• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.3
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• pp.87-95
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• 1992

The electrical characteristics of Al/TaS12TOS15T/SiOS12T/Si metal insulator-semiconductor (MIS) capacitors were studied. Tantalum pentoxide thin films on SiOS12T/p-Si substrate have been prepared by thermal oxidation at 450-$600^{\circ}C$ of sputter deposited tantalum films. Composition and structures of the tantalum oxide films were examined by AES and XRD. From the C-V analysis, dielectric constant of TaS12TOS15T which were oxidized at 55$0^{\circ}C$ for 1h in OS12T were 18-23, the value depending on the oxidation and annealing temperature. The leakage current density was found to be about 10S0-10T-10S0-9T A/cmS02T at an applied electric field of 1 MV/cm. The dielectric breakdown strength of the tantalum oxide films annealed at 100$0^{\circ}C$ were in the range from 2.5MV/cm to 2.8 MV/cm.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.386-391
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• 2004

To find out the reason of accident by being stained of insulators, this paper researched and analyzed the result of electrical characteristic test and field test of EHV insulator through artificial contaminated method. The best way to evaluate contaminated level of insulator surface is getting a contamination data by regional groups continually. But it is needed a lot of time and manpower. To overcome those difficulties, this research introduced ESDD(equivalent salt deposit density) measurement method which is adapted to the international codes of IEC and compared the relation between experimental test results which contaminated insulators by going through stain procedure and electrical measurement results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.509-512
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• 2001

Aluminum nitride(AIN) thin films were deposited on silicon substrates using RF magnetron sputtering at various deposition conditions and investigated the characteristics. It was used XRD, AES, SEM, and HP-4145B semiconductor parameter analyzer to analysis deposited AIN thin films. The deposition conditions for the good c-axis orientation were 100 W of RF power, 200$^{\circ}C$ of substrate temperature and 15 mTorr of working Pressure. The leakage current density was less then 1.3${\times}$10$\^$-7/ A/$\textrm{cm}^2$. And it was also investigated the etching properties of deposited AIN thin films for application.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.156-160
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• 2009

This paper presents the interleaved active-clamping ZVS(Zero Voltage Switching) forward converter, which is mainly composed of two active-clamping forward converters. Only two switches are required, and each one is the auxiliary switch for the other. The circuit complexity and cost are thus reduced. The leakage inductance of the transformer or an additional resonant inductance is employed to achieve ZVS during the dead times. The duty cycles are not limited to be equal and within 50%. The complementary switching and the resulted interleaved output inductor currents diminish the current ripple in output capacitors. Accordingly, the smaller output chokes and capacitors lower the converter volume and increase the power density. Detailed analysis and design of this new interleaved active-clamping forward converter are described.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.474-475
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• 2007

The $Sr_{0.8}Bi_{2.2}Ta_2O_9$(SBT) thin films are deposited on Pt-coated electrode(Pt/$TiO_2/SiO_2$/Si) using RF magnetron sputtering method. The aging properties of SBT capacitor with top electrodes represents a favorable properties in Pt electrode. The dielectric constant and leakage current density with Pt electrode is 340 and $6.81{\times}10^{-10}\;A/cm^2$ respectively. The maximum remanent polarization and the coercive electric field with Pt electrode are $12.40{\mu}C/cm^2$ and 30kV/cm respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.278-281
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• 1999

PLZT thin films on Pt/Ti/SiO$_2$/Si substrate were fabricated with different Thickness by pulsed laser deposition. 14/50/50 PLZT thin film showed a maximum dielectric constant value of $\varepsilon$$_{t}$=985 at 5000$\AA$, and $\varepsilon$$_{t}$=668 at 2000A. P-EI hysteresis loop of 14/50/50 PLZT thin film was slim ferroelectric. Leakage current density of 14/50/70 PLZT thin film was 10$^{-8}$ A/$\textrm{cm}^2$ at 2000$\AA$.EX>.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.240-243
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• 1999

(Sr$\sub$0.85/Ca$\sub$0.15/)TiO$_3$thin films were deposited on Pt-coated TiO$_2$/SiO$_2$/Si wafer by the rf sputtering method. Experiments were conducted to investigate the electrical properties of SCT thin films with various top electrode. C-F and C-V measurements show that SCT thin films annnealed at 600$^{\circ}C$ have a larger capacitance than SCT thin films deposited at 400$^{\circ}C$ , and there is nearly no difference between top electrodes. I-V measurement show that Pt top electrode have a good leakage current density of < 10nA/$\textrm{cm}^2$,. making them suitable for DRAM application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.194-195
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• 2006

Aluminum oxide films directly grown on n-type 6H-SiC(0001) substrates were fabricated by RF magnetron sputtering system. Metal-insulator-semiconductor(MIS) C-V properties with aluminum oxide thin films showed hysteresis and f1at band voltage shift. The dielectric constant of the film calculated from the capacitance at the accumulation region was about 5. Typical gate leakage current density of film at room temperature was the order of $10^{-9}\;A/cm^2$ at the range of within 2MV/cm. The breakdown did not occur at the film within the measurement range.

• Journal of Korean Vacuum Science & Technology
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• v.2 no.2
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• pp.92-96
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• 1998

Ferroelectric Bi-layered oxides SrBi2Ta2O9 (SBT) thin films have been deposited on Pt/Ti/SiO2/Si substrates using multi-target sputtering. Structure, composition, and electrical properties have been investigated on films. The SBT films were deposited with the various bismuth sputtering powers. The SBT films deposited with the bismuth sputtering power of 20 W have the most dense microstructure and the remanent polarization (Pr) of 9.2 ${\mu}$C/cm and the coercive field (Ec) of 43.8 kV/cm at an applied voltage of 5V. The SBT films deposited with the bismuth sputtering power of 20W showed a fatigue-free characteristics up to 1.0${\times}$1010 cycles under 5V bipolar pulse and a leakage current density of 2.0${\times}$10-8 A/$\textrm{cm}^2$ at 200 kV/cm.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.295-296
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• 2019

본 논문은 넓은 출력전압 범위와 High Power Density를 위한 절연형 HMF PFC(Isolated Harmonic Modulation PFC)를 제안한다. 제안된 PFC는 변압기 leakage inductance를 회로에 적용시켜 switching device의 voltage stress를 효과적으로 줄일 수 있는 voltage-fed형태의 ful-bridge구조를 기반으로 한다. 출력 측 CV(Constant Voltage) control을 통하여 출력 혹은 link 전압을 load 변동에 상관없이 일정 유지시켜준다. 또한 CC(Constant Current) control 방식을 사용하여 출력 측 battery 특성 조건이 변동되어도 일정하게 충전시켜 줄 수 있도록 한다. HMF 제어방식을 적용한 3.3kW Prototype을 통해 이를 입증한다.