SEM image sharpness analysis

1996 ◽  
Vol 54 ◽  
pp. 142-143
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Quantitative Information ◽  
Primary Electron ◽  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Frequency Changes ◽  
Electron Microscopes ◽  
Scanning Electron

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.

scholarly journals SEM Image Sharpness Analysis

1996 ◽  
Vol 4 (8) ◽  
pp. 18-19
Author(s):  
M.T. Postek ◽  
A.E. Vladar
Keyword(s):  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Electron Microscopes ◽  
Automated Scanning ◽  
Automated Instrument ◽  
Scanning Electron Microscopes ◽  
Day By Day ◽  
Scanning Electron ◽  
Semiconductor Production

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at IMIST. The fundamentals and results are discussed in this paper.

Field of View and Image Distortion : A Review of Low Magnification Imaging In the Environmental and Conventional Scanning Electron Microscopes (SEM)

1997 ◽  
Vol 3 (S2) ◽  
pp. 1193-1194
Author(s):  
Brendan J. Griffin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Of View ◽  
Depth Of Field ◽  
Aperture Size ◽  
Sem Image ◽  
Electron Microscopes ◽  
Working Distance ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Most scanning electron microscopy is performed at low magnification; applications utilising the large depth of field nature of the SEM image rather than the high resolution aspect. Some environmental SEMs have a particular limitation in that the field of view is restricted by a pressure limiting aperture (PLA) at the beam entry point of the specimen chamber. With the original ElectroScan design, the E-3 model ESEM utilised a 500 urn aperture which gave a very limited field of view (∼550um diameter at a 10mm working distance [WD]). An increase of aperture size to ∼lmm provided an improved but still unsatisfactory field of view. The simplest option to increase the field of view in an ESEM was noted to be a movement of the pressure and field, limiting aperture back towards the scan coils1. This approach increased the field of view to ∼2mm, at a 10mm WD. A commercial low magnification device extended this concept and indicated the attainment of conventional fields of view.

Method of improving image sharpness for annular-illumination scanning electron microscopes

2016 ◽  
Vol 55 (6S1) ◽  
pp. 06GD02 ◽  
Author(s):  
Momoyo Enyama ◽  
Koichi Hamada ◽  
Muneyuki Fukuda ◽  
Hideyuki Kazumi
Keyword(s):  
Image Sharpness ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The petrosal and inner ear of Herpetocetus sp. (Mammalia: Cetacea) and their implications for the phylogeny and hearing of archaic mysticetes

1996 ◽  
Vol 70 (6) ◽  
pp. 1045-1066 ◽  
Author(s):  
Jonathan H. Geisler ◽  
Zhexi Luo
Keyword(s):  
North Carolina ◽  
Inner Ear ◽  
High Frequency ◽  
Phylogenetic Trees ◽  
Computer Graphic ◽  
Low Frequency ◽  
Spherical Shape ◽  
Quantitative Information ◽  
Serial Sectioning ◽  
Gray Whales

This paper describes the petrosal (periotic) and the inner ear of Herpetocetus sp., an archaic mysticete whale (Mysticeti, Mammalia) from the Yorktown Formation (Pliocene) of North Carolina, USA. Parsimony analysis of 28 petrosal characters of Herpetocetus sp. and 11 other cetacean taxa supports the monophyly of mysticetes and the division of odontocetes and mysticetes. The in-group taxa of this analysis are: Herpetocetus, Parietobalaena, Pelocetus, Balaenidae, Eschrichtius, and Balaenopteridae. Odontocetes and the archaeocete Zygorhiza were used as successive outgroups to root phylogenetic trees and to establish character polarities. Among the modern mysticetes, the Balaenopteridae (rorquals) and the Eschrichtiidae (gray whales) are more closely related to each other than either is to the Balaenidae (bowhead and right whales). Several Miocene “cetotheriid” mysticetes and balaenids share some resemblance in the petrosal, suggesting their affinities. Quantitative information of the inner ear of Herpetocetus sp. was obtained by serial sectioning and computer graphic reconstruction. Herpetocetus sp. is much less developed than odontocetes in the cochlear structures that are crucial for high frequency hearing. Some cochlear structures in this fossil mysticete resemble more closely the non-echolocating modern mysticetes than early fossil toothed whales, indicating a possible specialization in low frequency hearing. This suggests that the archaic mysticetes of the Miocene and Pliocene did not have high frequency hearing necessary for echolocation. Herpetocetus sp. is similar to modern mysticetes but different from odontocetes in the spherical shape of the vestibule.

scholarly journals ANALISIS SUSEPTIBILITAS MAGNETIK TANAH LAPISAN ATAS SEBAGAI INDIKATOR BENCANA LONGSOR DI BUKIT SULA KECAMATAN TALAWI KOTA SAWAHLUNTO

2018 ◽  
Vol 15 (2) ◽  
pp. 112
Author(s):  
Arif Budiman ◽  
Dwi Puryanti ◽  
Febri Naldi
Keyword(s):  
Magnetic Susceptibility ◽  
High Frequency ◽  
Low Frequency ◽  
Magnetic Minerals ◽  
Average Value ◽  
Rain Drop ◽  
Space Range ◽  
Test Result ◽  
Scanning Electron

