• Transactions on Electrical and Electronic Materials
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• v.10 no.6
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• pp.193-195
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• 2009

This paper aims to develop a low gate source voltage ($V_{gs}$) N-LDMOS element that is fully operational at a CMOS Logic Gate voltage (3.3 or 5 V) realized using the 0.35 μm BCDMOS process. The basic structure of the N-LDMOS element presented here has a Low $V_{gs}$ LDMOS structure to which the thickness of a logic gate oxide is applied. Additional modification has been carried out in order to obtain features of an improved breakdown voltage and a specific on resistance ($R_{sp}$). A N-LDMOS element can be developed with improved features of breakdown voltage and specific on resistance, which is an important criterion for power elements by means of using a proper structure and appropriate process modification. In this paper, the structure has been made to withstand the excessive electrical field on the drain side by applying the double gate oxide structure to the channel area, to improve the specific on resistance in addition to providing a sufficient breakdown voltage margin. It is shown that the resulting modified N-LDMOS structure with the feature of the specific on resistance is improved by 31%, and so it is expected that optimized power efficiencies and the size-effectiveness can be obtained.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.2
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• pp.61-66
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• 2014

Exhaust heat recovery ventilation systems conserve energy through enthalpy recovery between air intake and exhaust, and they are being increasingly used. An exhaust heat recovery ventilation system can be installed in the ceiling of a balcony or emergency evacuation space. However, in the case of fire, the emergency evacuation space has to by law remain as empty space, and therefore, a ventilation system can't be installed in an emergency evacuation space. Therefore, the need for a proper installation space for a ventilation system is emphasized. In this study, to install a heat recovery ventilation system in a lightweight wall, a heat exchanger was assembled of thickness below 140 mm. The efficiency of heat recovery was analyzed through performance experiment, in the case of the cooling and heating mode. The heat recovery efficiency increases when the surface area is increased, by using closer channel spacing in the heat exchanger, or by increasing the size of the heat exchanger.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.2
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• pp.51-57
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• 2013

The current expanding mobile markets incessantly demands small form factor, low power consumption and high aggregate throughput for silicon-level integration such as memory to logic system. One of emerging solution for meeting this high market demand is 3D through silicon stacking (TSS) technology. Main challenges to bring 3D TSS technology to the volume production level are establishing a cost effective supply chain and building a reliable manufacturing processes. In addition, this technology inherently help increase number of IOs and shorten interconnect length. With those benefits, however, potential signal and power integrity risks are also elevated; increase in PDN inductance, channel loss on substrate, crosstalk and parasitic capacitance. This paper will report recent progress of wide IO memory to high count TSV logic device assembly development work. 28 nm node TSV test vehicles were fabricated by the foundry and assembled. Successful integration of memory wide IO chip with less than a millimeter package thickness form factor was achieved. For this successful integration, we discussed potential signal and power integrity challenges. This report demonstrated functional wide IO memory to 28 nm logic device assembly using 3D package architecture with such a thin form factor.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.80-84
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• 2014

The discharge characteristics of Surface Dielectric Barrier Discharge (SDBD) reactor are investigated to find optimal driving condition with adjusting various parameter. When the high voltage with sine wave form is applied to SDBD source, successive pulsed current waveforms are observed owing to multiple ignitions through the long discharge channel and wall charge accumulation on the dielectric surface. The discharge voltage, total charge between dielectrics, mean energy and power are calculated from measured current and voltage according to electrode gap and dielectric thickness. Discharge mode transition from filamentary to diffusive glow is observed for narrow gap and high applied voltage case. However, when the diffusive discharge is occurred with high applied voltage, the actual firing voltage is always lower than that with low driving voltage. The $Si_3N_4$, $MgF_2$, $Al_2O_3$ and $TiO_2$ are considered for dielectric protection and high secondary electron emission coefficient. SDBD with $MgF_2$ shows the lowest breakdown voltage. $MgF_2$ thin film is proposed as a protection layer for low voltage atmospheric dielectric barrier discharge devices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.1023-1026
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• 2010

In this paper, rheological property of polymer blends in a confined geometry was investigated. The shear viscosity was measured in a capillary rheometer incorporated with a specially designed piston and three slit dies having 0.1, 0.2 and 0.5 mm in thickness. It was observed that the viscosity of polymer blends does not depend on the die size when the phase of polymer blends is a sea-island structure. However, when the phase of polymer blends is a co-continuous structure, the viscosity of the blends was dependent on the die size. By additional investigations, this result is attributed to the slip phenomenon between polymer phases in the blends.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.751-754
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• 2000

