scholarly journals COMPARISON OF THE EFFICIENCY OF DIFFERENT DETECTORS OF THE SCANNING ELECTRONIC MICROSCOPE «MIRA-LMH» FOR STUDYING MICROSTRUCTURE OF NANOMATERIALS

2021 ◽  
pp. 250-262
Author(s):  
Дмитрий Сергеевич Кулешов ◽  
Андрей Владимирович Блинов ◽  
Анастасия Александровна Блинова ◽  
Мария Анатольевна Ясная ◽  
Давид Гурамиевич Маглакелидзе ◽  
...  
Keyword(s):  
Secondary Electron ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
High Sensitivity ◽  
Stöber Method ◽  
Electron Detector ◽  
Material Contrast ◽  
The Stöber Method ◽  
Working Distance ◽  
Scanning Electron

На первом этапе были синтезированы объекты исследования - диоксид кремния методом Штобера, где в качестве прекурсора использовали тетраэтоксисилан, и нанокомпозит ZnO - Au золь-гель методом с использованием в качестве прекурсора 2 - водного ацетата цинка. На втором этапе, микроструктуру и морфологию полученных образцов исследовали методом растровой электронной микроскопии на сканирующем электронном микроскопе «MIRA-LMH» фирмы «Tescan» с применением как классического детектора вторичных электронов, так и дополнительных детекторов - внутрилинзового детектора вторичных электронов и детектора отраженных электронов. В результате исследований установлено, что при использовании детектора вторичных электронов получаются изображения с топографическим контрастом и практически без шумов. При использовании внутрилинзового детектора вторичных электронов создаются изображения только материального контраста, без влияния рельефа поверхности. Также использование данного детектора позволило получить высококачественные изображения с большим разрешением на расстоянии от образца 5 мм. При использовании детектора отраженных электронов с рабочим расстоянием до образца 8 мм и увеличении разрешающей способности микроскопа, полученные изображения имеют низкий контраст границ, но представляют композиционную информацию с высокой чувствительностью. Таким образом, установлено, что внутрилинзовый детектор вторичных электронов, с рабочим расстоянием до образца 5 мм, является оптимальным для получения четких изображений микроструктры поверхности наноматериалов при многократном увеличении. At the first stage, the objects of study were synthesized - silicon dioxide by the Stober method, where tetraethoxysilane was used as a precursor, and a nanocomposite ZnO - Au by the sol-gel method using the aqueous zinc acetate dihydrate as a precursor. At the second stage, the microstructure and morphology of the obtained samples were investigated by scanning electron microscopy on a «MIRA-LMH» scanning electron microscope (Tescan company) using both a classical secondary electron detector and additional detectors - intralens secondary electron detector and back-scattered electrons detector. As a result of the research, it was found that when using the secondary electron detector, practically no noise images with topographic contrast are obtained. When using the intralens secondary electron detector, images of only material contrast are created, without the influence of the surface relief. Also, the use of this detector made it possible to obtain high-quality images with a high resolution at a distance of 5 mm from the sample. When using a back-scattered electrons detector with a working distance to the sample of 8 mm and increasing the resolution of the microscope, the resulting images have low border contrast, but represent compositional information with high sensitivity. Thus, it was found that the intralens secondary electron detector with a working distance of 5 mm to the sample is optimal for obtaining clear images of the microstructure of the surface of nanomaterials at multiple magnifications.

Ultra-high resolution SEMI-in-lens type FE-SEM, JSM-6320F, with strong magnetic-field lens with built-in secondary-electron detector

1994 ◽  
Vol 52 ◽  
pp. 484-485
Author(s):  
T. Miyokawa ◽  
H. Kazumori ◽  
S. Nakagawa ◽  
C. Nielsen
Keyword(s):  
High Resolution ◽  
Secondary Electron ◽  
Spherical Aberration ◽  
Incident Beam ◽  
Chromatic Aberration ◽  
Magnetic Flux Density ◽  
Objective Lens ◽  
Electron Detector ◽  
High Resolution Images ◽  
Working Distance

