• Title/Summary/Keyword: trenches

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Reduction of Railway-induced Vibration using In-filled Trenches with Pipes

  • Hasheminezhad, Araz
    • International Journal of Railway
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    • v.7 no.1
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    • pp.16-23
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    • 2014
  • Reduction in railway-induced vibrations in urban areas is a very challenging task in railway transportation. Many mitigation measures can be considered and applied. Among these, a little attention has been paid to trenches. In this study, a numerical investigation on the effectiveness of in-filled trenches with pipes in reducing railway vibrations due to passing trains is presented. Particularly, a series of two-dimensional dynamic analysis was performed to model the behavior of ballasted railway track under harmonic load with ABAQUS software as a Finite Element method. In so doing, two types of in-filled trenches with pipes with steel and concrete materials have been investigated in this paper. In addition, effectiveness of pipes made of steel and concrete, filled with loose sand and clay in railway-induced vibration reduction has been assessed. The results point out that using in-filled trench with pipes does not effective a lot on railway-induced vibration reduction in comparison to other railway-induced vibration reduction methods. However, in-filled trenches with steel pipes are much more effective than in-filled trenches with concrete pipes. Moreover, filling pipes with loose sand and clay does not have any effect on vibration reduction efficiency of these in-filled trenches.

Fabrication of embedded bottom electrodes for submicron beam resonators (서브마이크론 빔 레조네이터 제작을 위한 바닥전극 형성방법)

  • Lee, Yong-Seok;Jang, Yun-Ho;Bang, Yong-Seung;Kim, Jung-Mu;Kim, Jong-Man;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 2008.10a
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    • pp.131-132
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    • 2008
  • We describe a fabrication method of submicron glass trenches which have embedded metal lines for the future application of nano-scale RF MEMS devices. The glass wafer was etched using two different conditions to identify the relationship between the slope of glass trenches and the slope of photroresist. A self-aligned metal photomask and negative photroresist (PR) slope were used to insert metal lines inside the glass trenches. The PR slope patterned by backside photolithography was affected by the profile of preformed glass trenches. Gold was well fabricated in the $0.7{\mu}m$ wide trench thanks to the negative PR slope. Nano-scale glass trenches with embedded metal lines can be used as a bottom electrode in submicron beam resonators operating with a high resonant frequency.

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Design and analysis of a mode size converter composed of periodically segmented taper waveguide surrounded by trenches (좌우 트렌치를 구비한 분리 주기 테이퍼 도파로 모드 크기 변환기의 설계 및 성능 분석)

  • Park Bo Gen;Chung Young Chul
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.12
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    • pp.43-49
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    • 2004
  • In this paper, we have designed a mode size converter to reduce coupling loss between super-high delta silica optical waveguides and single mode fibers. The new mode size converter has three design aspects; periodically segmented taper waveguide for minimal size, lateral taper waveguide for simple fabrication, and surrounding trenches to improve coupling loss. In the optimal mode size converter design, coupling loss is 0.33dB/point without trenches and 0.2dB/point with trenches.

The Fabrication Processes for the Planarization of Sacrificial Layers over Hollow Structures (Hollow Structure에서의 희생층 평탄화 제작 공정)

  • Yoon Yong-Seop;Bae Ki-Deok;Choi Hyung;Jun Chan-Bong;Ro Kwang-Choon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.10
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    • pp.546-550
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    • 2004
  • Two fabrication approaches are proposed to planarize the sacrificial layer over hollow structures. One is the photoresist filling method that makes use of photolithography, thermal curing and plasma ashing. The other is the lamination method that is applying pressure and temperature to the organic film over the hollow structures. The fabrication results are compared with those of CMP process. Trenches and cavities with various dimensions have been made for the porposed process. Upon measuring the planarization levels, they are dependent on planarization methods and the geometrical size of hollow structures. The photoresist filling method is so strongly dependent on the width and depth of trenches that we have problems to use it for large dimensional trenches. To the contrary, the flatness of sacrificial layer over the trenches was found to be almost independent of trench dimensions for the lamination method. A CMP process shows the most excellent results, but the fabrication is complicated and the access to it is not so easy. It is important to choose the proper planarization method by considering the required flatness levels, materials to be planarized, and connection between the planarization step and the previous or the following process of it.

Effect of Surface Roughness on the Formation of Micro-Patterns by Soft Lithography (표면 평탄도가 소프트리소법에 의한 미세 패턴 형성에 미치는 영향)

  • Kim, Kyung Ho;Choi, Kyun;Han, Yoonsoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.12
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    • pp.871-876
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    • 2014
  • Efficiency of crystalline Si solar cell can be maximized as minimizing optical loss through antireflection texturing with inverted pyramids. Even if cost-competitive, soft lithography can be employed instead of photolithography for the purpose, some limitations still remain to apply the soft lithography directly to as-received solar grade wafer with a bunch of micro trenches on surface. Therefore, it is needed to develop a low-cost, effective planarization process and evaluate its output to be applicable to patterning process with PDMS stamp. In this study new surface planarization process is proposed and the change of micro scale trenches on the surface as a function of etching time is observed. Also, the effect of trenches on pattern quality by soft lithography is investigated using FEM structural analysis. In conclusion it is clear that the geometry and shape of trenches would be basic considerations for soft lithography application to low quality wafer.

