• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.241.1-241.1
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• 2014

The large-area high-power radio-frequency (RF) driven ion sources based on the negative hydrogen (deuterium) ion beam extraction are the major components of neutral beam injection (NBI) systems in future large-scale fusion devices such as an ITER and DEMO. Positive hydrogen (deuterium) RF ion sources were the major components of the second NBI system on ASDEX-U tokamak. A test large-area high-power RF ion source (LAHP-RaFIS) has been developed for steady-state operation at the Korea Atomic Energy Research Institute (KAERI) to extract the positive ions, which can be used for the NBI heating and current drive systems in the present fusion devices, and to extract the negative ions for negative ion-based plasma heating and for future fusion devices such as a Fusion Neutron Source and Korea-DEMO. The test RF ion source consists of a driver region, including a helical antenna and a discharge chamber, and an expansion region. RF power can be transferred at up to 10 kW with a fixed frequency of 2 MHz through an optimized RF matching system. An actively water-cooled Faraday shield is located inside the driver region of the ion source for the stable and steady-state operations of RF discharge. The characteristics and uniformities of the plasma parameter in the RF ion source were measured at the lowest area of the expansion bucket using two RF-compensated electrostatic probes along the direction of the short- and long-dimensions of the expansion region. The plasma parameters in the expansion region were characterized by the variation of loaded RF power (voltage) and filling gas pressure.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.88-88
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• 2018

DLC(Diamond Like Carbon) 박막은 높은 열전도도, 큰 전기저항, 높은 강도 등의 다이아몬드와 유사한 특성을 가지고 있으면서 저온 저압에서도 합성이 가능하고, 합성 조건에 따라 물리 화학적 특성도 넓게 조절 할 수 있으며 상대적으로 넓은 면적에서 균일하고 평활한 박막의 합성이 가능하여 산업적 응용 면에서도 경쟁력을 갖추고 있다[1]. 이러한 DLC 박막을 합성함에 있어서 RF-PECVD(Radio Frequency Plasma Enhanced Chemical Vapor Deposition) 방법은 PECVD 방법 중 가장 보편적으로 사용되고 또 캐패시터 타입의 RF-PECVD 방법은 균일한 대면적 증착과 대량생산이 가능하다[1,2]. 본 연구에서는 우수한 특성을 갖는 DLC 박막의 증착 조건을 찾기 위해 캐패시터 타입의 RF-PECVD를 사용하여 공정 가스의 유량과 RF Power를 변화하여 박막을 증착하고, 증착된 박막의 특성을 연구하였다. DLC 박막은 ITO(Indium Tin Oxide) 유리 기판 위에 $100^{\circ}C$에서 5 min 동안 아세틸렌($C_2H_2$) 가스를 사용하여 가스 유량과 RF Power를 변화하여 증착하였다. 증착된 DLC 박막의 특성은 투과도, 평탄도, 두께를 측정하여 비교하였다. 가시광선 영역(380-780 nm)에서 투과도를 측정한 결과 ITO 유리 기판을 기준으로 한 DLC 박막의 투과도는 가시광선 영역 평균 94.8~98.8% 사이의 값으로 매우 높은 투과율을 나타내었다. 투과도는 가스 유량이 증가함에 따라 증가하는 경향을 나타내었고, RF Power의 변화에는 특정한 변화를 나타내지 않았다. 박막의 평탄도($R_a$, $R_{rms}$)와 두께는 AFM(Atomic Force Microscope)을 사용하여 측정하였다. 평탄도 $R_{rms}$는 0.8~3.3 nm, $R_a$는 0.6~2.5 nm 사이를 나타내었고 RF Power와 가스 유량의 변화에 따른 경향성을 나타내지는 않았다. 두께는 RF Power 25 W에서 55 W로 증가함에 따라 증가하는 경향을 나타내었으나 70W에서는 가스의 유량에 따라 상이한 결과를 나타내었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권6호
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• pp.287-290
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• 2006

A class-E CMOS RF(Radio frequency) power amplifier with a 1.8 Volt power supply is designed using $0.25{\mu}m$ standard CMOS technology. To drive the class-E power amplifier, a Class-F RF power amplifier is used and the reliability characteristics are studied with a class-E load network. After one year of operating the power amplifier with an RF choke, the PAE(Power Added Efficiency) decreases from 60% to 47% and the output power decreases 29%. However, when a finite DC-feed inductor is used with the load, the PAE decreases from 60% to 53% and the output power decreases only 19%. The simulated results demonstrate that the class-E power amplifier with a finite DC-feed inductor exhibits superior reliability characteristics.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.255-258
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• 1996

