Development and Application of a New 300kv Omega-Filter Electron Microscope

2000 ◽  
Vol 6 (S2) ◽  
pp. 200-201
Author(s):  
Y. Bando ◽  
M. Mitome ◽  
Y. Kitami ◽  
K. Kurashima ◽  
T. Kaneyama ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Spatial Resolution ◽  
Imaging Plate ◽  
Medium Voltage ◽  
Probe Current ◽  
Probe Diameter ◽  
Probe Size ◽  
Characteristic Features ◽  
Lattice Resolution

It has been already pointed out that the medium voltage microscopes of 300kV to 400kV have some advantages in the analytical capabilities of EDS and EELS as compared to those of 200kV). The P/B ratios and the spatial resolution for the analysis will be improved with the increase of the accelerating voltages as well as lattice resolution. In order to improve the spatial resolution of inelastic filtered images, we have recently developed a new 300 kV omega-filter electron microscope with a field emission gun. In the paper, some characteristic features of the new microscope and its application results are described.The new microscope have a 300kV field emission gun, an omega-filter, EDS, digital STEM, a slow-scan CCD, an imaging plate and TV camera. Some characteristic features of the new microscope are summarized in Table 1. Based on a calculation of probe diameter as a function of probe current at 300kV in a Shottkey type gun with a brightness of 7xl08A/cm2sr and Cs of 0.6mm, a minimum probe size (FWHM) is estimated to be about 0.2nm (Fig. 1).

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.

The Observation of NBC Precipitates In Steels In The Nanometer Range Using A Field Emission Gun Scanning Electron Microscope

1997 ◽  
Vol 3 (S2) ◽  
pp. 1243-1244 ◽  
Author(s):  
Raynald Gauvin ◽  
Steve Yue
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Incident Electron Energy ◽  
Beam Diameter ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

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.

Ultrahigh-Vacuum Field-Emission Electron Microscope as Applied to Observation and Analysis of Crystal Surface

1997 ◽  
Vol 3 (S2) ◽  
pp. 597-598
Author(s):  
M. Takeguchi ◽  
T. Honda ◽  
Y. Ishida ◽  
M. Kersker ◽  
M. Tanaka ◽  
...  
Keyword(s):  
Field Emission ◽  
Crystal Surface ◽  
Ultrahigh Vacuum ◽  
Atomic Scale ◽  
Vacuum Field ◽  
In Situ Observation ◽  
Probe Size ◽  
Point To Point ◽  
Lattice Resolution ◽  
Reaction Processes

UHV(ultrahigh-vacuum) TEM has long been used as a powerful tool for studying crystal surfaces, particularly for both the direct imaging of the surface structure and for in-situ observation of surface reaction processes with atomic resolution.This paper reports a newly developed 200kV UHV TEM equipped with a field emission gun(FEG). The instrument is designed to obtain information about elemental or bonding states of surfaces in addition to observation of surface atomic structure with high contrast. Basic performances of the UHV FE-TEM includes a specimen vacuum of 2.0X10-8Pa, probe size less than 1.0nm Ø with 0.5nA probe current, point-to-point resolution of 0.21 nm, and a lattice resolution of 0.10nm.A UHV Energy Dispersive X-ray Spectrometer (EDS) originally developed by JEOL Ltd. and a Parallel Electron Energy Loss Spectrometer (PEELS) are attached to the UHV FE-TEM, which combined with a fine focused probe of 1.Onm Ø allows atomic scale spectroscopy of surfaces.

X-ray detection performance of a 300KV field-emission Analytical Electron Microscope

1993 ◽  
Vol 51 ◽  
pp. 250-251
Author(s):  
C. E. Lyman ◽  
J. I. Goldstein ◽  
D.B. Williams ◽  
D.W. Ackland ◽  
S. von Harrach ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Detection Performance ◽  
Electron Gun ◽  
X Rays ◽  
X Ray ◽  
Analytical Electron ◽  
Analytical Electron Microscope

A major goal of analytical electron micrsocopy (AEM) is to detect small amounts of an element in a given matrix at high spatial resolution. While there is a tradeoff between low detection limit and high spatial resolution, a field emission electron gun allows detection of small amounts of an element at sub-lOnm spatial resolution. The minimum mass fraction of one element measured in another is proportional to [(P/B)·P]-1/2 where the peak-to-background ratio P/B and the peak intensity P both must be high to detect the smallest amount of an element. Thus, the x-ray detection performance of an analytical electron microscope may be characterized in terms of standardized measurements of peak-to-background, x-ray intensity, the level of spurious x-rays (hole count), and x-ray detector performance in terms of energy resolution and peak shape.This paper provides measurements of these parameters from Lehigh’s VG Microscopes HB-603 field emission AEM. This AEM was designed to provide the best x-ray detection possible.

Facility Implementation and Comparative Performance Evaluation of Probe-Corrected TEM/STEM with Schottky and Cold Field Emission Illumination

2013 ◽  
Vol 19 (2) ◽  
pp. 487-495 ◽  
Author(s):  
Yan Xin ◽  
John Kynoch ◽  
Ke Han ◽  
Zhiyong Liang ◽  
Peter J. Lee ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Electron Microscope ◽  
Field Emission ◽  
Spatial Resolution ◽  
Energy Resolution ◽  
Transmission Electron Microscope ◽  
Thermal Field ◽  
Scanning Transmission Electron Microscope ◽  
Comparative Performance ◽  
Transmission Electron

AbstractWe report the installation and performance evaluation of a probe aberration-corrected high-resolution JEOL JEM-ARM200F transmission electron microscope (TEM). We provide details on construction of the room that enables us to obtain scanning transmission electron microscope (STEM) data without any evident distortions/noise from the external environment. The microscope routinely delivers expected performance. We show that the highest STEM spatial resolution and energy resolution achieved with this microscope are 0.078 nm and 0.34 eV, respectively. We report a direct comparative evaluation of the performance of this microscope with a Schottky thermal field-emission gun versus a cold field-emission gun. Cold field-emission illumination improves spatial resolution of the high current probe for analytical spectroscopy, the TEM information limit, and the electron energy resolution compared to the Schottky thermal field-emission source.

Variation With Voltage of Probe Current in the Scanning Electron Microscope

1972 ◽  
Vol 30 ◽  
pp. 420-421
Author(s):  
V. E. Cosslett
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Spherical Aberration ◽  
Electron Source ◽  
Operating Voltage ◽  
Probe Current ◽  
Probe Diameter ◽  
Maximum Current ◽  
Scanning Electron

As the operating voltage Vp of a scanning electron microscope is raised, with an electron source of given emission brightness βE, the current delivered into the probe will increase. The extent of the increase will depend on whether it is the Gaussian probe diameter dG or the total probe diameter dT (determined by the lens aberrations) that is kept constant. It will also depend on whether the probe is limited by spherical aberration alone or also by diffraction.If the Gaussian probe diameter is constant the maximum current imax into a diffraction limited probe is found by setting the diameter of the disc of least confusion due to spherical aberration dS equal to the diameter of the Airy diffraction disc dD.

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.

Sign in / Sign up

Export Citation Format

Share Document