The Fabrication of Micro-heaters with Low Consumption Power Using SOI and Trench Structures and Its Characteristics (SOI와 트랜치 구조를 이용한 초저소비전력형 미세발열체의 제작과 그 특성)

  • 정귀상;홍석우;이원재;송재성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.3
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    • pp.228-233
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    • 2001
  • This paper presents the optimized design, fabrication and thermal characteristics of micro-heaters for thermal MEMS (micro elelctro mechanical system) applications usign SOI (Si-on-insulator) and trench structures. The micro-heater is based on a thermal measurement principle and contains for thermal isolation regions a 10㎛ thick Si membrane with oxide-filled trenches in the SOI membrane rim. The micro-heater was fabricated with Pt-RTD (resistance thermometer device) on the same substrate by suing MgO as medium layer. The thermal characteristics of the micro-heater wit the SOI membrane is 280$\^{C}$ at input power 0.9W; for the SOI membrane with 10 trenches, it is 580$\^{C}$ due to reduction of the external thermal loss. Therefore, the micro-heater with trenches in SOI membrane rim provides a powerful and versatile alternative technology for improving the performance of micro-thermal sensors and actuators.

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A Study of Isolation-Effect of Surface Wave Using Open or In-filled Trenches (진동차단 구조물에 의한 표면파의 진동차단효과에 관한 연구)

  • 김문겸
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.04a
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    • pp.100-108
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    • 1999
  • rectangular open or in-filled trenches(concrete and rubber) are often used to reduce the ground vibrations caused by propagating surface(Rayleigh) waves. This paper presents the experimental data for estimating the vibration screening effectiveness of open or in-filled trenches Field dynamic tests using the exciter which can generate the 100kN vertical cyclic load in the range of 100-250 Hz were performed. One hundred and twenty accelerometers to measure the ground response are used in 6 radial direction. To compare the effectiveness of the vibration isolation the contours of the amplitude ratio with the dimensionless parameters dividing by Rayleight wave lengths were presented.

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The fabrication of ultra-low consumption power type micro-heaters using SOI and trenche structures (SOI와 드랜치 구조를 이용한 초저소비전력형 미세발열체의 제작)

  • 정귀상;이종춘;김길중
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.569-572
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    • 2000
  • This paper presents the optimized fabrication and thermal characteristics of micro-heaters for thermal MEMS applications using a SDB SOI substrate. The micro-heater is based on a thermal measurement principle and contains for thermal isolation regions a 10$\mu\textrm{m}$ thick silicon membrane with oxide-filled trenches in the SOI membrane rim. The micro-heater was fabricated with Pt-RTD(Resistance Thermometer Device)on the same substrate by using MgO as medium layer. The thermal characteristics of the micro-heater with the SOI membrane is 280$^{\circ}C$ at input Power 0.9 W; for the SOI membrane with 10 trenches, it is 580$^{\circ}C$ due to reduction of the external thermal loss. Therefore, the micro-heater with trenches in SOI membrane rim provides a powerful and versatile alternative technology for improving the performance of micro thermal sensors and actuators.

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The effect of plamsa treatment on superconformal copper gap-fill

  • Mun, Hak-Gi;Kim, Seon-Il;Park, Yeong-Rok;Lee, Nae-Eung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.249-249
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    • 2010
  • The effect of forming a passivation layer was investigated in superconformal Cu gap-filling of the nano-scale trench with atomic-layer deposited (ALD)-Ru glue layer. It was discovered that the nucleation and growth of Cu during metal-organic chemical vapor deposition (MOCVD) were affected by hydrogen plasma treatments. Specifically, as the plasma pretreatment time increased, Cu nucleation was suppressed proportionally. XPS and Thermal Desorption Spectroscopy indicated that hydrogen atoms passivate the Ru surface, which leads to suppression of Cu nucleation owing to prevention of adsorption of Cu precursor molecules. For gap-fill property, sub 60-nm ALD Ru trenches without the plasma pretreatment was blocked by overgrown Cu after the Cu deposition. With the plasma pretreatment, superconformal gap filling of the nano-scale trenches was achieved due to the suppression of Cu nucleation near the entrances of the trenches. Even the plasma pretreatment with bottom bias leads to the superconformal gap-filling.

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Effects of Leveler on the Trench Filling during Damascene Copper Plating (전해전착시 상감 구리 배선의 충전에 미치는 레벨러의 효과)

  • Lee, Yu-Young;Park, Young-Joon;Lee, Jae-Bong;Cho, Byung-Won
    • Journal of the Korean Electrochemical Society
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    • v.5 no.3
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    • pp.153-158
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    • 2002
  • The effects of leveler on the copper trench filling were investigated during damascene plating process. To investigate the trench filling effect with the addition of a leveler, a cross-section images of the electroplated trenches with the width of$0.37{\mu}m,\;and\;0.18{\mu}m$ were observed by field emission scanning electron microscope (FE-SEM). Polyethylene glycol(PEG), 3-mercapto-1-propanesulfonic acid and Janus Green B were used as a carrier, an accelerator and a leveler. $0.37{\mu}m$ trenches were superfilled without voids, but there was voids formation in $0.18{\mu}m$ trenches when the leveler was not added into the electrolyte. On the other hand $0.18{\mu}m$ trenches were superfilled without voids with the addition of the leveler due to the reduction growth rate of copper at protrusions and edges, which yield smooth final deposit surface. The leverer effect becomes more significant as the width of trenches becomes smaller when trenches are filed.