• 제목/요약/키워드: Anisotropic characteristic

검색결과 90건 처리시간 0.021초

Anisotropic etching of polysilicon in a $Cl_2/CH_3Br/O_2$ Plasma

  • Yi, Whi-Kun
    • Journal of Korean Vacuum Science & Technology
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    • 제3권1호
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    • pp.24-29
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    • 1999
  • The characteristic behaviors of CH3Br were examined first for the dry etching of polysilicon in a Cl2/CH3Br/O2 plasma. CH3Br is revealed one of the excellent additive gases to control anisotropy of etching profile and to give no undercutting for various typed of polysilicons. CH3Br acts as a passivation precursor on the side wall in etch cavity by forming polymer-like films such as CHxBry(x+y=1,2). The decrease of etch selectivity due to the reaction if the C-containing species from CH3Br with the surface O atoms of SiO2 was overcome by the addition of O2 into plasma, resulting that the selectivity increased by 2~3 times. According to the results of optical emission signals, CH3Br should be dissociated into several fragments to give more hydrogen atoms than bromine atoms in our helical resonator system.

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p+ 박막을 전극으로 한 정전형 마이크로 구동기의 제작 (Fabrication of an Electrostatic Micro Actuator Using p+ Diaphragm As an Electrode)

  • 한상우;양의혁;양상식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 A
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    • pp.141-143
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    • 1994
  • In this paper, an electrostatic micro-actuator is fabricated using flat p+ diaphragm. To avoid the buckling of the flat p+ diaphragm, the processes are designed appropriately. The fabrication processes of the actuator are the anisotropic etching with EPW, the boron diffusion process, Al deposition and the silicon to glass bonding using the negative photoresist. The distance between the p+ and Al electrodes is $10{\mu}m$, and the thickness of the p+ diaphragm is $2{\mu}m$. The measurement of the characteristic of the actuator is performed at 50V. The center displacement of the diaphragm is $1.5{\mu}m$ at 10Hz. In comparison with the experimental data of the actuator with corrugated diaphragm, it is confirmed that the actuator with flat diaphragm is more effective than that with corrugated one in the small deflection region.

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대구지하철 굴착암에 대한 재활용 평가 (Evaluation on Reuse of Excavated Rocked from Construction Field of Taegu Subway)

  • 차완용;이상호;김영수;방인호
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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    • pp.252-257
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    • 1999
  • The distinguished geological characteristic of Taegu area is consist of anisotropic shale or sedimentary rock. Therefore if rocks are used for construction, it would've some difficulties of reuse showing the aspect of resource engineering. We made physical and mechanic properties for rock discrimination and then whether it had utilization worth or not. So we studied the engineering propriety through the aggregate tests based on rock's in laboratory. The last passed aggregate were D, E and B1 at KS and the rest couldn't use the place where weather phenomenon is caprice. This sis for base-line data of aggregate development research before the porpriety investigation for aggreagte of excavated rock in Taegu area.

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비등방성을 고려한 고온초전도 솔레노이드 마그네트의 임계 전류 특성 (Critical current characteristic of solenoid magnet with anisotropic HTS tapes)

  • 김준선;나완수;권영길;손명환;류강식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 B
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    • pp.966-968
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    • 2000
  • 비등방성 고온 초전도 테이프는 자장의 세기뿐만 아니라 방향에 따라서도 임계 전류 값이 영향을 받는다. 이러한 비등방성 고온 초전도 테이프로 권선된 솔레노이드 마그네트의 임계 전류 특성 및 임계 전류를 결정짓는 위치를 알아내기 위해, 솔레노이드 모델의 자장 분포 및 수직 자장 성분과 평행 자장 성분을 구하고 임계 전류는 비선형 방정식을 수치적인 방법을 이용하여 예측해보았다.

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선박용 강재의 피로파괴거동의 실험적 연구 (An Experimental Study on Fatigue Fracture Behavior of Steel for Merchant Ships)

  • 한문식;김상철
    • 대한조선학회지
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    • 제25권1호
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    • pp.21-32
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    • 1988
  • An experimental study was carried out to identify the fatigue fracture behavior of steel for merchant ships. The bending and shear loads were applied simultaneously on the specimens to simulate of real load condition for a ship. The effects of the stress intensity factor under mode I with mode II loading condition on the initiation and the propagation of a crack were investigated, with particular emphasis on mode II. When the $K_{II}$ stress intensity factor in mode II was applied under mode I loading condition, the propagation behavior of a crack is to be affected mainly by the anisotropic characteristic of materials.

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마스크리스 나노 패턴제작을 위한 나노스크래치 된 Si(100) 표면의 식각 마스크 효과에 관한 연구 (Study on the Masking Effect of the Nanoscratched Si (100) Surface and Its Application to the Maskless Nano Pattern fabrication)

  • 윤성원;강충길
    • 한국정밀공학회지
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    • 제21권5호
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    • pp.24-31
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    • 2004
  • Masking effect of the nanoscratched silicon (100) surface was studied and applied to a maskless nanofabrication technique. First, the surface of the silicon (100) was machined by ductile-regime nanomachining process using the scratch option of the Nanoindenter${ \circledR}$ XP. To clarify the possibility of the nanoscratched silicon surfaces for the application to wet etching mask, the etching characteristic with a KOH solution was evaluated at room temperature. After the etching process, the convex nanostructures were made due to the masking effect of the mechanically affected layer. Moreover, the height and the width of convex structures were controlled with varying normal loads during nanoscratch.

