• 제목/요약/키워드: Interface stability

검색결과 763건 처리시간 0.028초

박막 게이트 절연체 위에서 Ta-Mo 합금의 안정성 (Stability of Ta-Mo alloy on thin gate dielectric)

  • 이충근;강영섭;서현상;홍신남
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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    • pp.9-12
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    • 2004
  • This paper investigated the stability of Ta-Mo alloy on thin gate dielectric. Ta-Mo alloy was deposited by using co-sputtering process after thermal growing of 3.4nm and 4.2nm silicon dioxide. When the sputtering power of Ta and Mo were 100W and 70W, respectively, the suitable work function for NMOS gate electrode, 4.2eV, could obtain. To prove interface thermal stability of thin film gate dielectric and Ta-Mo alloy, rapid thermal annealing was performed at $600^{\circ}C$ and $700^{\circ}C$ for 10sec in Ar ambient. The results of interface reaction were surveyed by change of silicon dioxide thickness and work function after annealing process. Also, the reliability of alloy gate and gate dielectric could be confirmed by quantity of leakage current. Ta-Mo alloy was showed low sheet resistance and thermal stability, namely, little change of gate dielectric and work function, after $700^{\circ}C$ annealing process.

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점성포텐셜유동을 이용한 이상유동장의 표면안정성 해석 (Stability analysis of gas-liquid interface using viscous potential flow)

  • 김형준;권세진
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.3033-3038
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    • 2007
  • In this research, Rayleigh instability of gas-liquid flow in annular pipe is studied in film boiling using viscous potential flow. Viscous potential flow is a kind of approximation of gas-liquid interface considering velocity field as potential including viscosity. A dispersion relation is obtained including the effect of heat and mass transfer and viscosity. New expression for dispersion relation in film boiling and critical wave number is obtained. Viscosity and heat and mass transfer have a stabilizing effect on instability and its effect appears in maximum growth rate and critical wave number. And the existence of marginal stability region is shown.

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LQG/LTR을 이용한 Haptic Interface의 강인제어 (Robust Control of a Haptic Interface Using LQG/LTR)

  • 이상철;박헌;이수성;이장명
    • 제어로봇시스템학회논문지
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    • 제8권9호
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    • pp.757-763
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    • 2002
  • A newly designed haptic interface enables an operator to control a remote robot precisely. It transmits position information to the remote robot and feeds back the interaction force from it. A control algorithm of haptic interface has been studied to improve the robustness and stability to uncertain dynamic environments with a proposed contact dynamic model that incorporates human hand dynamics. A simplified hybrid parallel robot dynamic model fur a 6 DOF haptic device was proposed to from a real time control system, which does not include nonlinear components. LQC/LTR scheme was adopted in this paper for the compensation of un-modeled dynamics. The recovery of the farce from the remote robot at the haptic interface was demonstrated through the experiments.

Gd-doped $CeO_2$ 와 Sr-doped $LaMnO_3$ 분말의 합성 및 그 계면에서의 상 안정성 연구 (A Study on the Synthesis of Gd-doped $CeO_2$ and Sr-doped $LaMnO_3$ Powders and Phase Stability in Their Interface)

  • 정승훈;김남진;이덕열
    • 한국세라믹학회지
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    • 제34권6호
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    • pp.652-658
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    • 1997
  • The phase stability in the interface of Sr-doped LaMnO3(LSM)/Gd-doped CeO2(CGO) was examined in this study in order to check the feasibility of using LSM as the cathode material in a low-temperature SOFC(solid oxide fuel cell) using CGO as the electrolyte. For the purpose, CGO powders of Ce0.82Gd0.18O0.91 and two LSM powders having different compositions, La0.9Sr0.1MnO3(LSM10) and La0.5Sr0.5MnO3(LSM50), were synthesized using Pechini method. Then, specimens having the LSM/CGO interface were prepared, heat-treated at 130$0^{\circ}C$ for up to 3 days, and analyzed by XRD and STEM/EDX. Face-centered cubic CGO powders of less than 10 nm size were obtained by calcination of polymeric precursor formed in the process at 45$0^{\circ}C$. Higher calcination temperature of $700^{\circ}C$ was necessary for monoclinic LSM10 and cubic LSM50 powders. LSM powders were coarser than CGO and observed to be in the range of 50~100 nm. No trace of LSM-CGO interaction product was found in the XRD pattern. Also it was known from the concentration profile in the vicinity of the interface that interdiffusion was occurred over only a small penetration depth of ~100 nm order.

