• Title/Summary/Keyword: RF/V

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Extraction and Modeling of High-Temperature Dependent Capacitance-Voltage Curve for RF MOSFETs (고온 종속 RF MOSFET 캐패시턴스-전압 곡선 추출 및 모델링)

  • Ko, Bong-Hyuk;Lee, Seong-Hearn
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.10
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    • pp.1-6
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    • 2010
  • In this paper, RF Capacitance-Voltage(C-V) curve of short-channel MOSFET has been extracted from the room temperature to $225^{\circ}C$ using a RF method based on measured S-parameter data, and its high-temperature dependent characteristics are empirically modeled. It is observed that the voltage shift according to the variation of temperature in the weak inversion region of RF C-V curves is lower than the threshold voltage shift, but it is confirmed that this phenomenon is unexplainable with a long-channel theoretical C-V equation. The new empirical equation is developed for high-temperature dependent modeling of short-channel MOSFET C-V curves. The accuracy of this equation is demonstrated by observing good agreements between the modeled and measured C-V data in the wide range of temperature. It is also confirmed that the channel capacitance decreases with increasing temperature at high gate voltage.

The Korea Institute of Information, Electronics, and Communication Technology (RF Power 변화에 의한 CdS 박막 특성에 관한 연구)

  • Lee, Dal-Ho;Park, Jung-Cheul
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.2
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    • pp.122-127
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    • 2021
  • This paper produces CdS thin film using ITO glass as substrates. The MDS (Multiplex Deposition Sputter System) was used to produce devices by changing RF power and deposition time. The manufactured specimen was analyzed for its optical properties. The purpose of this paper is to find the fabrication conditions that can be applied to the photo-absorbing layer of solar cells. When RF power was 50W and deposition time was 10 minutes, the thickness was measured at 64Å. At 100W, the thickness was measured at 406Å and at 150 W, the thickness was measured at 889Å. Thin films were found to increase in thickness as RF power increased. As a result of the light transmittance measurement, 550-850nm was observed to have a transmittance of approximately 70% or more when the RF power was 50W, 100W, and 150W. Increasing RF power increased thickness and increased particle size, resulting in increased thin film density, resulting in reduced light transmittance. When RF power was 100W and deposition time was 15 minutes, the band gap was calculated at 3.998eV. When deposition time is 20 minutes, it is 3.987eV, 150W is 3.965eV at 15 minutes, and 3.831eV at 20 minutes. It was measured that the band gap decreased as the RF power increased. At XRD analysis, diffraction peaks at 2Θ=26.44 could be observed regardless of changes in RF power and deposition time. The FWHM was shown to decrease with increasing deposition time. And it was measured that the particle size increased as RF power was constant and deposition time was increased.

Effect of RF Power on the Structural, Optical and Electrical Properties of Amorphous InGaZnO Thin Films Prepared by RF Magnetron Sputtering (RF 마그네트론 스퍼터링으로 증착한 비정질 InGaZnO 박막의 구조적, 광학적, 전기적 특성에 미치는 RF 파워의 영향)

  • Shin, Ji-Hoon;Cho, Young-Je;Choi, Duck-Kyun
    • Korean Journal of Metals and Materials
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    • v.47 no.1
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    • pp.38-43
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    • 2009
  • To investigate the effect of RF power on the structural, optical and electrical properties of amorphous InGaZnO (a-IGZO), its thin films and TFTs were prepared by RF magnetron sputtering method with different RF power conditions of 40, 80 and 120 W at room temperature. In this study, as RF power during the deposition process increases, the RMS roughness of a-IGZO films increased from 0.26 nm to 1.09 nm, while the optical band-gap decreased from 3.28 eV to 3.04 eV. In the case of the electrical characteristics of a-IGZO TFTs, the saturation mobility increased from $7.3cm^2/Vs$ to $17.0cm^2/Vs$, but the threshold voltage decreased from 5.9 V to 3.9 V with increasing RF power. It is regarded that the increment of RF power increases the carrier concentration of the a-IGZO semiconductor layer due to the higher generation of oxygen vacancies.

Plasma control by tuning network modification in 4MHz ionized-physical vapor deposition (4MHz I-PVD장치에서 정합회로를 이용한 플라즈마 제어)

  • 주정훈
    • Journal of the Korean Vacuum Society
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    • v.8 no.1
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    • pp.75-82
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    • 1999
  • Ion energy is one of the crucial property in thin film deposition by internal ICP assisted I-PVD. As ion energy is determined by the difference between the plasma potential and the substrate bias potential, ICP excitation frequency was tested with medium frequency of 4 MHz and two types of tuning circuits, alternate and floating LC network with a biasing resistor, were tested. The results showed that plasma potential was less than 5 V in a range of Ar pressures, 5mTorr to 30 mTorr, at 4 MHz RF 600 W and 60 V of maximum RF antenna voltage was maintained either at RF input or output terminal. By proper control of RLC circuit installed after after RF antenna, 50V of RF induced voltage on RF antenna was obtained at 500W input power. The total impedance of RF antenna and plasma was around 10$\Omega$, and minimum RF voltage was obtained with a condition of lowest reactance at most 0.05$\Omega$.

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A Study on Improved SPICE MOSFET RF Model Considering Wide Width Effect (Wide Width Effect를 고려하여 개선된 SPICE MOSFET RF Model 연구)

  • Cha, Ji-Yong;Cha, Jun-Young;Lee, Seong-Hearn
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.2
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    • pp.7-12
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    • 2008
  • In this study, the wide width effect that the increasing rate of drain current and the value of cutoff frequency decrease with larger finger number is observed. For modeling this effect, an improved SPICE MOSFET RF model that finger number-independent external source resistance is connected to a conventional BSIM3v3 RF model is developed. Better agreement between simulated and measured drain current and cutoff frequency at different finger number is obtained for the improved model than the conventional one, verifying the accuracy of the improved model for $0.13{\mu}m$ multi-finger MOSFET.

