• Vacuum Magazine
• /
• v.2 no.2
• /
• pp.24-28
• /
• 2015

The brightness of an electron source, along with the aberrations of an objective lens, determines the image resolution and beam current on samples, which are two important parameters for evaluating the performance of an electron microscope. Here we introduce thermal electron source, Schottky emitter and cold field electron emitter. Thermal electron source is the cheapest and stable electron source but it has the lowest brightness. Schottky emitter is 10000 times brighter than tungsten thermal electron source, but requires ultrahigh vacuum operating condition. Cold field electron emitter is 10 times brighter than Schottky emitters, but it is rather unstable and its operation requires most stringent vacuum condition, hindering its widespread use.

• Journal of Korean Vacuum Science & Technology
• /
• v.4 no.4
• /
• pp.93-96
• /
• 2000

Microchannel plates (MCPs) have been developed by introducing new materials and process technologies. Main body was made of alumina by programmable punching, laminating, and firing. The channel walls of pore arrays of an MCP were deposited with thin films by electroless copper plating and sol-gel process. Our MCP has advantages such as easy fabrication, durability, high temperature endurance, and applicability to the large size comparing with the conventional MCPs. Experiments on the brightness of an MCP incorporated FED revealed that the FED with a MCP is three to four times brighter than a conventional FED. Moreover, the focusing in a FED is improved. Incorporating an MCP into a FED is one of promising methods to enhance the characteristics of the FED. In addition, amplification yield of the MCP is measured for varying the aspect ratio and the input current.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.1028-1031
• /
• 2002

Ga-based semiconductor nanowires (GaN, GaP) were synthesized by the reaction of Ga metal and GaN/GaP powder with a $NH_3/Ar$ gas using thermal chemical vapor deposition. The field emission and emission stability under oxygen and argon environments were investigated. Field emission energy distributions of electrons from these nanowires revealed that field emission mechanism of the semiconductor nanowires were different from carbon nanotubes.

• Journal of Information Display
• /
• v.12 no.2
• /
• pp.69-75
• /
• 2011

A new electron source and an electron collection source were found for the closure of the internal electron circuit inside fluorescent lamp (FL) tubes. The sources are formed in front of the polarized electric-insulator particles on the metal electrodes at both ends of the FL tube. The appearance and disappearance of both sources are controlled by the electric voltages applied to the metal electrodes. The electrons and $Ar^+$ for the sources are generated by the ionization of the Ar atoms, and they return to the Ar atoms at the electron collection source. Thus, the Ar atoms are preserved in the FL tubes, ensuring a long operation life for such tubes.

• Journal of Information Display
• /
• v.2 no.4
• /
• pp.23-28
• /
• 2001

Field emission characteristics of carbon nanotubes(CNTs) on four kinds of metallic substrates have been investigated under the irradiation of a laser. The field emission measurement reveals that after laser irradiation the current was increased and new humps at the field emission current was found. The current enhancement was thought to have occurred due to the fact that the electrical contact between CNTs and metals was improved due to the irradiation of the laser.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.1
• /
• pp.17-21
• /
• 2010

Currently miniaturized electron-optical columns find their way into electron beam lithography systems. For better lithography process, it is required to make smaller spot size and longer working distance. But, the micro-columns of the multi-beam lithography system suffer from chromatic and spherical aberration, even when the electron beam is exactly on the symmetric axis of the micro-column. The off-axis error of the electron emitting source is expected to become worse with increasing off-axis distance of the focusing spot. Especially the electron beams far from the system optical axis have a non-negligible asymmetric intensity distribution in the micro-column. In this paper, the effect of the off-axis e-beam source is analyzed. To analyze this effect is to introduce a micro-column model of which the e-beam emitting source is aligned with the center of the electron beam by shifting them perpendicular to the system optical axis. The presented solution can be used to analysis the performance of the multi-electron-beam system. The performance parameters, such as the working distances and the focusing position are obtained by the computational simulations as a function of the off-axis distance of the emitting source.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.12a
• /
• pp.71-74
• /
• 2006

Discharge of the flat lamp lighting source research arc requested very much. For improving brightness, life time, efficiency of flat lamp, plasma diagnosis of the flat lamp lighting source to understand property of lighting source is very important. distance of discharge electrode is 5.5mm and width is 16.5mm, we measured electron temperature and electron density measured with single langmuir probe in flat lamp. we tested the discharge from 100 Torr to 300 Torr pressure. the Pulse is rectangular pulse with frequency 20kHz and Duty ratio 20%. Resultly, electron temperature decreases and electron density increase as increase the gas pressure and electron temperature decreases and electron density increase as increase the voltage.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2190-2192
• /
• 2005

Discharge of the flat lamp lighting source research are requested very much. For improving brightness, life time, efficiency of flat lamp, plasma diagnosis of the flat lamp lighting source to understand property of lighting source is very important. distance of discharge electrode is 5.5mm and width is 16.5mm, we measured electron temperature and electron density measured with single langmuir probe in flat lamp. we tested the discharge from 100 Torr to 300 Torr pressure. the Pulse is rectangular pulse with frequency 20kHz and Duty ratio 20%. Resultly, electron temperature decreases and electron density increase as increase the gas pressure and electron temperature decreases and electron density increase as increase the voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.05a
• /
• pp.86-90
• /
• 2006

Discharge of the flat lamp lighting source research are requested very much. For improving brightness, life time, efficiency of flat lamp, plasma diagnosis of the f1at lamp lighting source to understand property of lighting source is very important. Distance of discharge electrode is 5.5mm and width is 16.5mm, we have measured electron temperature and electron density measured with single Langmuir probe in flat lamp. We have tested the discharge from 100 Torr to 300 Torr pressure. The pulse is rectangular pulse with frequency 20kHz and duty ratio 20%. In result, electron temperature decreases and electron density increase as increase the gas pressure and electron temperature decreases and electron density increase as increase the voltage.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.1
• /
• pp.23-28
• /
• 2008

Due to the modem MEMS technologies, the electron lenses that are used in the microcolumn can have much smaller optical aberrations compared with conventional electron lenses for the bulky electron columns. Since the electron lens system have great effect on the performance of the microcolumn, it is important to study the dependence of image quality on the configuration of the electronic imaging system, among which the source-lens part is most sensitive. In this work, we investigated the electron beam characteristics according to the shapes of extractor and limiting aperture that are elements of the source-lens part. By analyzing the data obtained, we proposed the optimum configuration of the electron lens system.