The JSM-890 ultra high resolution Scanning Electron Microscope

Author(s):  
M. Kersker ◽  
C. Nielsen ◽  
H. Otsuji ◽  
T. Miyokawa ◽  
S. Nakagawa

Historically, ultra high spatial resolution electron microscopy has belonged to the transmission electron microscope. Today, however, ultra high resolution scanning electron microscopes are beginning to challenge the transmission microscope for the highest resolution.To accomplish high resolution surface imaging, not only is high resolution required. It is also necessary that the integrity of the specimen be preserved, i.e., that morphological changes to the specimen during observation are prevented. The two major artifacts introduced during observation are contamination and beam damage, both created by the small, high current-density probes necessary for high signal generation in the scanning instrument. The JSM-890 Ultra High Resolution Scanning Microscope provides the highest resolution probe attainable in a dedicated scanning electron microscope and its design also accounts for the problematical artifacts described above.Extensive experience with scanning transmission electron microscopes lead to the design considerations of the ultra high resolution JSM- 890.

Author(s):  
Edward Coyne

Abstract This paper describes the problems encountered and solutions found to the practical objective of developing an imaging technique that would produce a more detailed analysis of IC material structures then a scanning electron microscope. To find a solution to this objective the theoretical idea of converting a standard SEM to produce a STEM image was developed. This solution would enable high magnification, material contrasting, detailed cross sectional analysis of integrated circuits with an ordinary SEM. This would provide a practical and cost effective alternative to Transmission Electron Microscopy (TEM), where the higher TEM accelerating voltages would ultimately yield a more detailed cross sectional image. An additional advantage, developed subsequent to STEM imaging was the use of EDX analysis to perform high-resolution element identification of IC cross sections. High-resolution element identification when used in conjunction with high-resolution STEM images provides an analysis technique that exceeds the capabilities of conventional SEM imaging.


1981 ◽  
Vol 48 (1) ◽  
pp. 55-73
Author(s):  
J.H. Temmink ◽  
H. Spiele

Normal 3T3 cells were exposed to vinblastine and cytochalasin B in an attempt to correlate the morphological changes of the cell surface as seen in the scanning electron microscope with ultrastructural changes of the cytoskeletal elements as seen in critical-point-dried cells in the transmission electron microscope. Special attention was given to the changes in the cytoplasmic domains distinguished in a previous paper. Cytochalasin B primarily affects the ultrastructure of the cytocortical domain by inducing the formation of condensation foci on the cytoplasmic material. Vinblastine not only induces the depolymerization of microtubules and the perinuclear concentration of intermediate filaments, but it also causes the disappearance of stress fibres from the cortical cytoplasm and the widening of the cytocortex at the expense of the endoplasmic domain. These results support the hypothesis that the differentiation in ultrastructural domains is dependent on the spreading of the cells and their adhesion to substrate.


1997 ◽  
Vol 3 (S2) ◽  
pp. 1243-1244 ◽  
Author(s):  
Raynald Gauvin ◽  
Steve Yue

The observation of microstructural features smaller than 300 nm 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 early 1990’s, a new generation of microscopes is now available on the market. These are the Field Emission Gun Scanning Electron Microscope with a virtual secondary electron detector. The field emission gun gives a higher brightness than those obtained using conventional electron filaments allowing enough electrons to be collected to operate the microscope with incident electron energy, E0, below 5 keV with probe diameter smaller than 5 nm. At 1 keV, the electron range is 60 nm in aluminum and 10 nm in iron (computed using the CASINO program). Since the electron beam diameter is smaller than 5 nm at 1 keV, the resolution of these microscopes becomes closer to that of TEM.


Author(s):  
P. S. Ong ◽  
C. L. Gold

Transmission electron microscopes (TEM) have the capability of producing an electron spot (probe) with a diameter equal to its resolving power. Inclusion of the required scanning system and the appropriate detectors would therefore easily convert such an instrument into a high resolution scanning electron microscope (SEM). Such an instrument becomes increasingly useful in the transmission mode of operation since it allows the use of samples which are considered too thick for conventional TEM. SEM accessories now available are all based on the use of the prefield of the objective lens to focus the beam. The lens is operated either as a symmetrical Ruska lens or its asymmetrical version. In these approaches, the condensor system of the microscope forms part of the reducing optics and the final spot size is usually larger than 20Å.