등가강성과 Shell 요소를 이용한 분산형 고속전철의 차체 진동 해석 (Vibration Analysis of High-Speed EMU Car Body Using Equivalent Stiffness and Shell Element)

  • 백승국;신범식;최진환;이상원;최연선;구자춘
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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    • pp.217-222
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    • 2009
  • High-speed EMU under development vibrates more than a articulated high-speed train since power units are attached on each vehicle and railway vehicle. In this study, anisotropic equivalent stiffness of a aluminum extrusion plate were calculated to know and predict vibration characteristic of High-speed EMU under development. Eigen frequencies and modal shape of high speed train vehicle were calculated. And vibration generated was predicted at each position of vehicle when vehicle was operating.

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A CLASSIFICATION OF UNIQUELY DIFFERENT TYPES OF NUCLEAR FISSION GAS BEHAVIOR

  • HOFMAN GERARD L.;KIM YEON SOO
    • Nuclear Engineering and Technology
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    • 제37권4호
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    • pp.299-308
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    • 2005
  • The behavior of fission gas in all major types of nuclear fuel has been reviewed with an emphasis on more recently discovered aspects. It is proposed that the behavior of fission gas can be classified in a number of characteristic types that occur at a high or low operating temperature, and/or at high or low fissile burnup. The crystal structure and microstructure of the various fuels are the determinant factors in the proposed classification scheme. Three types of behavior, characterized by anisotropic $\alpha$-U, high temperature metallic $\gamma$-U, and cubic ceramics, are well-known and have been extensively studied in the literature. Less widely known are two equally typical low temperature kinds: one associated with fission induced grain refinement and the other with fission induced amorphization. Grain refinement is seen in crystalline fuel irradiated to high burnup at low temperatures, whereas breakaway swelling is observed in amorphous fuel containing sufficient excess free-volume. Amorphous fuel, however, shows stable swelling if insufficient excess free-volume is available during irradiation.

시효 열처리를 적용한 LPBF 제조된 마레이징 강의 마모 거동에 대한 이방성의 영향 (Effect of Anisotropy on the Wear Behavior of Age-Treated Maraging Steel Manufactured by LPBF)

  • 임승온;신세은
    • 한국분말재료학회지
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    • 제31권4호
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    • pp.308-317
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    • 2024
  • Maraging steel has excellent mechanical properties resulting from the formation of precipitates within the matrix through aging treatment. Maraging steel fabricated by the laser powder bed fusion (LPBF) process is suitable for applications including precise components and optimized design. The anisotropic characteristic, which depends on the stacking direction, affects the mechanical properties. This study aimed to analyze the influence of anisotropy on the wear behavior of maraging steel after aging treatment. The features of additive manufacturing tended to disappear after heat treatment. However, some residual cellular and dendrite structures were observed. In the wear tests, a high wear rate was observed on the building direction plane for all counter materials. This is believed to be because the oxides formed on the wear track positively affected the wear characteristics; meanwhile, the bead shape in the stacking direction surface was vulnerable to wear, leading to significant wear.

콜레스테릴과 아크릴로일 그룹을 지닌 하이드록시프로필 셀룰로오스들의 합성 및 특성 (Synthesis and Characteristics of Hydxoxypropyl Celluloses Containing Cholesteryl and Acryloyl Groups)

  • 김장훈;정승용;마영대
    • 폴리머
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    • 제28권1호
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    • pp.92-102
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    • 2004
  • 하이드록시프로필 셀룰로오스를 6-콜레스테릴옥시카보닐펜타노일 클로라이드와 반응시켜 에스터화도가 2.25-2.91 범위의 값을 갖는 6-콜레스테릴옥시카보닐펜톡시프로필 셀룰로오스들을 합성하였다. 또한 6-콜레스테릴옥시카보닐펜톡시프로필 셀룰로오스의 아크릴산 에스터들과 액정질서를 지닌 이들의 광가교 필름들을 합성하였다. 미가교와 가교시료들의 열방성 액정의 특성과 아세톤 중에서의 가교시료들의 팽윤거동을 검토하였다. 하이드록시프로필 셀룰로오스는 쌍방성 콜레스테릭 상을 형성하는 반면 모든 콜레스테릴을 지닌 미가교 시료들은 단방성 콜레스테릭 상을 형성하였다. 6-콜레스테릴옥시카보닐펜타노일 클로라이드는 단방성 스멕틱 상도 형성하였다. 하이드록시프로필 셀룰로오스는 광학 피치 (λ$_{m}$ )가 온도상승에 의해 증가하는 우측방향의 나선을 형성하는 반면 모든 미가교 유도체들은 λ$_{m}$ 이 온도상승에 의해 감소하는 좌측방향의 나선들을 형성하였다. 6-콜레스테릴옥시카보닐펜톡시프로필 셀룰로오스와 이의 아크릴산 에스터의 액정상의 열적 안정성과 동일한 온도에서의 λ$_{m}$ 의 크기는 에스터화도가 증가함에 따라 감소하였다. 모든 가교시료들은 6-콜레스테릴옥시카보닐펜톡시프로필 셀룰로오스의 아크릴산 에스터들과 달리 반사색깔을 나타내지 않았으며 액정질서를 지닌 가교젤의 특징적인 이방성 팽윤을 나타냈다.