• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.139-140
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• 2000

The origin of the display current in the surface conduction electron emitter displays has been verified in the calculation of the electron trajectory. Some electrons move directly toward the display surface as an anode current which is generated due to the inertial force of electron motion along the curved electric field lines with a small curvature near the fissure area..

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.67-70
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• 2000

In this paper, all SCR recombination currents including setback and graded layer's recombination currents are analytically introduced for the first time. Different emitter-base structures are tested to prove the validity of the model. In 1995, the analytical equations of electric field, electrostatic potential, and junction capacitance for abrupt and linearly graded heterojunctions with or without a setback layer was derived. But setback layer and linearly graded layer's recombination current was considered numerically. In this paper, recombination current model included setback layer and graded layer is proposed. New recombination current model also includes abrupt heterojunction's recombination current model. In this paper, new recombination current model analytically explains effects of setback layer and graded layer.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.21-24
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• 2008

Properties of carbon nano fiber (CNF) as field emitters were described. Carbon nano fiber (CNF) of herringbone was prepared by thermal chemical vapor deposition(CVD). Field emitters mixed with organic binders, conductive materials and were prepared by screen-printing process. In order to increase field emissions, the surface treatment of rubbing & peel-off was applied to the printed CNF emitters on cathode electrode. The measurements of field emission properties were carried out by using a diode structure inline vacuum chamber. CNF of herringbone type showed good emission properties that a turn on field was as low as 2.1 $V/{\mu}m$ and current density was as large as 0.15 $mA/cm^2$ of 4.2 $V/{\mu}m$ with electric field. Through the results. we propose that CNFs are suitable for application of electron emitters in Field Emission Devices.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.392-392
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• 2011

Carbon nanotubes (CNT) emitter has widely become an attractive mechanism that draws growing interests for cold cathode field emission.$^{1,2}$ CNT yarns have demonstrated its potential as excellent field emitters.$^3$ Extensive simulations were carried out in designing a CNT yarn-based cathode assembly. The focal spot size dependence on the anode surface of the geometric parameters such as axial distance of the electrostatic focus lens from the cathode and the applied bias voltages at the cathode, grid mesh and electrostatic focus lens were studied. The detailed computer simulations using Opera 3D electromagnetic software$^4$ had revealed that a remarkable size of focal spot under a focusing lens triode type set-up design was achieved. The result of this optimization simulation would then be applied for the construction of the CNT yarn based micro-focus x-ray tube with its field emission characteristics evaluated.

• Journal of IKEEE
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• v.25 no.2
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• pp.350-355
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• 2021

IGBT is a power semiconductor device that contains both MOSFET and BJT structures, and it has fast switching speed of MOSFET, high breakdown voltage and high current of BJT characteristics. IGBT is a device that targets the requirements of an ideal power semiconductor device with high breakdown voltage, low V_CE-SAT, fast switching speed and high reliability. In this paper, we analyzed Gate oxide thickness, Trench Gate Width, and P+Emitter width, which are the top process parameters of 1,200V Trench Gate Field Stop IGBT, and suggested the optimized top process parameters. Using the Synopsys T-CAD Simulator, we designed IGBT devices with electrical characteristics that has breakdown voltage of 1,470 V, V_CE-SAT 2.17 V, Eon 0.361 mJ and Eoff 1.152 mJ.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.519-523
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• 2000

Using plasma-enhanced chemical vapor deposition (PECVD), carbon thin film as electron field emitter were fabricated. These carbon thin film were deposited on Si(100) substrate at several RF power. These film were estimated by raman spectroscopy, scanning electron microscopy, and field emission. The field electron emission property of these carbon thin film was estimated by a diode technique. As the result, we observed that the field emission properties of these films were promoted by higher RF power. These results are explained as change of surface morphology and structural properties of carbon thin film

• Journal of the Korean Vacuum Society
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• v.14 no.4
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• pp.252-257
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• 2005

A high-brightness electron beam source for a microfocus X-ray tube has been fabricated using a carbon-nanotube (CNT) field emitter. The electron source consists of cathode that includes a CNT field emitter, a beam-extracting grid, and an anode that accelerates that electron beam. The microfocus X-ray tube requires an electron beam with the diameter of less than 5 $\mu$m and beam current of higher than 30 $\mu$A at the position of the X-ray target. To satisfy the requirements, the geometries of the field emitter tips and the electrodes of the gun was optimized by calculating the electron trajectories and beam spatial profile with EGUN code. The CNT tips were fabricated with successive steps: a tungsten wire with the diameter of 200 $\mu$m was chemically etched and was subsequently coated with CNTs by chemical vapor deposition. The experiments of electron emission at the fabricated CNT tips were performed. The design characteristics and basic experimental results of the electron source are reported.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.3
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• pp.234-240
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• 2001

Using RF magnetron sputtering, amorphous carbon(a-C) thin films as electron filed emitter were fabricated. these a-C thin films were deposited on Si(001) substrate at several temperatures. The field electron emission property of these a-C thin films was estimated by a diode technique. As the result, we observed that the field emission properties of the films were changed singnificantly with the substrate temperature and structural features of a-C film. The field emission properties were promoted by higher substrate temperatures. Furthermore N-doped a-C film exhibits more field emission property than that of undoped a-C film. These results are explained as change of surface morphology and structural properties of a-C film.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.384-384
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• 2011

Carbon nanotubes (CNTs) have been studied as an ideal material for field emitters due to the high aspect ratio, excellent electrical property and good mechanical strength. There were many reports on CNT emitters fabricated on rigid substrates, but rare reports about CNT flexible field emitters. Recently, we considered that CNTs can be a good candidate for a flexible field emitter material because of their excellent Young's modulus and elasticity, which could not be achieved with metal tips or semiconducting nanowire tips. In this work, we demonstrated the CNT flexible field emitters fabricated by a simple method and studied the field emission properties of the CNT flexible field emitters under various bending conditions. The flexible field emitters showed stable and uniform emission characteristics. Especially, there is no remarkable change of the field emission properties at the CNT flexible field emitters according to the bending conditions. The CNT flexible field emitters also exhibited a good field emission performance like the low turn-on field and high emission current. Therefore, we suggest that the CNT flexible emitters can be used in many practical applications under different bending conditions.

• Journal of Information Display
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• v.9 no.4
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• pp.30-34
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• 2008

Field emitter arrays (FEAs) were developed using carbon nanotubes (CNTs) as electron emission sources. The CNTs were grown using a selective-positioning technique with a resist-protection layer. The light emission properties were studied through the electron emission of the CNTs on patterned islands, which were modulated with island diameter and spacing. The electron emission of CNT arrays with $5{\mu}m$ diameters and $10{\mu}m$ heights increased with increased spacing (from $10{\mu}m$ to $40{\mu}m$). The electron emission current of the $40-{\mu}m$-island-spacing sample showed a current density of 1.33 mA/$cm^2$ at E = 11 V/${\mu}m$, and a turn-on field of 7 V/${\mu}m$ at $1{\mu}A$ emission current. Uniform electron emission current and light emission were achieved with $40{\mu}m$ island spacing and $5{\mu}m$ island diameter.