Landslide is a disaster that can harm properties and souls. Losses due to landslide can be minimized if there are known signs of landslide.. In this research, the landslide indicator is known through the analysis of the magnetic susceptibility of topsoil. This research is a case study conducted at Bukit Sula, Talawi District, Sawahlunto City.Soil samples were taken from two locations in Sula Hill, which are vegetated location (location A) and unvegetated location (location B). This research’s samples took with downward vertical  of each 100 m was taken with a space range of 5 m, so that is obtained 21 sampling points at each of these locations. Measurement of magnetic susceptibility value using Bartington Magnetic Susceptibility Meter measured at two frequencies, namely low frequency of 0.465 kHz (χLF) and high frequency of 4.65 kHz (χHF). At location A the obtained average value of χLF is 804.05×10-8 m3kg-1while the average value of χHF is 804.25×10-8 m3kg-1. At location B the obtained average value of χLF is 9.85×10-8 m3kg-1, while the average value of χHF is 9.64×10-8 m3kg-1. XRF test result showed that magnetic minerals in samples at both locations a hematit (Fe2O3). Based on the comparison of susceptibility value and concentration of hematite and quartz minerals between sample of location A and location B, it can be said that location B has been eroded. Based on the presence of superparamagnetic grain, the samples taken from location B have finer grains than the samples at location A. Scanning Electron Microscope (SEM) also shows that sample B has finer grains than the sample B.  These are because location B is an area without vegetation, causing rain drop directly into the soil and can decrease the level of soil grain attachment. Therefore, location B more likely occurred landslide than location A.

Contrast and Resolution in Scanning Electron Microscopes

1967 ◽  
Vol 25 ◽  
pp. 256-257
Author(s):  
Shizuo Kimoto ◽  
Hiroshi Hashimoto ◽  
Kiyoshi Mase
Keyword(s):  
Secondary Electron ◽  
Primary Electron ◽  
Secondary Electron Image ◽  
Scattered Electron ◽  
Secondary Electrons ◽  
Backscattered Electrons ◽  
Electron Image ◽  
Backscattered Electron ◽  
Electron Microscopes ◽  
Scanning Electron

In scanning electron microscopy, secondary and backscattered electrons play a most important role. When considering these two forms of signal source, it is necessary to treat them separately on the basis of contrast and resolution, since their production processes and energies are different. In practice, the electrons detected by the secondary electron detector consist of secondary electrons excited by a primary electron probe, those excited by backscattered electrons in the specimen and secondary electrons liberated from the specimen's environmental parts during backscattered electron bombardment. Consequently, it is difficult to completely eradicate the effect of backscattered electrons upon the secondary electron image. This paper presents information in regards to the differences in contrast and resolution between the secondary and back- scattered electron image under the condition of optimum secondary/backscattered electron separation. First, it was shown how secondary electron image contrast is affected by secondary electrons liberated by backscattered electrons.

Environmental Variability and Settlement Changes on the Pajarito Plateau, New Mexico

1991 ◽  
Vol 56 (2) ◽  
pp. 315-332 ◽  
Author(s):  
Janet D. Orcutt
Keyword(s):  
New Mexico ◽  
High Frequency ◽  
Environmental Variability ◽  
Low Frequency ◽  
Pajarito Plateau ◽  
Poor Understanding ◽  
Frequency Changes ◽  
Using Data ◽  
Settlement Changes ◽  
Northern Rio Grande

Recent studies have shown a relation between low- and high-frequency environmental variability and aspects of culture. This paper uses low-frequency alluvial and hydrological changes on the Colorado Plateaus and high-frequency changes in moisture availability for the northern Rio Grande between A.D. 1150 and A.D. 1600 to derive expectations for changes in settlement organization on the Pajarito Plateau. The expectations are evaluated using data on the distribution of population and field houses in elevation zones. Changes in population size and aggregation also are reviewed. Low-frequency processes especially appear to have played a role in settlement change until A.D. 1450. After this date, settlement does not conform to expectations. Reasons for this are suggested, including a poor understanding of low- frequency processes, conflict, and human-induced environmental degradation.

Development of NMIJ CRM 5207-a tungsten dot-array for the image sharpness evaluation in scanning electron microscopy – structure evaluation and determination of dot-pitch

Microscopy ◽  
2020 ◽  
Vol 69 (6) ◽  
pp. 360-370
Author(s):  
Kazuhiro Kumagai ◽  
Akira Kurokawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Expanded Uncertainty ◽  
Image Sharpness ◽  
Sem Image ◽  
Sharpness Measurement ◽  
Derivative Method ◽  
Structure Evaluation ◽  
Scanning Electron

Abstract We have developed a new certified reference material (CRM) for image sharpness evaluation and magnification calibration for scanning electron microscopy (SEM). Designed to be suitable for the image sharpness evaluation by the derivative method, the CRM has nanoscale tungsten dot-array structure fabricated on silicon substrate, which gives steep contrast transition from the dot to the substrate in SEM image. The pitch of the dot-array was SI-traceably measured as a specified value with relative expanded uncertainty ($k=2$) of ~1.3%, which can be utilized for the magnification calibration of SEM. Since specimens, as one of the image formation parameters, easily affect image sharpness value, our CRM, as a ‘pinned specimen’, will play an important role to achieve robust and stable image sharpness measurement system.

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