• 제목/요약/키워드: Work-function

검색결과 3,479건 처리시간 0.033초

PMOS에 적합한 Mo 전극의 전기적 화학적 안정성 (Electrical and Chemical Stability of Mo Gate Electrode for PMOS)

  • 노영진;이충근;홍신남
    • 대한전자공학회논문지SD
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    • 제41권4호
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    • pp.23-28
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    • 2004
  • 본 논문에서는 Mo을 PMOS의 금속 게이트로 사용하였을 때의 Mo의 특성에 대해서 연구 하였다. Mo을 게이트 물질로 사용한 MOS 커패시터를 제작하였고, 소자의 C-V 특성 곡선으로부터 일함수를 추출하였다. 그 결과 Mo 게이트는 PMOS에 적합한 일함수를 나타내는 것을 알 수 있었다. Mo의 전기적/화학적 안정성을 검증하기 위해서 600, 700, 800 그리고 900℃에서 급속 열처리를 수행하였으며 열처리 이후 유효 산화막의 두께와 일함수의 변화를 살펴보았다. 또한 900℃ 열처리 이후의 XRD 분석을 통해서 Mo 금속 게이트가 SiO₂에 대해서 안정하다는 것을 확인하였다. 4점 탐침기로 측정한 Mo 금속 게이트의 면저항은 10Ω/□ 미만으로 폴리 실리콘에 비해서 매우 작은 값을 나타냈다.

PNF 패턴에 기초한 탄력밴드 훈련이 척수손상 환자의 상지 기능에 미치는 영향 (The effect of elastic band based of PNF pattern on the U/E function in the spinal cord injury patient)

  • 신영일;이형수
    • The Journal of Korean Physical Therapy
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    • 제16권3호
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    • pp.152-160
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    • 2004
  • The purpose of this study was to investigate the effect of elastic band based of PNF pattern on the U/E function in the spinal cord injury patient. 11 subjects with spinal cord injury participated in this study. They took elastic band excercise 5 times per week for 8 weeks. One time excercise spent 35minutes. The therapeutic effect was evaluated by Cybex 6000, BTE Work Simulator, how many seconds they needed to walk 100 meters. 11 cases were examined before, after 8 week, elastic band excercise. The results of this study are as follows; 1. Isokinetic power by Cybex 6000 : The elbow flexion, shoulder flexion and extension were significant difference between test-retest(p<.05). but elbow extension were not significant difference between test-retest. 2. BTE Work Simulator : Wheelchair Propulsion and Steering Torque were significant difference between test-retest(p<.05). 3. Wheelchair Propulsion velocity : There were significant difference between test-retest(p<.05). The findings suggest that SCI patients can improve their Isokinetic power on shoulder and elbow joint, wheelchair propulsion and Steering Torque by BTE Work Simulator, Wheelchair Propulsion velocity through elastic band based of PNF pattern.

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Flexible Organic Light-Emitting Diodes Using Modified Graphene Anodes

  • 한태희;이영빈;최미리;우성훈;배상훈;홍병희;안종현;이태우
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2012년도 춘계학술발표대회
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    • pp.69.2-69.2
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    • 2012
  • Graphene films have a strong potential to replace indium tin oxide anodes in organic light-emitting diodes (OLEDs), to date. However, the luminous efficiency of OLEDs with graphene anodes has been limited by a lack of efficient methods to improve the low work function and reduce the sheet resistance of graphene films to the levels required for electrodes. Here, we fabricate flexible OLEDs by modifying the graphene anode to have a high work function and low sheet resistance, and thus achieve extremely high luminous power efficiencies (37.2 lm/W in fluorescent OLEDs, 102.7 lm/W in phosphorescent OLEDs), which are significantly higher than those of optimized devices with an indium tin oxide anode (24.1 lm/W in fluorescent OLEDs, 85.6 lm/W in phosphorescent OLEDs). We also fabricate flexible white OLED lighting devices using the graphene anode. These results demonstrate the great potential of graphene anodes for use in a wide variety of high-performance flexible organic optoelectronics.

