• Title/Summary/Keyword: RF Heating

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A study on the AIN thin films fabricated by RF magnetron sputtering (RF Magnetron Sputtering 법으로 제조된 AIN 박막에 관한 연구)

  • 남창길;최승우;천희곤;조동율
    • Journal of the Korean Vacuum Society
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    • v.6 no.1
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    • pp.44-49
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    • 1997
  • AIN thin films were deposited on silicon and glass substrates by sputtering Al target and introducing mixed gases of argon and nitrogen into reactive RF magnetron sputter. The substrate was not heated to protect the PC (polycarbonate) substrate and the micro-sized pregroove morphology on the surface of PC substrate. But its temperature was around $100^{\circ}C$ due to the self-heating by plasma. The crystallinity, cross-section morphology and refractive index were characterized by changing various deposition parameters.

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Thermal and Stress Analysis of The Faraday Shield in KSTAR ICH System

  • Yoon, B.J.;Han, J.M.;Jeong, S.H.;Yoon, J.S.;Hong, B.G.
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05b
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    • pp.935-940
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    • 1998
  • The Korea Superconducting Tokamak Research (KSTAR) tokamak will have 6 MW of radio-frequency (rf) heating in the ion cyclotron range of frequencies (ICRF). The response of the antenna to the heat loads is analyzed and the resulting stresses in the Faraday shield during the normal operation is calculated. Various heat loading conditions including in the analyzes are the heat loads from the plasma, the ripple-trapped beam particles and the rf loss.

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The Design and Implementation of Heating Control System Based on Sensor Networks (센서 네트워크 기반의 난방제어시스템 설계 및 구현)

  • Lee, Jin-Kwan;Lee, Dae-Hyung;Lee, Chang-Bok;Lee, Jong-Chan;Park, Ki-Hong
    • Convergence Security Journal
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    • v.8 no.1
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    • pp.27-33
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    • 2008
  • The object of this paper is to design a heating control system based on sensor networks for the house, integrated with computing technology. The proposed system can manage the heating by sensing and analyzing the temperature and humidity in apartment house and others. This system also is capable of giving a comfortable circumstances because the interior of a house is in heated by the sensory temperature based control system.

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Voltage-Controlled Photonic RF True-Time Delay Using a Tapered Chirped Fiber Bragg Grating (테이퍼 구조를 갖는 광섬유 브래그 격자를 이용한 전압에 의하여 제어 가능한 광학적 실시간 지연 소자)

  • Chae, Ho-Dong;Lee, Sang-Shin
    • Korean Journal of Optics and Photonics
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    • v.16 no.2
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    • pp.133-137
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    • 2005
  • A photonic RF true-time delay using a tapered chirped fiber Bragg grating coated with a heating electrode has been proposed and fabricated. For an RF signal carried over an optical signal, the time delay has been achieved by controlling the voltage applied to the electrode and thus adjusting its reflection positions from the fiber grating through the thermooptic effect. It features continuous voltage-controlled operation, requiring no mechanical perturbation and no moving parts. The measured time delay was about 120 ps with the electrical power consumption of $250{\cal}mW$.

Effect of RF Bias on Electron Energy Distributions and Plasma Parameters in Inductively Coupled Plasma (유도 결합 플라즈마에서 플라즈마 변수와 전자 에너지 분포에 대한 극판 전력 인가의 영향)

  • Lee, Hyo-Chang;Chung, Chin-Wook
    • Journal of the Korean Vacuum Society
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    • v.21 no.3
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    • pp.121-129
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    • 2012
  • RF biased inductively coupled plasma (ICP) is widely used in semiconductor and display etch processes which are based on vacuum science. Up to now, researches on how rf-bias power affects have been focused on the controls of dc self-bias voltages. But, effect of RF bias on plasma parameters which give a crucial role in the processing result and device performance has been little studied. In this work, we studied the correlation between the RF bias and plasma parameters and the recent published results were included in this paper. Plasma density was changed with the RF bias power and this variation can be explained by simple global model. As the RF bias was applied to the ICP, increase in the electron temperature from the electron energy distribution was measured indicating electron heating. Plasma density uniformity was enhanced with the RF bias power. This study can be helpful for the control of the optimum discharge condition, as well as the basic understanding for correlation between the RF bias and plasma parameters.