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터치스크린 기반 항해 시스템을 위한 사용자 인터페이스 실험 모델 설계 (User Interface Experiment Model Design for Touch-Screen Based on Navigation System)

  • 전현민;안재용;오승엽;박범
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제3권11호
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    • pp.503-510
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    • 2014
  • 전자통신 기술의 발달로 인해 선박 항해 장비들도 아날로그에서 디지털로 변경되어 통합 운용되고 있으며, 터치스크린 기반의 항해 인터페이스가 주목받고 연구 개발되고 있는 추세이다. 하지만, 항해 중에 파도와 같은 외부적인 환경요인으로부터 영향을 받기 때문에 잘못된 조작으로 인하여 위험한 해양사고가 발생할 수 있는 문제점을 갖고 있지만, 이를 고려한 체계적인 연구가 이루어지지 않고 있다. 본 논문에서는 터치스크린 입력상의 외부 환경을 고려한 안정성을 검증하는 실험 모델을 제안한다. 또한 제안하는 실험 모델을 통하여 터치스크린 인터페이스에서 버튼의 크기와 입력 지연시간을 부여하는 것이 효과가 있는지 확인하는 모의실험을 하였다. 제안된 실험 모델을 통한 분석을 통하여, 선박 전체 시스템의 안정성을 증진시킬 수 있는 사용자 오류에 견고한 터치스크린 인터페이스 연구에 크게 기여할 수 있을 것이다.

무시멘트형 인공고관절 대치술후 초기의 경계면 미세운동의 3차원 FEM 연구 (A Study on the Interface Micromotions of Cementless Artificial Hip Replacement by Three-Dimensional FEM)

  • 김성곤;채수원;최형연
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1994년도 추계학술대회
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    • pp.71-74
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    • 1994
  • In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony ingrowth and secondary long term fixation. Bone ingrowth depends strongly on relative micromotion and stress distributions at the interface. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone-prosthesis interface, Hence an accurate evaluation of interface behavior and stress/strain fields in the bone implant system may be relevant for better understanding of clinical situations and improving THA design. However, complete evaluation of load transfer in the bone remains difficult to assess experimentally, Hence, recently finite element method (FEM) was introduced in orthopaedic research field to fill the gap due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional numerical finite element model which is composed of totally 1179 elements off and 8 node blick. We also analyzed the micromotions at the bone-stem interface and mechanical behavior of existing bone prosthesis for a loading condition simulating the single leg stance. The result indicates that the values of relative motion for this well fit Multilock stem were $150{\mu}m$ in maximum, $82{\mu}m$ in minimum, and the largest relative motion developed in medial region of proximal femur with anterior-posterior direction. The proximal region of the bone was much larger in motion than the distal region and the stress pattern shows high stress concentration on the cortex near the tip of the stem. These findings indicates that the loading in the proximal femoral bone in the early postoperative situation can produce micromotions on the interface and clinically cementless TEA patient should not be allowed weight bearing strictly early in the postoperative period.

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Improvement in the bias stability of zinc oxide thin-film transistors using an $O_2$ plasma-treated silicon nitride insulator

  • 김웅선;문연건;권태석;박종완
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.180-180
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    • 2010
  • Thin film transistors (TFTs) based on oxide semiconductors have emerged as a promising technology, particularly for active-matrix TFT-based backplanes. Currently, an amorphous oxide semiconductor, such as InGaZnO, has been adopted as the channel layer due to its higher electron mobility. However, accurate and repeatable control of this complex material in mass production is not easy. Therefore, simpler polycrystalline materials, such as ZnO and $SnO_2$, remain possible candidates as the channel layer. Inparticular, ZnO-based TFTs have attracted considerable attention, because of their superior properties that include wide bandgap (3.37eV), transparency, and high field effect mobility when compared with conventional amorphous silicon and polycrystalline silicon TFTs. There are some technical challenges to overcome to achieve manufacturability of ZnO-based TFTs. One of the problems, the stability of ZnO-based TFTs, is as yet unsolved since ZnO-based TFTs usually contain defects in the ZnO channel layer and deep level defects in the channel/dielectric interface that cause problems in device operation. The quality of the interface between the channel and dielectric plays a crucial role in transistor performance, and several insulators have been reported that reduce the number of defects in the channel and the interfacial charge trap defects. Additionally, ZnO TFTs using a high quality interface fabricated by a two step atomic layer deposition (ALD) process showed improvement in device performance In this study, we report the fabrication of high performance ZnO TFTs with a $Si_3N_4$ gate insulator treated using plasma. The interface treatment using electron cyclotron resonance (ECR) $O_2$ plasma improves the interface quality by lowering the interface trap density. This process can be easily adapted for industrial applications because the device structure and fabrication process in this paper are compatible with those of a-Si TFTs.

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