We have developed a strongly excited objective lens with a built-in secondary electron detector to provide ultra-high resolution images with high quality at low to medium accelerating voltages. The JSM-6320F is a scanning electron microscope (FE-SEM) equipped with this lens and an incident beam divergence angle control lens (ACL).The objective lens is so strongly excited as to have peak axial Magnetic flux density near the specimen surface (Fig. 1). Since the speciien is located below the objective lens, a large speciien can be accomodated. The working distance (WD) with respect to the accelerating voltage is limited due to the magnetic saturation of the lens (Fig.2). The aberrations of this lens are much smaller than those of a conventional one. The spherical aberration coefficient (Cs) is approximately 1/20 and the chromatic aberration coefficient (Cc) is 1/10. for accelerating voltages below 5kV. At the medium range of accelerating voltages (5∼15kV). Cs is 1/10 and Cc is 1/7. Typical values are Cs-1.lmm. Cc=l. 5mm at WD=2mm. and Cs=3.lmm. Cc=2.9 mm at WD=5mm. This makes the lens ideal for taking ultra-high resolution images at low to medium accelerating voltages.

Novel and Advanced Applications of the Low Vacuum and Environmental Scanning Electron Microscope (SEM)

1997 ◽  
Vol 3 (S2) ◽  
pp. 385-386 ◽  
Author(s):  
Brendan J. Griffin
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Secondary Electron ◽  
Electron Gun ◽  
Environmental Scanning ◽  
Electron Detector ◽  
Environmental Sem ◽  
Practical Sense ◽  
Advanced Applications ◽  
Scanning Electron

The environmental SEM is an extremely adaptive instrument, allowing a range of materials to be examined under a wide variety of conditions. The limitations of the instrument lie mainly with the restrictions imposed by the need to maintain a moderate vacuum around the electron gun. The primary effect of this has been, in a practical sense, the limited low magnification available. Recently this has been overcome by modifications to the final pressure limiting aperture and secondary electron detector (Fig.l). The modifications are simple and users should be brave in this regard.A variety of electron detectors now exist including various secondary, backscattered and cathodoluminescence systems (Figs 2-5). These provide an excellent range of options; the ESEM must be regarded as a conventional SEM in that a range of imaging options should be installed. In some cases, e.g. cathodoluminescence, the lack of coating provides an advantage unique to the low vacuum SEMs.

Effects of Electron-ion Recombination on Contrast in ESEM Images

2001 ◽  
Vol 7 (S2) ◽  
pp. 794-795
Author(s):  
M. Toth ◽  
B. L. Thiel ◽  
A. M. Donald
Keyword(s):  
Secondary Electron ◽  
Image Formation ◽  
Environmental Scanning ◽  
Operating Parameters ◽  
Ion Recombination ◽  
Conventional Models ◽  
Working Distance ◽  
Present Experimental Evidence ◽  
Scanning Electron

We present experimental evidence for the effects of electron-ion recombination on contrast formation in secondary electron (SE) images obtained using an environmental scanning electron microscope (ESEM). Inclusion of the effects of SE-ion recombination in the theory of ESEM image formation accounts for contrast reversal observed, under appropriate conditions, in SE images of conductors (ie, in the absence of localized specimen charging) and of insulators that exhibit localized charging. Previously unexplained dynamic contrast caused by temporal charging can be understood if both conventional models of the effects of charging on SE emission, and the proposed role of SEion recombination in ESEM image formation are accounted for.In an ESEM, the extent of charging exhibited by insulating specimens can be controlled by varying the type and pressure (P) of the imaging gas, and operating parameters that determine the extent to which the gas is ionized (eg, detector bias, VGSED, and working distance, WD).