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표면개질된 금 전극의 일함수 조절을 통한 고성능 유기박막 트랜지스터 개발 (Control of the Gold Electrode Work Function for High Performance Organic Thin Film Transistors)

  • 박영돈
    • 공업화학
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    • 제23권3호
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    • pp.289-292
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    • 2012
  • 용액공정이 가능한 저분자 유기반도체, triethylsilylethynyl anthradithiophene (TES ADT)을 기반으로 한 유기박막 트랜지스터에서 금 전극의 일함수를 제어하기 위해 표면을 자기조립 단분자막(self-assembled monolayers, SAMs)으로 개질하였다. Benzothiol (BT)과 pentafluorobenzothiol (PFBT) 자기조립 단분자막을 이용해 금 전극의 일함수를 조절하고 이를 통해 TES ADT의 HOMO 준위에 대한 정공주입장벽을 최소화 하고자 하였다. 또한, solvent annealing 후처리 공정을 통해 TES ADT 박막의 결정성을 향상시켰고, 이를 PFBT로 개질된 금 전극을 기반으로 한 유기박막 트랜지스터에 적용한 경우 $0.05\;cm^2/Vs$의 높은 전계효과 이동도와 $10^6$의 높은 점멸비를 보고하였다.

서로 다른 소스/드레인 전극물질을 이용한 비정질 In-Ga-Zn-O 박막트랜지스터 성능향상 (Performance Improvement of Amorphous In-Ga-Zn-O Thin-film Transistors Using Different Source/drain Electrode Materials)

  • 김승태;조원주
    • 한국전기전자재료학회논문지
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    • 제29권2호
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    • pp.69-74
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    • 2016
  • In this study, we proposed an a-IGZO (amorphous In-Ga-Zn-O) TFT (thin-film transistor) with off-planed source/drain structure. Furthermore, two different electrode materials (ITO and Ti) were applied to the source and drain contacts for performance improvement of a-IGZO TFTs. When the ITO with a large work-function and the Ti with a small work-function are applied to drain electrode and source contact, respectively, the electrical performances of a-IGZO TFTs were improved; an increased driving current, a decreased leakage current, a high on-off current ratio, and a reduced subthreshold swing. As a result of gate bias stress test at various temperatures, the off-planed S/D a-IGZO TFTs showed a degradation mechanism due to electron trapping and both devices with ITO-drain or Ti-drain electrode revealed an equivalent instability.

습식공정으로 형성된 구리산화물 나노와이어의 전계방출특성 향상 (Enhancement of Field Emission Characteristics of CuO Nanowires Formed by Wet Chemical Process)

  • 성우용;김왈준;이승민;이호영;박경호;이순일;김용협
    • 한국표면공학회지
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    • 제37권6호
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    • pp.313-318
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    • 2004
  • Vertically-aligned and uniformly-distributed CuO nanowires were formed on copper-coated Si substrates by wet chemical process, immersing them in a hot alkaline solution. The effects of hydrogen plasma treatment on the field emission characteristics of CuO nanowires were investigated. It was found that hydrogen plasma treatment enhanced the field emission properties of CuO nanowires by showing a decrease in turn-on voltage, and an increase in emission current density, and stability of current-voltage curves. However, the excessive hydrogen plasma treatment made the I-V curves unstable. It was confirmed by XPS (X-ray Photoelectron Spectroscopy) analysis that hydrogen plasma treatment deoxidized CuO nanowires, thereby the work function of the nanowires decreased from 4.35 eV (CuO) to 4.1 eV (Cu). It is thought that the decrease in the work function enhanced the field emission characteristics. It is well-known that the lower the work function, the better the field emission characteristics. The results suggest that the hydrogen plasma treatment is very effective in achieving enhanced field emission properties of the CuO nanowires, and there may exist an optimal hydrogen plasma treatment condition.

금속(Al, Cr, Ni)의 일함수를 고려한 쇼트키 장벽 트랜지스터의 전기-광학적 특성 (Metal work function dependent photoresponse of schottky barrier metal-oxide-field effect transistors(SB MOSFETs))

  • 정지철;구상모
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.355-355
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    • 2010
  • We studied the dependence of the performance of schottky barrier metal-oxide-field effect transistors(SB MOSFETs) on the work function of source/drain metals. A strong impact of the various work functions and the light wavelengths on the transistor characteristics is found and explained using experimental data. We used an insulator of a high thickness (100nm) and back gate issues in SOI substrate, subthreshold swing was measured to 300~400[mV/dec] comparing with a ideal subthreshold swing of 60[mV/dec]. Excellent characteristics of Al/Si was demonstrated higher on/off current ratios of ${\sim}10^7$ than others. In addition, extensive photoresponse analysis has been performed using halogen and deuterium light sources(200<$\lambda$<2000nm).

