A Stable High-Brightness Electron Gun with Zr/W-tip for Nanometer Lithography. I. Emission Properties in Schottky- and Thermal Field-Emission Regions

1985 ◽  
Vol 24 (Part 1, No. 6) ◽  
pp. 766-771 ◽  
Author(s):  
Norihiko Samoto ◽  
Ryuichi Shimizu ◽  
Hatsujiro Hashimoto ◽  
Nobuaki Tamura ◽  
Kenji Gamo ◽  
...  
Keyword(s):  
Field Emission ◽  
Thermal Field ◽  
Electron Gun ◽  
High Brightness ◽  
Emission Properties

Single-Crystal LaB6 as Thermal Field Emitter for Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 196-197
Author(s):  
Ken Harada ◽  
Haruto Nagata ◽  
Ryuichi Shimizu ◽  
Takayoshi Tanji ◽  
Keiji Yada
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Field Emission ◽  
Thermal Field ◽  
Thermionic Emission ◽  
Electron Gun ◽  
Field Evaporation ◽  
Good Reproducibility ◽  
High Brightness ◽  
Evaporation Technique

Thermal field emission (T.F.E.) properties of single crystal LaB6 -tips has been investigated by observing emission patterns. Applying field evaporation technique we succeeded to get the clean pattern consisting of <310> spots with very good reproducibility. This investigation has led to conclusion;, the <310> spot is promising electron source of high brightness provided that the tip is operated at tip temperature∽ 1000-1050°C in vacuum of 10−9 Torr region.As a preliminary experiment of brightness-measurement, we mounted the <310> LaB6-tip in a commercial type TEM, JEM-100CX-FEG, attached with an electron gun system for T.F.E. of <100> W-tip, being operated at 10−9 Torr region without Schottky shield electrode. The LaB6-tip, however, can not be operated without the Schottky shield because thermionic emission (T.E.) from the LaB6-tip is considerably high even though the tip is operated at lower than ∽1000 °C. In the present experiment, therefore, we manufactured a Schottky shield electrode as shown in Fig.l and performed the measurement of brightness by setting the Schottky shield electrode, applied the same voltage as the tip since the electron gun system has no extra feed-throughs for bias-voltage.

Optical characteristics of the hitachi HF-2000 cold field-emission TEM

1993 ◽  
Vol 51 ◽  
pp. 1076-1077
Author(s):  
L. F. Allard ◽  
E. Völkl ◽  
T. A. Nolan
Keyword(s):  
Field Emission ◽  
Recent Literature ◽  
Electron Gun ◽  
High Brightness ◽  
Condenser Lens ◽  
Illumination System ◽  
High Resolution Images ◽  
Imaging Mode ◽  
Better Than ◽  
Illuminating System

The illumination system of the cold field emission (CFE) Hitachi HF-2000 TEM operates with a single condenser lens in normal imaging mode, and with a second condenser lens excited to give the ultra-fine 1 nm probe for microanalysis. The electron gun provides a guaranteed high brightness of better than 7×l08 A/cm2/sr, more than twice the guaranteed brightness of Schottky emission guns. There have been several articles in the recent literature (e.g. refs.) which claim that the geometry of this illumination system yields a total current which is so low that when the beam is spread at low magnifications (say 10 kX), the operator must “keep his eyes glued to the binoculars” in order to see the image. It is also claimed that this illuminating system produces an isoplanatic patch (the area over which image character does not vary significantly) at high magnification which is so small that the instrument is ineffective for recording high resolution images.

Interference Experiments with a Field Emission Source

1970 ◽  
Vol 28 ◽  
pp. 534-535
Author(s):  
A. V. Crewe ◽  
J. Saxon
Keyword(s):  
Field Emission ◽  
Spherical Aberration ◽  
Electron Gun ◽  
Partial Coherence ◽  
Vacuum System ◽  
High Brightness ◽  
Small Spot ◽  
Tungsten Tip ◽  
Effective Source ◽  
Better Than

Field emission from a tungsten tip provides a source with very high brightness and high partial coherence. An electron gun of low spherical aberration is used to focus the electrons from the tip to a small spot about 100 Å in diameter. Since the voltages applied to the tip and gun are stable to better than 5 ppm, the temporal coherence is limited by the energy spread of the source, about 200 mv.Using the focused spot a few centimeters below the gun as an effective source, a metalized quartz fiber about 2 μ in diameter is positioned a few centimeters below the source, as shown in Fig. 1. Two cylindrica11y symmetric magnetic lenses are used to magnify the resulting Fresnel diffraction pattern. The image is produced on a fluorescent coating deposited on the vacuum side of a fiber optic window. The image is recorded directly on film placed against the window outside the vacuum system.

Dual Stage SEM with thermal field-emission gun

1989 ◽  
Vol 47 ◽  
pp. 94-95
Author(s):  
S. Yamazaki ◽  
T. Sato ◽  
S. Aota ◽  
R. Buchanan
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Thermal Field ◽  
Objective Lens ◽  
Wide Field ◽  
Operating Voltage ◽  
High Brightness ◽  
Voltage Range ◽  
Optical Configuration ◽  
Working Distance

Resolution improvement is an on-going goal in scanning electron microscope development. High resolution is required at both high and low accelerating voltages in a wide field of applications, including, but not exclusive to, semiconductors and new materials development. Two approaches which result in improved resolution through-out the operating voltage range of the SEM are 1) the adoption of low aberration objective lenses, and 2) the use of high brightness electron sources.The DS-130F SEM which is described here uses a high brightness thermal field emission gun (TFEG) in conjunction with a modified DS-130 column. The electron optical configuration is quite unique, as it includes two independent stages. The top stage places the sample within a high field strength low aberration objective lens, resulting in ultra high resolution on samples up to 18 x 8 mm. The bottom stage accommodates 6” samples and uses a second dedicated conical objective lens allowing a short working distance to be maintained on tilted samples.

Development of 350-KV holography electron microscope equipped with magnetic type field-emission electron gun

1989 ◽  
Vol 47 ◽  
pp. 104-105
Author(s):  
J. Endo ◽  
T. Kawasaki ◽  
T. Masuda ◽  
A. Tonomura
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
High Sensitivity ◽  
Beam Current ◽  
Electron Gun ◽  
Electron Holography ◽  
Electron Microscopic ◽  
Magnetic Lens ◽  
High Brightness ◽  
Emission Electron

A field-emission electron gun is one of the most epoch-making technologies in an electron microscopic world. In a transmission electron microscope, a high brightness of this beam has been effectively employed for electron-holographic measurements, though the value is not still high enough. Development of a higher brightness beam will promise to open up unattained application possibilities of electron holography such as high resolution and high sensitivity interferometry.We developed the field emission electron microscope for electron holographic applications. Special attentions were paid for high brightness, large beam current and easy operation. Figure 1 is a schematic diagram of the electron gun. In order not to deteriorate the original high-brightness feature of the beam by the aberrations in the gun and the condenser lenses, a magnetic lens was installed between the tip and the extraction anode so that the total aberration effect might be minimized. Field emitted electron beam is converged by the magnetic and the electrostatic lenses, and accelerated in a ten-stage accelerator which is made of porcelain.

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