• 제목/요약/키워드: Carrier Direction

검색결과 148건 처리시간 0.025초

Strained-Si PMOSFET에서 디지털 및 아날로그 성능의 캐리어 방향성에 대한 의존성 (Dependence of Analog and Digital Performance on Carrier Direction in Strained-Si PMOSFET)

  • 한인식;복정득;권혁민;박상욱;정의정;신홍식;양승동;이가원;이희덕
    • 대한전자공학회논문지SD
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    • 제47권8호
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    • pp.23-28
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    • 2010
  • 본 논문에서는 각각 다른 캐리어 방향성을 가지는 strained-silicon PMOSFET에서 소자의 디지털 및 아날로그 성능을 비교 평가 하였다. 캐리어 방향이 <100>을 갖는 소자의 경우 이동도 향상에 의해서 <110> 방향의 소자 보다 우수한 드레인 구동 전류 및 출력저항 특성을 보이지만, NBTI 신뢰성과 소자의 matching 특성은 반대로 다소 열화 됨을 확인 하였다. 따라서 나노미터급 CMOSFET에서 캐리어 방향성을 이용한 이동도 향상 기술의 적용을 위해서는 DC 성능을 비롯한 신뢰성 및 아날로그 특성을 모두 고려하는 것이 반드시 필요하다고 할 수 있다.

PMOSFET에서 채널 방향에 대한 소자 성능 의존성 (Dependence of Device Performance and Reliability on Channel Direction in PMOSFET's)

  • 복정득;박예지;한인식;권혁민;박병석;박상욱;임민규;정의선;이정환;이희덕
    • 한국전기전자재료학회논문지
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    • 제23권6호
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    • pp.431-435
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    • 2010
  • In this paper, we investigated the dependence of device performance and hot carrier lifetime on the channel direction of PMOSFET. $I_{D.sat}$ vs. $I_{Off}$ characteristic of PMOSFET with <100> channel direction is greater than that with <110> channel direction because carrier mobility of <100> channel direction is greater than that of <110> channel direction. However, hot carrier lifetime for <110> channel direction is much lower than that with <110> channel due to the greater impact ionization rate in the <100> channel direction. Therefore, concurrent consideration of reliability characteristics and device performance is necessary for channel strain engineering of MOSFETs.

Investigation of wearing methods of a baby carrier on muscle activation during trunk flexion-extension in healthy women

  • Park, Hae-Kwang;Shin, Hwa-Kyung;Nam, Ki-Seok
    • Physical Therapy Rehabilitation Science
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    • 제9권1호
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    • pp.36-42
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    • 2020
  • Objective: Many caregivers often carry infants using baby carriers until they are approximately 36 months old. The purpose of this study was to compare the muscular activity of the trunk and lower leg muscles during trunk flexion-extension movements in correspondence to various wearing methods of a baby carrier blanket. Design: Cross-sectional study. Methods: Sixteen healthy adult women were to wear baby carrier blankets in five different ways in terms of direction and height, followed by flexion-extension of the trunk. Erector spinae (ES), rectus abdominis, rectus femoris (RF), biceps femoris (BF) muscle activities and triaxial acceleration of trunk were investigated. Results: The front-wearing method of the baby carrier blanket increased the muscular activity of the ES muscle, and wearing the baby carrier blanket at waist height in the same direction was significantly higher than wearing it at pelvic height (p<0.05). As the angle of flexion increased during trunk flexion-extension, the muscle activity of the ES, BF, and the RF increased. There was a greater increase in muscle activity of the ES and the BF during extension compared to flexion (p<0.05). Conclusions: If it is difficult to wear a baby carrier blanket due to lumbar pain, it is recommended to lower the wearing height of the baby carrier to the pelvic level so that the external load can be transferred to the lower extremity. In addition, it appears to be necessary to hold the baby and distribute the load onto the waist through proper body control when performing flexion-extension movements of the trunk. More objective and scientific research that includes various daily tasks and evaluation methods are needed.

저가항공 관련 국내학술지 네트워크 텍스트 분석 (Bibliometric Network Analysis on Low Cost Carrier Research)

  • 나진성;최동현
    • 한국항공운항학회지
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    • 제23권1호
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    • pp.14-23
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    • 2015
  • This study applied the network text analysis to reveal the scope and trends of low cost carrier studies. We analyzed low cost carrier research published in Korean journals and news articles. The results showed that there are three clusters in terms of research topics. First dimension consists of articles investigating growth in the low cost carrier industry. The second dimension is associated with service characteristics. The last dimension has strong ties organizational and human resource dimension. We run Krkwic, Krtitle, Netdraw, and Ucinet 6.0 to conduct the network text analysis. This study suggests the direction of low cost carrier research in the future.