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하지의 닫힌 사슬 운동시 대퇴부 테이핑 적용이 등속성 근기능에 미치는 영향 (The effects of kinesio taping of thigh muscle on isokinetic muscular function during closed kinetic chain exercise of lower extremity)

  • 김상엽;윤영제;최원제
    • PNF and Movement
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    • 제8권3호
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    • pp.9-16
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    • 2010
  • Purpose : The purpose of this study was to investigate effects of kinesio taping of thigh muscle on isokinetic muscular function during closed kinetic chain exercise of lower extremity. Methods : Twenty healthy males were participated in this study. The isokinetic muscular function of closed kinetic chain were measured for peak torque, peak torque % body weight, average power, max rep tot work before and after application of kinesio taping on thigh muscles. Results : At $60^{\circ}/s$ peak force and peak force % body weight were significant increased in both extension(p<0.01) and flexion(p<0.001) after applying kinesio taping. At $180^{\circ}/s$ average power was significant increased in both extension and flexion after applying taping(p<0.001). At $240^{\circ}/s$ max rep tot work was significant increased in both extension(p<0.001) and flexion(p<0.05). Conclusion : This study suggests that application of kinesio taping on thigh muscle was more effective to improve isokinetic muscular function in closed kinetic chain exercise of lower extremity.

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Modulation Transfer Function (MTF) Measurement For 1 m High Resolution Satellite Images such as KOMPSAT-2 U sing Edge Function

  • Song Jeong-Heon;Lee Dong-Han;Lee Sun-Gu;Seo Du-Ceon;Park Soo-Young;Lim Hyo-Suk;Paek Hong-Yul
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.482-484
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    • 2005
  • The Modulation Transfer Function (MTF) is commonly used to characterize the spatial quality of imaging systems. This work is the attempt to measure the MTF at Nyquist frequency of the satellite imaging system what has 1m spatial resolution for KOMPSAT-2 image using the edge function. Artificial tarp targets are used in this study. A type of this tarp edge consists of two adjacent uniform bright and dark sides commonly used to test the performance of an optical system in edge function. The results from this work demonstrate the potential applicability of this method to estimate the response characteristics for KOMPSAT-2 that is scheduled to be launched.

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기능전환에 따른 동사무소 공간의 적정규모에 관한 연구 (A Study on the appropriateness of Public Facilities Scale)

  • 이정호
    • 한국주거학회논문집
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    • 제16권1호
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    • pp.65-72
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    • 2005
  • With the changing consciousness of community people and the rising standard of living, there has recently been an emphasis on the creation of public facilities' new functions and their role as local community facilities. This changing trends are accordingly requiring a change in spatial structure of the public facilities. In this study, an analysis was conducted with 24 public facilities situated in the Buk-gu district of Daegu to identify the adequacy of their space scale after functional variation. The results of this study are summarized as follows. 1) The site area of public facilities has been being widened after functional variation since more spaces are needed to provide an outdoor resting space with community people, expand a parking space, and operate a community center. 2) The factors that had a direct effect on the change in the use of space are the reduced space for administrative work and the expanded scope of the community center's function. Specifically, the areas of activities for civil service and administrative work and for reserve forces have been reduced due to reduction of function, and floor division by each function group has been becoming stricter due to addition of a community center's function. 3) It was shown that in terms of the space for functions of public facilities, spaces for civil service and waiting have increased mostly after function variation. After functional variation, the scale of spaces for civil service and administrative work has been being planned within the range of $200\~300 m^2$, regardless of the number of population to be covered by public facilities. 4) The space for public use is showing the greatest increase in public facilities which have been built after functional variation. The major factors seem to be the increased moving passages, the expanded convenient facilities for community people, and the increased convenient facilities for disabled. Facilities scale plans have been being made more systematically, compared to the conventional facilities.