Author(s):  
Oliver C. Wells ◽  
P.C. Cheng

In this discussion the words “high resolution imaging” of a solid sample in the scanning electron microscope (SEM) mean that details can be resolved that are considerably smaller than the penetration depth of the incident electron beam (EB) into the specimen. “Atomic resolution” in either the transmission electron microscope (TEM) or scanning transmission electron microscope (STEM) means that columns of atoms are resolved.Image contrasts in the backscattered electron (BSE) image are strongly affected by the specimen tilt and by the position and energy sensitivity of the BSE detector. The expression “BSE image” generally implies that the specimen is normal to the beam and the detector is above it. This shows compositional variations in the specimen with a spatial resolution limited by the spreading of the EB during the initial stages of penetration. This is similar in basic principle to the Z-Contrast method in the STEM that shows atomic resolution from a thinned single crystal mounted in the magnetic field of the focusing lens.


2001 ◽  
Vol 7 (S2) ◽  
pp. 822-823
Author(s):  
Stephen K. Chapman

I was trained as a transmission electron microscope engineer in the mid 1960s. I took resolution tests at least once each year and calibrated all of the microscopes that I attended, it was considered a standard procedure for those maintaining an instrument. Moving into the scanning electron microscope field in the mid 1970s it was natural to carry this practice over to that instrument, but in those days this was considered to be extreme. Now, as a consultant in electron microscopy, I routinely carry out SEM resolution, magnification calibration and contamination rate tests on the instruments that I use. I train operators in the role of preventative maintenance and encourage them to know as much as possible about their instruments as this increases their ability to fault find and maintain their own instruments.Resolution - in many laboratories most tungsten hairpin instruments are set up for extended filament life rater than for high resolution.


2019 ◽  
Vol 26 (08) ◽  
pp. 1950047
Author(s):  
JIANING LI ◽  
MOLIN SU ◽  
LIWEI ZHANG

The composites were obtained by the argon-arc cladding (AAC) of the Deloro22-Si3N4-Fe pre-placed powders on a TA1 titanium alloy substrate, which improved the wear resistance of the substrate. Such composites were investigated by means of the scanning electron microscope (SEM), the microscope and the high resolution transmission electron microscope (HRTEM). The results indicated that the amorphous phases were produced in such AAC composites, increasing the wear resistance. With addition of Y2O3, lots of the micro/nanoscale particles were formed, which further improved the wear resistance of such AAC composites.


Author(s):  
P. S. D. Lin ◽  
A. V. Crewe

In contrast to optical and transmission electron microscopes, which probe the interior, the scanning electron microscope usually only reveals the exterior structure of the specimen to the biologist. This is due both to the collection of secondary electrons as signal and to the practice of coating the specimen with various heavy, noble metals.Taking advantage of their penetrating power, one can use backscattered electrons to study the interior structure of the biological specimen in a scanning electron microscope. Here a block of specimen is first stained by means similar to those practiced in transmission electron microscopy. Then a coating of carbon is applied to supress the undesirable specimen charge-up. Although the resolution in this mode will be degraded by electron-atom scattering events, this approach promises to yield more histochemical information than studying merely the topography of the specimen.


2008 ◽  
Vol 600-603 ◽  
pp. 55-58
Author(s):  
Mamoru Imade ◽  
Takashi Ogura ◽  
Masahiro Uemura ◽  
Fumio Kawamura ◽  
Masashi Yoshimura ◽  
...  

We have achieved the first successful growth of 2H-SiC single crystals using the C-Li-Si melt system. Li-Si melt, whose melting point is lower than 1000 oC, was chosen because the 2H-SiC polytype is more stable at lower temperatures than other polytypes such as 3C-, 4H-, and 6H-SiC. Many hexagonal-shaped crystals of approximately 100 m in diameter were observed via a scanning electron microscope (SEM). A high resolution transmission electron microscope (HR-TEM) lattice image of the grown crystals showed a periodical structure with A-B stacking along the <0001> direction. These results indicated that the Li-based flux was useful for growing bulk 2H-SiC single crystals.


Sign in / Sign up

Export Citation Format

Share Document