• 제목/요약/키워드: Proximity effect

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A Study on Pattern Fabrication using Proximity Effect Correction in E-Beam Lithography (전자빔 리소그래피에서의 근접효과 보정을 이용한 패턴 제작에 관한 연구)

  • Oh, Se-Kyu;Kim, Dong-Hwan;Kim, Seung-Jae
    • Journal of the Semiconductor & Display Technology
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    • v.8 no.2
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    • pp.1-10
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    • 2009
  • This study describes the electron beam lithography pattern fabrication using the proximity effect correction. When electron beam exposes into electron beam resist, the beam tends to spread inside the substance (forward scattering). And the electron beam reflected from substrate spreads again (back scattering). These two effects influence to distribution of the energy and give rise to a proximity effect while a small pattern is generated. In this article, an electron energy distribution is modeled using Gaussian shaped beam distribution and those parameters in the model are computed to solidify the model. The proximity effect is analyzed through simulations and appropriate corrections to reducing the proximity effect are suggested. It is found that the proximate effect can be reduced by adopting schemes of dose adjustment, and the optimal dose is determined through simulations. The proposed corrected proximity effect correction is proved by experiments.

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Proximity Effect in Nb/Gd Layers

  • Jung, Dong-Ho;Char, K.
    • Progress in Superconductivity
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    • v.12 no.2
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    • pp.110-113
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    • 2011
  • We have grown a Nb/Gd bilayer on a$SiO_2$/Si substrate by using a DC magnetron sputtering system, which was fabricated in situ with silicon stencil masks. In order to investigate proximity effect of the Nb/Gd bilayer, we used a planar tunnel junction with an AlOx tunnel barrier by oxidizing the Al ground electrode at the bottom. A $Co_{60}Fe_{40}$ backing of Al was deposited so as to reduce the superconductivity of the Al, ensuring a normal counterelectrode. With a 50-nm-thick Nb layer, we have measured dI/dV (dynamic conductance) by varying the thickness of Gd, which can reveal the density of states (DOS) of the Nb/Gd bilayer as a function of the Gd thickness resulting from the proximity effect of a superconductor/ferromagnet bilayer (S/F). The SF proximity effect in Nb/Gd will be discussed in comparison to our previous results of the CoFe/Nb, Ni/Nb and CuNi/Nb proximity effect; Gd is expected to show different effects since Gd has f-electrons, while CoFe, Ni, and CuNi have only d-electrons. Our studies will focus on the triplet correlation in a superconducting pair.

전압안정도 개선을 위한 무효전력 제어

  • Kim, Geon-Jung;Kim, Won-Gyeom;Jeong, Tae-Ho;Lee, Sang-Jung
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.422-425
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    • 1991
  • This paper presents the effect of the voltage proximity index for the voltage collpase in power systems. The reactive generation limits are considered for the determination of the voltage proximity index. This paper also shows how the VAR investment ranking order works by the sensitivity index(proximity index). Simulation has carried out with the IEEE 14 bus system and has shown the voltage proximity index working well.

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A Layout-Based CMOS RF Model for RFIC's

  • Park Kwang Min
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.3
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    • pp.5-9
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    • 2003
  • In this paper, a layout-based CMOS RF model for RFIC's including the capacitance effect, the skin effect, and the proximity effect between metal lines on the Si surface is proposed for the first time for accurately predicting the RF behavior of CMOS devices. With these RF effects, the RF equivalent circuit model based on the layout of the multi-finger gate transistor is presented. The capacitances between metal lines on the Si surface are modeled with the layout. And the skin effect is modeled to the equivalent ladder circuit of metal line. The proximity effect is modeled by adding the mutual inductance between cross-coupled inductances in the ladder circuit representation. Compared to the BSIM 3v3 and other models, the proposed RF model shows better agreements with the measured data and shows well the frequency dependent behavior of devices in GHz ranges.

Network, Channel, and Geographical Proximity of Knowledge Transfer: The Case of University-Industry Collaboration in South Korea

  • Kwon, Ki-Seok;Jang, Duckhee;Park, Han Woo
    • Asian Journal of Innovation and Policy
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    • v.4 no.2
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    • pp.242-262
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    • 2015
  • The relationship between geographical proximity and academics' formal and informal knowledge-transfer activities in the network is analyzed with a mixed research method. With social network analysis as a basis, we have explored the networks between academics and firms in the 16 regions of South Korea. The result shows Seoul and Gyunggi are identified as central nodes, meaning that the academics in other regions tend to collaborate with firms in these regions. An econometric analysis is performed to confirm the localization of knowledge-transfer activities. The intensity of formal channels measured by the number of academic papers is negatively, but significantly associated with the geographical proximity. However, we have not found any significant relationship between the formality of the channels and geographical proximity. Possibly, the regional innovation systems in South Korea are neither big enough nor strong enough to show a localization effect.