Influences of Structural Features on Electrical Properties and Heating Characteristics of Al-Ta Alloy Thin Films (Al-Ta 합금박막의 구조적 인자가 전기적 특성 및 발열 특성에 미치는 영향)

  • Song Daegwon;Lee Jongwon;Park In Yong;Kim Kyujin
    • Journal of the Microelectronics and Packaging Society
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    • v.11 no.4 s.33
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    • pp.23-27
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    • 2004
  • The $Al_xTa_{1-x} (x=0.0{\~}1.0)$ alloy thin films were deposited by RF-magnetron sputtering system, and the crystal quality, surface morphology, and electrical properties were examined using XRD, AFM, 4-point probe techniques in this study. The thin films were grown according to the alloy compositions first, and the effects of film thickness and mask patterns were investigated afterwards. Also, the heating characteristics were examined by heat controller. The obtained results showed that the high electrical resistivity was obtained for Al content $x=6.63at\%$, and the even higher resistivity was accomplished for the samples with smaller thickness and narrower width. The heating temperature demonstrated the identical trend to the electrical properties, and the highest heating temperature ($400^{\circ}C$) and output power ($12.6W/cm^2$) were obtained for the sample with Al content $x=6.63\%$, film thickness d=500 nm, film width w=1.5 mm.

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Structure Optimization of ESD Diodes for Input Protection of CMOS RF ICs

  • Choi, Jin-Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.3
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    • pp.401-410
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    • 2017
  • In this work, we show that the excessive lattice heating problem due to parasitic pnp transistor action in the diode electrostatic discharge (ESD) protection device in the diode input protection circuit, which is favorably used in CMOS RF ICs, can be solved by adopting a symmetrical cathode structure. To explain how the recipe works, we construct an equivalent circuit for input human-body model (HBM) test environment of a CMOS chip equipped with the diode protection circuit, and execute mixed-mode transient simulations utilizing a 2-dimensional device simulator. We attempt an in-depth comparison study by varying device structures to suggest valuable design guidelines in designing the protection diodes connected to the $V_{DD}$ and $V_{SS}$ buses. Even though this work is based on mixed-mode simulations utilizing device and circuit simulators, the analysis given in this work clearly explain the mechanism involved, which cannot be done by measurements.

Effect of Post Deposition Annealing Temperature on the Structural, Optical and Electrical Properties of GZO Films Prepared by RF Magnetron Sputtering (RF 마그네트론 스퍼터링으로 증착 된 GZO 박막의 진공 열처리온도에 따른 구조적, 광학적, 전기적 특성 연구)

  • Kim, Daeil
    • Journal of the Korean Society for Heat Treatment
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    • v.24 no.4
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    • pp.199-202
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    • 2011
  • Ga doped ZnO thin films were deposited with RF magnetron sputtering on glass substrate without intentional substrate heating and then the effect of post deposition annealing temperature on the structural, optical and electrical properties of the films was investigated. The post deposition annealing process was conducted for 30 minutes in a vacuum of $1{\times}10^{-3}$ Torr and the vacuum annealing temperatures were 150 and $300^{\circ}C$, respectively. As increase annealing temperature, GZO films show the increment of the prefer orientation of ZnO (002) diffraction peak in the XRD pattern and the optical transmittance in a visible wave region was also increased, while the electrical sheet resistance was decreased. The figure of merit obtained in this study means that GZO films which vacuum annealed at $300^{\circ}C$ have the highest optoelectrical performance in this study.

