgam interfaces were examined by combined use of a surface measuring instrument and a scanning electron microscope. Four tracings from each specimen were recorded and the vertical discrepancy at the tooth.restoration interfaces measured. The mean score for tooth was determined, and the results were photographed aí 140 magnification with the SEM. The results indicated that all instruments tested were effective in removing overhangs, since none of the discrepancies registered after instrumenntation exceeded 4 Um. The surgical blade, and especially the reciprocting-motor.driven diamond tip eliminated overhangs better than the chisel. Both SEM photographs and the profilometric tracing revealed gaps at the tooth amalgam interface, rancing from 10 t o 50 Um in width.

Scanning Microscopy of Thin Biological Specimens

1969 ◽  
Vol 27 ◽  
pp. 48-49
Author(s):  
A. V. Crewe ◽  
J. Wall
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Scanning Microscopy ◽  
Resolving Power ◽  
Electron Current ◽  
Scanning Electron ◽  
Transmission Microscope

We have recently improved our scanning electron microscope to a level that point resolution of 5 Å or so is possible. The electron current in the focused spot is about 10-10 amps so that good pictures can be obtained with a 10 sec exposure and the highest quality pictures can be obtained in 100 sec.The resolving power of this microscope is now comparable to that in a conventional transmission microscope for thin biological specimens and it is therefore of value to compare micrographs taken on the two types of instrument.

scholarly journals Evaluating the Emergence and Biochemical Changes of Primed Seeds in Proso Millet (Panicum miliaceum L.)

2019 ◽  
pp. 1-7
Author(s):  
R. Sridevi ◽  
V. Manonmani
Keyword(s):  
Cell Proliferation ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Pseudomonas Fluorescens ◽  
Biochemical Parameters ◽  
Free Sugars ◽  
Proso Millet ◽  
Scanning Electron ◽  
Better Than

The present study aimed in exploring the performance of primed seeds in enhancing the quality of proso millet. The primed seeds along with nonprimed seeds were evaluated for emergence, cell proliferation in radicle cells using scanning electron microscope and biochemical parameters. Seeds primed with Pseudomonas fluorescens 20% possessing higher germination and anatomical changes observed through scanning electron microscope revealed more cell proliferation which was found to show rapid cell elongation and cell division of the radicle when compared to nonprimed seeds. The biochemical causes responsible for higher invigorative effect were identified as enhanced enzyme activity recorded through α-amylase content, dehydrogenase activity, protein content, lipase activity, antioxidative enzymes like catalase activity, peroxidase activity and superoxide dismutase with lower electrical conductivity, free amino acid and free sugars of the seed leachate. It is concluded in this study that primed seeds of Pseudomonas fluorescens 20% performed better than other treatments through their exhibition of higher emergence, more cell proliferation and enhanced biochemical parameters.

Spatial Resolution of SEM Signals

1972 ◽  
Vol 30 ◽  
pp. 436-437
Author(s):  
H. Soezima
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Primary Electron ◽  
Resolving Power ◽  
X Rays ◽  
Primary Electron Beam ◽  
Scanning Electron Microscope Analysis ◽  
Electron Microscope Analysis ◽  
Scanning Electron

There are few investigations discussed on resolution of the signals as spatial resolving power, at the scanning electron microscope analysis. There remains misunderstanding that better resolution is obtained only by making a primary electron beam diameter small. At the scanning electron microscope analysis, there are such signals as secondary electron, back scattered electron, absorbed electron, transmitted electron, auger electron, cathode luminescence and X-rays. The spatial resolutions of these signals are effected not only by primary electron diameter but also by accelerating voltage, sample density, electro conductivity of the sample, surface condition of the sample, relative position among the primary electron optics, sample and detection system, energy of the signals, potential and magnetic distribution, and current density distribution of primary electron beam.Some examples of the X-rays, that have the poorest resolving power in the signals, are shown below.

scholarly journals Twisting of Fibers Balancing the Gel–Sol Transition in Cellulose Aqueous Suspensions

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 873 ◽  
Author(s):  
Dmitry Zlenko ◽  
Sergey Nikolsky ◽  
Alexander Vedenkin ◽  
Galina Politenkova ◽  
Aleksey Skoblin ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Cellulose Fibers ◽  
Film Production ◽  
3D Scaffold ◽  
Friction Forces ◽  
Practical Applications ◽  
Exponential Increase ◽  
The Individual ◽  
Scanning Electron

Cellulose hydrogels and films are advantageous materials that are applied in modern industry and medicine. Cellulose hydrogels have a stable scaffold and never form films upon drying, while viscous cellulose hydrosols are liquids that could be used for film production. So, stabilizing either a gel or sol state in cellulose suspensions is a worthwhile challenge, significant for the practical applications. However, there is no theory describing the cellulose fibers’ behavior and processes underlying cellulose-gel-scaffold stabilizing. In this work, we provide a phenomenological mechanism explaining the transition between the stable-gel and shapeless-sol states in a cellulose suspension. We suppose that cellulose macromolecules and nanofibrils under strong dispersing treatment (such as sonication) partially untwist and dissociate, and then reassemble in a 3D scaffold having the individual elements twisted in the nodes. The latter leads to an exponential increase in friction forces between the fibers and to the corresponding fastening of the scaffold. We confirm our theory by the data on the circular dichroism of the cellulose suspensions, as well as by the direct scanning electron microscope (SEM) observations and theoretical assessments.

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