EFFECT OF WALL PROXIMITY ON DRAG AND LIFT FORCES ON A CIRCULAR CYLINDER (벽 근접 효과에 의한 물체의 항력 양력 변화)

  • Park, Hyun-Wook;Lee, Chang-Hoon;Choi, Jung-Il
    • Journal of computational fluids engineering
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    • v.17 no.3
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    • pp.68-74
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    • 2012
  • Near-wall effect on wakes behind particles is one of the important factors in precise tracking of particles in turbulent flows. However, most aerodynamic force models for particles did not fully consider the wall effect. In the present study, we focused on changes of hydrodynamic forces acting on a particle depending on wall proximity. To this end, we developed an immersed boundary method with multi-direct forcing incorporated to a fully implicit decoupling procedure for incompressible flows. We validate the present immersed boundary method through two-dimensional simulations of flow over a circular cylinder. Comprehensive parametric studies on the effect of the wall proximity on the drag and lift forces acting on an immersed circular cylinder in a channel flow are performed in order to investigate general flow patterns behind the circular cylinder for a wide range of Reynolds number (0.01 ${\leq}$ Re ${\leq}$ 200). As the cylinder is closer to the wall, the drag coefficient decreases while the lift coefficient increases with a local maximum. Maximum drag and lift coefficients for different wall proximities decrease with increment of Reynolds number. Normalized drag and lift coefficients by their maximum values show universal correlations between the coefficients and wall proximity in a low Reynolds number regime (Re ${\leq}$ 1).

Growth and properties of LCMO/YBCO heterostructure

  • Kumar, Manish;Lee, Hyun Hwi
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.151.1-151.1
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    • 2016
  • Complex oxide heterointerfaces have been extensively explored in the past due to the novel phenomenon emerging at such interfaces that differ from their individual bulk counterparts. The integration of a ferromagnetic (FM) material with the superconducting (SC) material leading to proximity effect is one of the commonly studied phenomenon in these heterostructures. In continuation, we have stabilized the FM layer La0.7Ca0.3MnO3 (LCMO) on SC material YBa2Cu3O7-${\delta}$ (YBCO) using pulsed laser deposition technique and explored the structural, magnetic, electrical and magneto-transport properties of this heterostructure. ${\Phi}$-scan measurements confirm the epitaxial nature of LCMO/YBCO heterostructure grown on single crystalline SrTiO3 substrate. The FM transition of LCMO and SC transition of YBCO are observed in the magnetization measurements of the bilayer structure. Through electrical measurements, we understood that the proximity effect leads to lowering of the SC transition of YBCO. The role of interface in the bilayer structure is also realized through electrical transport measurements.

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The Role of CSR Proximity and Psychological Distance as a Marketing Strategy

  • Kim, Dong-Tae;Kim, Moon-Seop;Ahn, Sung-Sook
    • Journal of Distribution Science
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    • v.15 no.9
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    • pp.75-83
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    • 2017
  • Purpose - This study aims to find ways to have CSR efforts lead to a purchase decision. For this purpose, this research examines the influence of the perceived CSR proximity on the purchase intention and studies the moderating role of psychological distance. Research design, data, and methodology - A total of 185 undergraduate students from a university in Korea were recruited and were randomly assigned to the conditions of a 2 (CSR proximity: close vs. far) × 2 (temporal distance: near vs. distant) × 2 (information type: concrete vs. abstract) between-subjects design. ANOVA was conducted to test the hypotheses. Results - When consumers construe a purchase decision at a high level via the far psychological distance, a firm's CSR efforts are considered important for the purchase decision. Conversely, when consumers construe a purchase decision at a low level via the near psychological distance, a firm's CSR efforts are not considered for the purchase decision. Conclusions - This research demonstrates that people have a greater intention to purchase products from a firm whose CSR proximity is perceived as being close rather than far. Furthermore, this study shows that the psychological distance moderates the effect of CSR proximity on the purchase intention.