Field Emission SEM with a Newly Developed FEGUN and Conical Strongly Excited Objective Lens

2000 ◽  
Vol 6 (S2) ◽  
pp. 764-765
Author(s):  
H. Kazumori ◽  
A. Yamada ◽  
M. Mita ◽  
T. Nokuo ◽  
M. Saito
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Secondary Electron ◽  
Objective Lens ◽  
Probe Current ◽  
Large Samples ◽  
Low Emission ◽  
Working Distance ◽  
Scanning Electron

A newly developed cold FE-GUN which enables to us to obtain large probe current and low emission noise, and conical strongly excited objective lens has been installed on the JSM-6700F Scanning Electron Microscope (SEM). In the range of accelerating voltages from 0.5 to 15kV, this instrument has got much better resolution as compared with in-lens type SEM (Ohyama et al 1986)(Fig. 1). We can obtain high-resolution secondary electron images with large samples (ex. 150mm ϕ×10mmH).Our old type objective lens (Kazumori et al 1994) has the limitation of working distance (WD), but the new lens enables us to work at very short WD at accelerating voltage of 15kV. As a result the spherical (Cs) and chromatic (Cc) aberration constants are 1.9mm and 1.7mm respectively at a WD of 3mm.In order to get large probe current, we increased emission current and got near the distance between the t ip of emi tter and the pr inciple plane of condenser lens.

Imaging thin and thick sections of biological tissue with the secondary electron detector in a field-emission scanning electron microscope

Scanning ◽  
2006 ◽  
Vol 19 (6) ◽  
pp. 387-395 ◽  
Author(s):  
William P. Wergin ◽  
Robert W. Yaklich ◽  
Stéphane Roym ◽  
David C. Joy ◽  
Eric F. Erbe ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Biological Tissue ◽  
Secondary Electron ◽  
Electron Detector ◽  
Scanning Electron

Recent Advances in Gaseous Detection Modes in the ESEM

1999 ◽  
Vol 5 (S2) ◽  
pp. 268-269
Author(s):  
T. A. Hardt ◽  
W. R. Knowles
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Secondary Electron ◽  
Large Field ◽  
Environmental Scanning ◽  
Electron Detector ◽  
Field Detection ◽  
Gaseous Environment ◽  
Detection Mode ◽  
Scanning Electron

The Environmental Scanning Electron Microscope, or ESEM, is the only class of SEM that can image in a gaseous environment that will maintain a sample in a fully wet state. The use of the patented Gaseous Secondary Electron Detector, or GSED, which amplifies the secondary electron signal with the gas, has allowed the ESEM to image a multitude of samples with true secondary contrast. Recently, several new modes of imaging in a gas have been developed and will allow further expansion of the capabilities of the ESEM.To maintain pressures in the ESEM up to 20 Torr (27 mbar), the use of multiple, differentially pumped apertures, is required. This can place a restriction on the low magnification range. In the large field detection mode, all magnification restrictions are removed. Magnifications as low as lOx may be achieved. This is similar to many conventional SEMs.

Resolution Limits of Secondary Electron Dopant Contrast in Helium Ion and Scanning Electron Microscopy

2011 ◽  
Vol 17 (4) ◽  
pp. 637-642 ◽  
Author(s):  
Mark Jepson ◽  
Xiong Liu ◽  
David Bell ◽  
David Ferranti ◽  
Beverley Inkson ◽  
...  
Keyword(s):  
Secondary Electron ◽  
Electrical Potential ◽  
Helium Ion ◽  
Resolution Limits ◽  
Contrast Mechanism ◽  
Material Contrast ◽  
Dopant Atoms ◽  
Scanning Electron

AbstractAs the miniaturization of semiconductor devices continues, characterization of dopant distribution within the structures becomes increasingly challenging. One potential solution is the use of the secondary electron signal produced in scanning electron (SEMs) or helium ion microscopes (HeIMs) to image the changes in electrical potential caused by the dopant atoms. In this article, the contrast mechanisms and resolution limits of secondary electron dopant contrast are explored. It is shown that the resolution of the technique is dependent on the extent of electrical potential present at a junction and that the resolution of dopant contrast can be improved in the HeIM after an in-situ plasma cleaning routine, which causes an oxide to form on the surface altering the contrast mechanism from electrical potential to material contrast.

Sign in / Sign up

Export Citation Format

Share Document