• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.45-45
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• 2009

This paper describes the formation of porous 3C-SiC by anodization. 3C-SiC thin films were deposited on p-type Si(100) substrates by APCVD using HMDS (Hexamethyildisilane: $Si_2(CH_3)_6$). UV-LED(380 nm) was used as a light source. The surface morphology was observed by SEM and the pore size was increased with increase of current density. Pore diameter of 70 ~ 90 nm was achieved at 7.1 $mA/cm^2$ current density and 90 sec anodization time. FT-IR was conducted for chemical bonding of thin film and porous 3C-SiC. The Si-H bonding was observed in porous 3C-SiC around wavenumber 2100 $cm^{-1}$. PL shows the band gap enegry of thin film (2.5 eV) and porous 3C-SiC (2.7 eV).

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.119-122
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• 2005

A algorithm for control and performance of a pulse-density-modulated (PDM) series-resonant voltage source inverter developed for corona-dischange precesses is presented. The PDM inverter produces either a square-wave ac-voltage state or a zero-voltage state at its ac terminals to control the average output voltage under constant dc voltage and operating frequency. Moreover it can achieve zero-current-switching (ZCS) and zero-voltage-switching (ZVS) in all the operating condition for a reduction of switching lost. Even though the corona discharge load with a strong nonlinear characteristics, new high frequency resonant inverter is shown the wide range power control from 5% to 100%.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.7
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• pp.49-57
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• 2008

This paper presents a voltage source type half-bridge series resonant high frequency (HF) inverter for induction heated fixing roller in copy machines. This high-frequency inverter works under zero current soft switching (ZCS) commutation and has wide power regulation range due to employing a pulse density modulation (PDM) scheme. Transient and steady state operating modes of the inverter are presented in this paper together with its PDM-based power regulation system. Experimental operating performances of the developed HF-ZCS inverter as well as power losses and actual efficiency are discussed and compared with computer simulation results.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.2
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• pp.63-67
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• 1992

Shallow $p^{+}-n,n^{+}-p$ diodes have been fabricated using rapid thermal diffusion by solid diffusion source and rapid thermal alloying with pure Aluminum. Diode area and junction depth are designed about 2.83$[\times}10^{-3}cm^{2}$ and 250nm, respectively. Electrical characteristics of $p^{+}-n$ diode show that the ideality factor is 1.04 and reverse current density is 29.3nA/$cm^{2}$, respectively. On the other hand, those of $n^{+}-p$ diode show that the ideality factor is 1.05 and reverse current density is 85.2pA/$cm^{2}$. The reverse currents are measured at 5V reverse bias after rapid thermal alloying for all the measurement.

• Advances in nano research
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• v.3 no.1
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• pp.49-54
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• 2015

The structure represents symmetrical metal electrode (gate 1) - front $SiO_2$ layer - n-Si nanowire FET - buried $SiO_2$ layer - metal electrode (gate 2). At the symmetrical gate voltages high conductive regions near the gate 1 - front $SiO_2$ and gate 2 - buried $SiO_2$ interfaces correspondingly, and low conductive region in the central region of the NW are formed. Possibilities of applications of nanosize FETs at the deep inversion and depletion as a distributed capacitance are demonstrated. Capacity density is an order to ${\sim}{\mu}F/cm^2$. The charge density, it distribution and capacity value in the nanowire can be controlled by a small changes in the gate voltages. at the non-symmetrical gate voltages high conductive regions will move to corresponding interfaces and low conductive region will modulate non-symmetrically. In this case source-drain current of the FET will redistributed and change current way. This gives opportunity to investigate surface and bulk transport processes in the nanosize inversion channel.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.162-163
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• 2000

We have observed the short-channel effect, narrow-channel effect and small-geometry effect in terms of a variation of the threshold voltage. For a short-channel effect the threshold voltage was largely determined by the DIBL effect which stimulates more carrier injection in the channel by reducing the potential barrier between the source and channel. The effect becomes more significant for a shorter-channel device. However, the potential, field and current density distributions in the channel along the transverse direction showed a better uniformity for shorter-channel devices under the same voltage conditions. The uniformity of the current density distribution near the drain on the potential minimum point becomes worse with increasing the drain voltage due to the enhanced DIBL effect. This means that considerations for channel-width effect should be given due to the variation of the channel distributions for short-channel devices. For CCDs which are always operated at a pinch-off state the channel uniformity thus becomes significant since they often use a device structure with a channel length of > 4 ${\mu}{\textrm}{m}$ and a very high drain (or diffusion) voltage. (omitted)

• Journal of the Korean Vacuum Society
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• v.1 no.1
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• pp.212-222
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• 1992

To use polycrystalline Si Thin Film Transistor (poly-Si TFT) in high density SRAM instead of High Load Resistor (HLR), TFT is needed to show good electrical characteristics such as large carrier mobility, low leakage current, high driver current and low subthreshold swing. To satisfy these electrical characteristics, the trap state density must be reduced in the channel poly. Technological issues pertinent to the channel poly fabrication process are investigated and discussed. They are solid phase growth (SPG), Si-ion implantation, laser annealing and hydrogenation. The electrical properties of several CVD oxides used as the gate oxide of TFT are compared. The dependence of the electrical characteristics of TFT on source-drain ion-implantation dose, drain offset length and dopant lateral diffusion are also described.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.12
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• pp.558-560
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• 2005

The carbon film was deposited by the electrolysis of methanol solution. Carbon films have been grown on silicon substrates using the method of chemical process. From investigations of the Raman spectroscopy and the FTIR spectroscopy, the carbon film deposited by the electrolysis was identified the hydrogenated carbon film with the porous structure. The carbon film deposited by elctrolysis of methanol was identified as the hydrogenated carbon film with porous structure. Deposition parameters for the growth of the carbon films were current density, methanol liquid temperature. We electrical resistance and surface morphology of carbon films formed various conditions specified by deposition parameters. It was clarified that the high electrical resistance carbon films with smooth surface morphology are grown when a distance between the electrodes is relatively wider. We found that the electrical resistance in the films independent of both current density and methanol liquid temperature. The temperature dependence of the electrical resistance in the low resistance carbon films is different from one obtained in graphite..

• Transactions of the Korean hydrogen and new energy society
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• v.14 no.3
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• pp.195-206
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• 2003

Polymer electrolyte membrane fuel cells(PEMFC) are very interesting power source due to high power density, simple construction and operation at low temperature. But they have problems such as high cost, improvement of performance and effect of temperature. This problems can be approached using mathematical models which are useful tools for analysis and optimization of fuel cell performance and for heat and water management, in this paper, transient model consists of various energy terms associated with fuel cell operation using the mass and energy balance equation. And water transfer in the membrane is composed of back diffusion and electro-osmotic drag. The temperature calculated by transient model approximately agreed with the temperature measured by experiment in constant current condition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.5
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• pp.477-479
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• 2006

Carbon films was grown on Si substrates using the method of electrolysis for methanol liquid. Deposition parameters for the growth of the carbon films were current density for the electrolysis, methanol liquid temperature and electrode spacing between anode and cathode. We examined electrical resistance and the surface morphology of carbon films formed under various conditions specified by deposition parameters. It was clarified that the high electrical resistance carbon films with smooth surface morphology are grown when a distance between the electrodes was relatively wider. We found that the electrical resistance in the films was independent of both current density and methanol liquid temperature for electrolysis. The temperature dependence of the electrical resistance in the low resistance carbon films was different from one obtained in graphite.