Interstitial Hyperthermia by Radiofrequency Needle Electrode System : Phantom and Canine Brain Studies (8 MHz 라디오파를 이용한 자입식 온열치료 -조직등가물질을 통한 온도분포 및 개 뇌실질의 조직병리 변화에 관한 연구-)

  • Lee, Hyung-Sik;Chu, Sung-Sil;Sung, Jin-Sil;Suh, Chang-Ok;Kim, Gwi-Eon;Loh-John-Juhn-Kyu;Kim, Young-Soo;Kim, Sun-Ho;Chung, Song-Sup;Han, Eun-Kyung;Kim, Tae-Seung
    • Radiation Oncology Journal
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    • v.9 no.1
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    • pp.27-35
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    • 1991
  • An interstitial radiofrequency needle electrode system was constructed for interstitial heating of brain tissue. Radiofrequency electrodes with Thermotron RF 8 were tested in an agar phantom and in a normal canine brain to determine how variations in physical factors affected temperature distributions. Temperature distributions were checked after heating with 1 mm diameter needle electrode implants on the corners of 1 and 2 cm squares in a phantom and plot isotherms for various electrodes arrangement. We observed that the 1 cm square array would heat a volume with a 1.25 cm radius circular field cross section to therapeutic temperatures ($90\%$ relative SAR using Tm) and the 2 cm square array with a 1.75 cm radius rectangular field with central inhomogeneity. With 2 cm long electrode implants, we observed that the 1 cm square array would heat a 3 cm long sagittal section to therapeutic temperature ($90\%$ relative SAR using Tm). We found that radiofrequency electrodes could be selected to match the length of the heating area without affecting its performance. The histopathological changes associated with RF heating of normal canine brains have been correlated with thermal distributions. RF needle electrode heating was applied for 50min to generate tissue temperatures of $43^{\circ}C$. We obtained a quarter of the heated tissue material immediately after heating and sacrificed at intervals from $7\sim30$days. The acute stage (immediately after heating) was demonstrated by liquefactive necrosis, pyknosis of neuronal element in the gray matter and by some polymer-phonuclear leukocytes infiltration. The appearance of lipid-laden macrophages surrounding the area of liquefaction necrosis was demonstrated in all three sacrificed dogs. Mild gliosis occurring around the necrosis was demonstrated in the last sacrificed (Days 30) canine brain.

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Development of RF Stimulating Protocol for Effective Heat-Stimulus in Subcutaneous Tissue (피하에 효과적인 열 자극을 위한 고주파 자극 프로토콜 개발)

  • Myoung, Hyoun Seok;Lee, Dae Won;Kim, Han Sung;Lee, Kyoung Joung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.10
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    • pp.194-201
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    • 2012
  • Moxibustion is utilized not only to cure disease but also to increase immunity. However, it may lead to undesired effects including severe pains(blisters and burns) because of the difficulty of controlling heat intensity. To overcome these problems we developed the RF heat stimulation system which can control stimulus. Also, we developed the RF stimulation protocol for effective heat transfer in subcutaneous tissue of rabbit. RF stimulator consists of a medical RF capacitive heating device, isolation probe, isolation plate, negative pressure control part and temperature measurement part. For the designed stimulus protocol, we measured the temperature distribution on epidermis and in subcutaneous(5mm, 10mm) area of rabbit during moxibustion. A stimulation protocol was designed by controlling the ON/OFF duty ratio, repeating number, and energy of applied pulse to get the temperature distribution similar with that by moxibustion. In results, the correlation coefficients between temperature distribution by moxibustion and that of stimulator were 95% and 91% from 5mm and 10mm thick respectively. However, temperature distribution on epidermis by stimulator was remarkably lower than that of the moxibustion. Finally, the RF stimulation system showed that it can not only transfer effectively heat similar with moxibustion to the subcutaneous area, but also the influence by unwanted side effects can be minimized.