Effects of Carrier Leakage on Photoluminescence Properties of GaN-based Light-emitting Diodes at Room Temperature

  • Kim, Jongseok;Kim, Seungtaek;Kim, HyungTae;Choi, Won-Jin;Jung, Hyundon
    • Current Optics and Photonics
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    • 제3권2호
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    • pp.164-171
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    • 2019
  • Photoluminescence (PL) properties of GaN-based light-emitting diodes (LEDs) were analyzed to study the effects of carrier leakage on the luminescence properties at room temperature. The electrical leakage and PL properties were compared for LEDs showing leakages at forward bias and an LED with an intentional leakage path formed by connecting a parallel resistance of various values. The leakages at the forward bias, which could be observed from the current-voltage characteristics, resulted in an increase in the excitation laser power density for the maximum PL efficiency (ratio of PL intensity to excitation power) as well as a reduction in the PL intensity. The effect of carrier leakages on PL properties was similar to the change in PL properties owing to a reduction of the photovoltage by a reverse current since the direction of the carrier movement under photoexcitation is identical to that of the reverse current. Valid relations between PL properties and electrical properties were observed as the PL properties deteriorated with an increase in the carrier leakage. The results imply that the PL properties of LED chips can be an indicator of the electrical properties of LEDs.

Characterization of carrier transport and trapping in semiconductor films during plasma processing

  • Nunomura, Shota;Sakata, Isao;Matsubara, Koji
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.391-391
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    • 2016
  • The carrier transport is a key factor that determines the device performances of semiconductor devices such as solar cells and transistors [1]. Particularly, devices composed of in amorphous semiconductors, the transport is often restricted by carrier trapping, associated with various defects. So far, the trapping has been studied for as-grown films at room temperature; however it has not been studied during growth under plasma processing. Here, we demonstrate the detection of trapped carriers in hydrogenated amorphous silicon (a-Si:H) films during plasma processing, and discuss the carrier trapping and defect kinetics. Using an optically pump-probe technique, we detected the trapped carriers (electrons) in an a-Si:H films during growth by a hydrogen diluted silane discharge [2]. A device-grade intrinsic a-Si:H film growing on a glass substrate was illuminated with pump and probe light. The pump induced the photocurrent, whereas the pulsed probe induced an increment in the photocurrent. The photocurrent and its increment were separately measured using a lock-in technique. Because the increment in the photocurrent originates from emission of trapped carriers, and therefore the trapped carrier density was determined from this increment under the assumption of carrier generation and recombination dynamics [2]. We found that the trapped carrier density in device grade intrinsic a-Si:H was the order of 1e17 to 1e18 cm-3. It was highly dependent on the growth conditions, particularly on the growth temperature. At 473K, the trapped carrier density was minimized. Interestingly, the detected trapped carriers were homogeneously distributed in the direction of film growth, and they were decreased once the film growth was terminated by turning off the discharge.

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합성절차에 따른 1차원 ZnO 나노구조의 형태조절과 특성평가 (Shape Control and Characterization of One-dimensional ZnO Nanostructures through the Synthesis Procedure)

  • 공보현;박태은;조형균
    • 한국전기전자재료학회논문지
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    • 제19권1호
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    • pp.13-17
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    • 2006
  • The one-dimensional ZnO nanostructures prepared through thermal evaporation under various cooling down procedures by changing the flow rates of the carrier gas and the reactive gas were investigated. The nanorod structures were changed into the nanonail types with a broad head through the reduction of the flow rate of the carrier gas. The decrease of the reactive gas reduced the length of the nail heads due to the limited mass transport of reactive gas. The intensity ratio of the ultraviolet emission/green emission of photoluminescence was proportional to the length of the broad head showing a larger surface area. The vertically aligned nanostructures were grown along the [0001] direction of ZnO regardless of the aligned directions. The crystal direction of the nanostructures was determined by that of the initial ZnO crystal.

반송용 리니어 DC 모터의 듀얼모드 위치제어에 관한 연구 (A study on the Dual mode Control of Linear DC motor for Carrier)

  • 임달호;윤상백;이우균
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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    • pp.83-85
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    • 1994
  • This paper describes the dual mode control of the LDM(Linear DC motor) for carrier. The dual mode control consists of seek and analogue control. In seek mode, LDM is moved in the shortest time by switching line, and in analogue mode keeps at origion with high accuracy. We proposed different switching line method according to driving direction.

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Ionospheric Storm Detection Method Using Multiple GNSS Reference Stations

  • Ahn, Jongsun;Lee, Sangwoo;Heo, Moonbeom;Son, Eunseong;Lee, Young Jae
    • Journal of Positioning, Navigation, and Timing
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    • 제8권3호
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    • pp.129-138
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    • 2019
  • In this work, we propose detection method for ionosphere storm that occurs locally using widespread GNSS reference stations. For ionosphere storm detection, we compare ionosphere condition with other reference stations and estimate direction of movement based on ionosphere time variation. The method use carrier phase measurement of dual frequency, for accuracy and precision of test statistics, are evaluated with multiple GNSS reference stations data.