Charge Contrast Imaging of Nonconductive Samples in the High-Vacuum Field Emission Scanning Electron Microscope

Scanning ◽  
2007 ◽  
Vol 29 (5) ◽  
pp. 230-237 ◽  
Author(s):  
Yuan Ji ◽  
Li Wang ◽  
Xueling Quan ◽  
Jingyong Fu ◽  
Yinqi Zhang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
High Vacuum ◽  
Vacuum Field ◽  
Contrast Imaging ◽  
Scanning Electron

Field emission scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 14-15
Author(s):  
R. Aihara ◽  
S. Saito ◽  
II. Kohinata ◽  
K. Ogura ◽  
H. Otsuji
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
Probe Diameter ◽  
Tungsten Single Crystal ◽  
Working Distance ◽  
Scanning Electron

A compact type field emission scanning electron microscope (JSM-F15) has recently been developed (Fig. 1). Moreover, due to the simplicity of the electron optical column and the automatically controlled ultra high vacuum system, a good quality and high resolution image can easily be obtained.The electron optical column, which is shown in Fig. 2, comprises a field emission gun, an electromagnetic lens, scanning coils, etc. The gun, which is composed of a field emitter, a wehnelt and an anode, is pre-aligned. The accelerating voltage is 15 kV and the emitter tip, made of tungsten single crystal, has a [310] orientation in the electron optical axis. The wehnelt is biased through a feedback circuit so as to maintain the emission current constant without varying the accelerating voltage.The electron probe current at the specimen surface is about 3 × 10-11 amp and the probe diameter is about 30Å at the working distance of 15 mm.

Use of platinum shadowing and magnetron sputter coating in an Oxford Cryotrans system to increase low temperature resolution of biological samples in a Hitachi field-emission Scanning Electron Microscope

1993 ◽  
Vol 51 ◽  
pp. 122-123
Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Alan Robins
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
High Vacuum ◽  
Water Ice ◽  
Temperature Observation ◽  
Sputter Coating ◽  
Magnetron Sputter ◽  
Scanning Electron

Previous studies in this laboratory have shown that the resolution of biological specimens could be increased at least two fold in a conventional as well as a field emission SEM by substituting high vacuum evaporation of Pt for standard sputter coating. Because the EMscope SP2000A Sputter Cryo System and the Oxford CT 1500 Cryotrans System, which were used in these experiments, employed standard sputter coating, Pt shadowing and C evaporation were carried out in a modified Denton DFE-3 freeze-etch module on a DV-503 high vacuum evaporator and the coated specimens were transferred to the cryostage (EMscope) or the prechamber (Oxford) of the cryosystem. Not only did this procedure require a high vacuum evaporator but as a result of a through air transfer into LN2, considerable contamination condensed on the surface of the specimen. Most of this contamination consisted of water ice that could be easily sublimed; however, other unidentifiable contaminants remained. To increase the versatility of the cryosystem, reduce surface contamination of the specimen and evaluate alternative coating procedures, Oxford Cryotrans Systems were equipped and tested with a Pt evaporator and a high resolution magnetron sputter head. Low temperature observation and evaluation of the coated specimens were performed in a Hitachi S4100 field emission scanning electron microscope.

Voltage contrast imaging with energy filtered signal in a field-emission scanning electron microscope

2020 ◽  
Vol 209 ◽  
pp. 112889 ◽  
Author(s):  
Yoichiro Hashimoto ◽  
Shuichi Takeuchi ◽  
Takeshi Sunaoshi ◽  
Yu Yamazawa
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Contrast Imaging ◽  
Voltage Contrast ◽  
Scanning Electron

Field Emission SEM Equipped With Noise Compensator

1973 ◽  
Vol 31 ◽  
pp. 302-303
Author(s):  
S. Saito ◽  
H. Todokoro ◽  
S. Nomura ◽  
T. Komoda
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Low Contrast ◽  
Probe Current ◽  
High Resolution Images ◽  
Scanning Electron

Field emission scanning electron microscope (FESEM) features extremely high resolution images, and offers many valuable information. But, for a specimen which gives low contrast images, lateral stripes appear in images. These stripes are resulted from signal fluctuations caused by probe current noises. In order to obtain good images without stripes, the fluctuations should be less than 1%, especially for low contrast images. For this purpose, the authors realized a noise compensator, and applied this to the FESEM.Fig. 1 shows an outline of FESEM equipped with a noise compensator. Two apertures are provided gust under the field emission gun.

Comparison of freeze-fractured yeast replicas using conventional TEM and low-voltage field-emission SEM

1989 ◽  
Vol 47 ◽  
pp. 74-75
Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Terrence W. Reilly
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Low Voltage ◽  
Objective Lens ◽  
Specimen Preparation ◽  
Lens System ◽  
Air Drying ◽  
Preparation Techniques ◽  
Scanning Electron

Although the first commercial scanning electron microscope (SEM) was introduced in 1965, the limited resolution and the lack of preparation techniques initially confined biological observations to relatively low magnification images showing anatomical surface features of samples that withstood the artifacts associated with air drying. As the design of instrumentation improved and the techniques for specimen preparation developed, the SEM allowed biologists to gain additional insights not only on the external features of samples but on the internal structure of tissues as well. By 1985, the resolution of the conventional SEM had reached 3 - 5 nm; however most biological samples still required a conductive coating of 20 - 30 nm that prevented investigators from approaching the level of information that was available with various TEM techniques. Recently, a new SEM design combined a condenser-objective lens system with a field emission electron source.

Universal ESEM

1993 ◽  
Vol 51 ◽  
pp. 786-787
Author(s):  
G.D. Danilatos
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Vacuum ◽  
Natural Extension ◽  
Necessary Condition ◽  
Environmental Scanning ◽  
Detection Systems ◽  
Small Gain ◽  
Detection Medium ◽  
Scanning Electron

The environmental scanning electron microscope (ESEM) has evolved as the natural extension of the scanning electron microscope (SEM), both historically and technologically. ESEM allows the introduction of a gaseous environment in the specimen chamber, whereas SEM operates in vacuum. One of the detection systems in ESEM, namely, the gaseous detection device (GDD) is based on the presence of gas as a detection medium. This might be interpreted as a necessary condition for the ESEM to remain operational and, hence, one might have to change instruments for operation at low or high vacuum. Initially, we may maintain the presence of a conventional secondary electron (E-T) detector in a "stand-by" position to switch on when the vacuum becomes satisfactory for its operation. However, the "rough" or "low vacuum" range of pressure may still be considered as inaccessible by both the GDD and the E-T detector, because the former has presumably very small gain and the latter still breaks down.

Mounting an individual submicrometer sized single crystal

1996 ◽  
Vol 211 (6) ◽  
Author(s):  
R. B. Neder ◽  
M. Burghammer ◽  
Th. Grasl ◽  
H. Schulz
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Single Crystal ◽  
Single Crystals ◽  
High Vacuum ◽  
Nanometer Resolution ◽  
Micro Manipulator ◽  
Scanning Electron

AbstractWe developed a new micro manipulator for mounting individual sub-micrometer sized single crystals within a scanning electron microscope. The translations are realized via a commercially available piezomicroscope, adapted for high vacuum usage and realize nanometer resolution. With this novel instrument it is routinely possible to mount individual single crystals with sizes down to 0.1

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