When charge-trap SONOS cells are used flash memory, the tunneling program/erase condition to minimize the generation of interface traps was investigated. SONOSFET NVSM cells were fabricated using 0.35$\mu\textrm{m}$ standard memory cell embedded logic process including the ONO cell process. based on retrograde twin-well, single-poly, single metal CMOS process. The thickness of ONO triple-dielectric for memory cell is tunnel oxide of 24${\AA}$, nitride of 74 ${\AA}$, blocking oxide of 25 ${\AA}$, respectively. The program mode(Vg: 7,8,9 V, Vs/Vd: -3 V, Vb: floating) and the erase mode(Vg: -4,-5,-6 V, Vs/Vd: floating, Vb: 3V) by modified Fowler-Nordheim(MFN) tunneling were used. The proposed programming condition for the flash memory of SONOSFET NVSM cells showed less degradation($\Delta$Vth, S, Gm) characteristics than channel MFN tunneling operation. Also the program inhibit conditions of unselected cell for separated source lines NOR-tyupe flash memory application were investigated. we demonstrated that the program disturb phenomenon did not occur at source/drain voltage of 1 V∼4 V and gate voltage of 0 V∼4.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.171-172
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• 2007

We fabricated the metal-ferroelectric-insulator-semiconductor filed-effect transistors (MFIS-FETs) using the $(Bi,La)_4Ti_3O_{12}\;and\;LaZrO_x$ thin films. The $LaZrO_x$ thin film had a equivalent oxide thickness (EOT) value of 8.7 nm. From the capacitance-voltage (C-V) measurements for an Au/$(Bi,La)_4Ti_3O_{12}/LaZrO_x$/Si MFIS capacitor, a hysteric shift with a clockwise direction was observed and the memory window width was about 1.4 V for the bias voltage sweeping of ${\pm}9V$. From drain current-gate voltage $(I_D-V_G)$ characteristics of the fabricated Fe-FETs, the obtained threshold voltage shift (memory window) was about 1 V due to ferroelectric nature of BLT film. The drain current-drain voltage $(I_D-V_D)$ characteristics of the fabricated Fe-FETs showed typical n-channel FETs current-voltage characteristics.

• Nuclear Engineering and Technology
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• v.39 no.4
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• pp.349-358
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• 2007

A single-beam gamma densitometer is utilized to measure the average void fraction in a small diameter stainless steel pipe under critical flow conditions. A typical design of a single-beam gamma densitometer is composed of a sealed gammaray source, a collimator, a scintillation detector, and a data acquisition system that includes an amplifier and a single channel analyzer. It is operated in the count mode and can be calibrated with a test pipe and various types of phantoms made of polyethylene. A good average void fraction is obtained for a small diameter pipe with various flow regimes of the core, annular, stratified, and bubbly flows. Several factors influencing the performance of the gamma densitometer are examined, including the distance between the source and the detector, the measuring time, and the ambient temperature. The void fraction is measured during an adiabatic downward two-phase critical flow in a vertical pipe. The test pipe has an inner diameter of 10.9 mm and a thickness of 3.2 mm. The average void fraction was reasonably measured for a two-phase critical flow in the presence of nitrogen gas.

• Korean Circulation Journal
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• v.48 no.12
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• pp.1135-1144
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• 2018

Background and Objectives: Mitochondria play a key role in the pathophysiology of heart failure and mitochondrial permeability transition pore (MPTP) play a critical role in cell death and a critical target for cardioprotection. The aim of this study was to evaluate the protective effects of cyclosporine A (CsA), one of MPTP blockers, and morphological changes of mitochondria and MPTP related proteins in monocrotaline (MCT) induced pulmonary arterial hypertension (PAH). Methods: Eight weeks old Sprague-Dawley rats were randomized to control, MCT (60 mg/kg) and MCT plus CsA (10 mg/kg/day) treatment groups. Four weeks later, right ventricular hypertrophy (RVH) and morphological changes of right ventricle (RV) were done. Western blot and reverse transcription polymerase chain reaction (RT-PCR) for MPTP related protein were performed. Results: In electron microscopy, CsA treatment prevented MCT-induced mitochondrial disruption of RV. RVH was significantly increased in MCT group compared to that of the controls but RVH was more increased with CsA treatment. Thickened medial wall thickness of pulmonary arteriole in PAH was not changed after CsA treatment. In western blot, caspase-3 was significantly increased in MCT group, and was attenuated in CsA treatment. There were no significant differences in voltage-dependent anion channel, adenine nucleotide translocator 1 and cyclophilin D expression in western blot and RT-PCR between the 3 groups. Conclusions: CsA reduces MCT induced RV mitochondrial damage. Although, MPTP blocking does not reverse pulmonary pathology, it may reduce RV dysfunction in PAH. The results suggest that it could serve as an adjunctive therapy to PAH treatment.

• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.100-105
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• 2021

This paper proposes the polydimethylsiloxane (PDMS) blade coating method for fabrication of paper-based analytical device (PAD) that is able to monitor the disease diagnosis and progress without special analytical equipment. The mold that has PAD design is easily modified by using laser cutting technique. And the fabricated mold is used for hydrophobic barrier formation by blade coating. We have optimized the stable formation of PDMS hydrophobic barrier as blade coating condition, which is established by analyzing the structure of the PDMS hydrophobic barrier and change of hydrophilic channel size as thickness of the ink and contact time with the chromatography paper. Based on optimal condition, we demonstrate that PAD as biosensor can apply to detect protein, glucose, and metal ion without special analysis equipment.