This paper describes a DC voltage controller for the DC power supply which is constructed using the full-bridged MOS-FET DC-to-RF power inverter and rectifier. The full-bridged MOS-FET DC-to-RF inverter consisting of four MOSFET arrays and an output power transformer has a control function which is able to control the RF output power when the widths of the pulse voltages which are fed to four MOS-FET arrays of the fall-bridged inverter are changed using the pulse width control circuit. The power conversion efficiency of the full-bridged MOS-FET DC-to-RF power inverter was approximately 85 % when the duty cycles of the pulse voltages were changed from 30 % to 50 %. The RF output voltage from the full-bridged MOS-FET DC-to-RF inverter is fed to the rectifier circuit through the output transformer. The rectifier circuit consists of GaAs schottky diodes and filters, each of which is made of a coil and capacitors. The power conversion efficiency of the rectifier circuit was over 80 % when the duty cycles of the pulse voltages were changed from 30 % to 50 %. The output voltage of the rectifier circuit was changed from 34.7V to 37.6 V when the duty cycles of the pulse voltages were changed from 30 % to 50 %.

• 한국전기전자재료학회논문지
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• 제35권5호
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• pp.488-493
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• 2022

Generally, diamond-like carbon films (a-C:H, DLC) have been shown to have a low coefficient of friction, a high hardness and a low wear rate. Pd-doped C thin film was fabricated using a dual magnetron sputtering with two targets of graphite and palladium. Graphite target RF power was fixed and palladium target RF power was varied. The structural, physical, and surface properties of the deposited thin film were investigated, and the correlation among these properties was examined. The doping ratio of Pd increased as the RF power increased, and the surface roughness of the thin film decreased somewhat as the RF power increased. In addition, the hardness value of the thin film increased, and the adhesive strength was improved. It was confirmed that the value of the contact angle indicating the surface energy increases as the RF power increases. It was concluded that the increase in RF power contributed to the improvement of the physical properties of Pd-doped C thin film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.125-125
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• 2009

In this paper, we have investigated about MgO thin films on Si(100) substrate by RF magnetron Sputtering. MgO thin films were affected by RF input power, gas pressure, gas composition, and substrate temperatures. So, we focused on most effective RF input power in deposition condition. Thickness of MgO thin films was measured by surface profiler. And structural analysis carried out by X-ray Diffraction(XRD). physical characteristic and thickness of thin films changed with RF input power.

• 전기학회논문지P
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• 제64권4호
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• pp.277-280
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• 2015

In this paper, we have studied the surface property and transmittance of n- and p-type thin film deposited on ITO substrate. In n-type samples, the average particle size was large and uniform as RF power was increased, and the best results were shown at the condition of the temperature of $300^{\circ}C$ and 200 W of RF power. The transmittance of the sample deposited for 20 minutes was 74.82% and the light wave was increased to 800 nm. In p-type samples, the results were 71.21% and 789 nm at the deposition condition of the RF power of 250 W and the temperature of $250^{\circ}C$.

• 전자공학회논문지 IE
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• 제45권4호
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• pp.7-10
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• 2008

본 연구에서는 load-pull 장비를 이용하여 hot carrier 현상에 따른 RF 전력 성능 저하를 측정 분석하였다. 스트레스를 인가한 주에 RF 전력 지수들은 감소하였으며, 고정 전압 조건에서 관찰한 SOIl MOSFET의 DC 성능 지수들 또한 hot carrier stress로 인하여 감소함을 할 수 있었다. 또한 Hot carrier stress로 인한 DC 성능 저하로 인하여 RF 전력 성능 저하의 감소를 알 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1695-1697
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• 2003

In this paper the emission properties of electrodeless fluorescent lamp were discussed using the inductively coupled plasma. To transmit the electromagnetic energy into the chamber a RF power of 13.56MHz was appied to the antenna and considering the Ar gas pressure and the RF electric power change, the emission spectrum, Ar-I line, luminance were investigated. At this time the input parameter for ICP RF plasma, Ar gas pressure and RF power were applied in the range of 10${\sim}$60m Torr, 10${\sim}$300W respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.755-758
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• 2000

YMnO$_3$films have been deposited with different Rf powers of 60W, 80W, 100W, and 120W. The structural properties of YMnO$_3$films on Si(100) were analysed by XRD(X-ray diffraction). The c-axis oriented peaks of YMnO$_3$were observed deposited in YMnO$_3$/Si(100) structure of RF power at 87$0^{\circ}C$ in oxygen ambient, and the peaks were enlarged by increasing The RF powers. The dielectric constant of the film deposited at 100W and 120W of RF power were about 19, 20 respectively.