2-Channel DC-DC Converter for OLED Display with RF Noise Immunity (RF 노이즈 내성을 가진 OLED 디스플레이용 2-채널 DC-DC 변환기)

  • Kim, Tae-Un;Kim, Hak-Yun;Choi, Ho-Yong
    • Journal of IKEEE
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    • v.24 no.3
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    • pp.853-858
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    • 2020
  • This paper proposes a 2-ch DC-DC converter for OLED display with immunity against RF noise inserted from communication device. For RF signal immunity, an input voltage variation reduction circuit that attenuates as much as the input voltage variation is embedded. The boost converter for positive voltage VPOS operates in SPWM-PWM dual mode and has a dead time controller to increase power efficiency. The inverting charge pump for negative voltage VNEG is a 2-phase scheme and operates in PFM using VCO to reduce output ripple voltage. Simulation results using 0.18 ㎛ BCDMOS process show that the overshoot and undershoot of the output voltage decrease from 10 mV to 2 mV and 5 mV, respectively. The 2-ch DC-DC converter has power efficiency of 39%~93%, and the power efficiency of the boost converter is up to 3% higher than the conventional method without dead time controller.

RF Magnetron Co-sputtering법으로 형성된 GZO & IGZO 박막의 불순물 농도에 따른 광학적 전기적 특성 연구

  • Hwang, Chang-Su;Park, In-Cheol;Kim, Hong-Bae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.85-85
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    • 2011
  • RF magnetron co-sputtering을 이용하여 RF power 및 공정 압력에 따라 GZO 및 IGZO 박막을 유리기판 위에 제작하고 투명전극으로 구조적, 광학적, 전기적 특성을 조사하였다. 박막 증착 조건의 초기 압력은 $1.0{\times}10^{-6}Torr$, 증착온도는 상온으로 고정하였으며 기판은 Corning 1737 유리기판을 사용하였다. 소결된 타겟으로 ZnO, $In_2O_3$$Ga_2O_3$을 이용하였으며, 각각의 타겟은 독립 된 RF파워를 변화시키며 투명전극의 성분비를 조절하였으며, 증착 압력은 10 m에서 100 mTorr까지, 기판과의 거리는 25 mm에서 65 mm까지 변화시키며 박막을 제작하였다. 유리기판 위에 불순물이 첨가된 모든 ZnO 박막에서 (002) 면의 우선배향성이 관찰되었고, 3.4eV에서 3.5eV 정도의 광학적 밴드갭을 가지며 80% 이상의 투과율을 나타내었다. GZO 박막의 경우 증착 조건에 따라 투명전극에 요구되는 $5*10^{-3}{\Omega}-cm$ 이하의 전기적특성을 가짐을 보였으며, gallium 성분이 0%에서 6%로 증가함에 따라 3.3eV에서 3.5eV로 blue-shift하였으며, 비저항은 0.02에서 $0.005{\Omega}cm$로 낮아졌으며 이동도는 $4.7cm^2V^{-1}s^{-1}$에서 $2.7cm^2V^{-1}s^{-1}$로 보이며 GZO 물질이 투명전극으로서 기존의 ITO 물질 대체 가능성을 확인하였다. IGZO 박막은 In과 Ga의 함량에 따라 저항률의 변화가 크게 나타났으며, In의 함량이 많을수록 이동도, 캐리어 농도의 증가로 저항률은 감소하였다.

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A Study on CdS Deposition using Sputtering (Sputtering을 이용한 CdS 증착에 관한 연구)

  • Lee, Dal-Ho;Park, Jung-Cheul
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.13 no.4
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    • pp.293-297
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    • 2020
  • This paper tried to find the best conditions that could be applied to solar cells by deposition of CdS thin film on ITO glass using multiplex displacement sputter system. RF power was changed to 50W, 100W, and 150W and sputtering time was set to 10 minutes. As a result of the measurement of transmittance, the average transmittance in the area of 400 to 800 nm was measured from 60% to 80% and the best characteristic was measured at 150W at 84%. The band gap was also measured at 3.762eV at 50W, 4.037eV at 100W and 4.052eV at 150W. In XRD analysis, even as RF power was increased, it was observed as a structure called Wurtzite (hexagonal) of CdS. And as RF power increased, the particles were large and uniformly deposited, but at 100W the particles were densely composed and dense. And the thickness measurement showed that the RF power increased uniformly.

Comparison of Drying Characteristics of Square Timber by Heated Platen and Radio-frequency/Vacuum Drying (큰 정각재의 가열판과 고주파 진공건조간 건조특성의 비교)

  • Jung, Hee-Suk;Kang, Wook;Lee, ChuI-Hyun
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.2
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    • pp.108-114
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    • 2002
  • Red pine(Pinus densiflora) square timbers with 14.0 cm and 16.5 cm of face size and 24 m long were dried in a vacuum-press kiln and in a radio-frequency/vacuum(RF/V) kiln to compare drying rate, moisture content(MC) distribution and specific energy. RF/V drying rate was higher than vacuum-press drying rate. The effect of size of cross section on the RF/V drying rates were more pronounced than those of vacuum-press drying. The longitudinal- and the transverse MC distribution of dried square timber showed convex profile for the vacuum-press drying and concave profile for the RF/V drying. Moisture gradient of width direction was similar to the thickness direction in vacuum-press dried square timber and was more slight than that of the thickness direction in the RF/V dried large square timber. The specific energy consumption curve increased as MC decreased. Specific energy(kWh/kg of water evaporated) of the vacuum-press process required more than that of the RF/V process.