• 제목/요약/키워드: Spacers

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Analysis of a Novel Self-Aligned ESD MOSFET having Reduced Hot-Carrier Effects (Hot-Carrier 현상을 줄인 새로운 구조의 자기-정렬된 ESD MOSFET의 분석)

  • 김경환;장민우;최우영
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.5
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    • pp.21-28
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    • 1999
  • A new method of making high speed self-aligned ESD (Elevated Source/Drain) MOSFET is proposed. Different from the conventional LDD (Lightly-Doped Drain) structure, the proposed ESD structure needs only one ion implantation step for the source/drain junctions, and makes it possible to modify the depth of the recessed channel by use of dry etching process. This structure alleviates hot-carrier stress by use of removable nitride sidewall spacers. Furthermore, the inverted sidewall spacers are used as a self-aligning mask to solve the self-align problem. Simulation results show that the impact ionization rate ($I_{SUB}/I_{D}$) is reduced and DIBL (Drain Induced Barrier Lowering) characteristics are improved by proper design of the structure parameters such as channel depth and sidewall spacer width. In addition, the use of removable nitride sidewall spacers also enhances hot-carrier characteristics by reducing the peak lateral electric field in the channel.

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A Comparison of the Ability of Fungal Internal Transcribed Spacers and D1/D2 Domain Regions to Accurately Identify Candida glabrata Clinical Isolates Using Sequence Analysis

  • Kang, Min-Ji;Choi, Yoon-Sung;Kim, Sunghyun
    • Biomedical Science Letters
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    • v.24 no.4
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    • pp.430-434
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    • 2018
  • Candida glabrata is the second most prevalent causative agent for candidiasis following C. albicans. The opportunistic yeast, C. glabrata, is able to cause the critical bloodstream infections in hospitalized patients. Conventional identification methods for yeasts are often time consuming and labor intensive. Therefore, recent studies on sequence-based identification have been conducted. Recently, sequencing the D1/D2 domain of the large subunit ribosomal RNA gene and the internal transcribed spacers (ITS) 1 and ITS2 regions of the ribosomal DNA has proven useful for DNA-based identification of most species of fungi. In the present study, therefore, fungal ITS and D1/D2 domain regions were targeted and analyzed by DNA sequencing for the accurate identification of C. glabrata clinical isolates. A total of 102 C. glabrata clinical isolates from various clinical samples including bloodstream, catheterized urine, bile and other body fluids were used in the study. The results of the DNA sequence analysis showed that the mean standard deviation of species identity percent score between ITS and D1/D2 domain regions was $97.8%{\pm}2.9$ and $99.7%{\pm}0.46$, respectively. These results revealed that the D1/D2 domain region might be a better target for identifying C. glabrata clinical isolates based on DNA sequences than the ITS1 and ITS2 regions. However, in order to evaluate the usefulness of D1/D2 domain region for species identification of all Candida species, other Candida species such as C. albicans, C. tropicalis, C. dubliniensis, and C. krusei should be verified in further studies additionally.

Numerical Analysis of Concentration Polarization for Spacer Configuration in Plate Type Membrane Module (평판형 분리막 모듈 내 스페이서 형태에 따른 농도분극에 관한 수치해석)

  • Shin, Ho Chul;Chung, Kun Yong
    • Applied Chemistry for Engineering
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    • v.22 no.6
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    • pp.703-710
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    • 2011
  • As the spacer in the membrane module provide the channel space to flow the feed solution smoothly and induce the flow turbulence, it could help to reduce both the concentration polarization and to take the long-term operation of membrane modules with high permeate flux by mixing the accumulated contaminants on the membrane surface into the bulk solution. In this study, the concentration distribution in membrane module with respect to the spacers which have the cross-sectional shapes of circle, cross, diamond and hexagon, the angles of spacer configuration, solute rejection and permeate flux were interpreted and optimized numerically using the "COMSOL Multiphysics" software. The concentration on the membrane surface was kept the lowest level for the cross-shape among the above four types of spacers. Also the 30 degree spacer configuration was showed as the most efficient case. The concentrations on the membrane surface at the module outlet for without spacer and the cross shape with the 30 degree spacer configuration were 2.09 and 1.29 times higher than those at inlet, respectively. The reduction effect of concentration polarization increased rapidly as the permeate flux increased.

Cu Blackening through CuO Oxidation for the Application of Camera Lens Spacers in Mobile Phones (휴대폰 카메라 렌즈 스페이서 적용을 위한 구리의 흑화)

  • Lee, Yeji;Kim, Yong Ha;Kim, Chang Hyun;Won, Yong Sun
    • Clean Technology
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    • v.27 no.1
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    • pp.17-23
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    • 2021
  • Black polymer spacers are currently used for physically separating aligned camera lenses in camera modules of mobile phones. However, the mechanical properties of polymer spacers have their limits, especially in the current trend of using more lenses in thinner camera modules. Thus, copper (Cu) becomes a good candidate for those polymer spacers because of its superior mechanical properties and its inherent blackness due to its black surfaced oxides, such as copper (II) oxide (cupric oxide, CuO). The latter property is critical in quality control because the closer the color of a spacer is to black, the less light interference and flaring phenomena can occur. A standard Cu blackening process and its operational conditions were proposed in this study through a comprehensive analysis of previous research and patents. The Cu blackening process is composed of cleaning, deoxidizing, activating, blackening and sealing. The effects of operational parameters, such as the temperature of each unit process and the activator concentration, were then investigated by measuring the blackness of the Cu strips with a colorimeter. The proposed operational conditions were determined by whether the blackness of Cu strips was within the on-spec. value used in the field.

Thermal Stability of Titanium and Cobalt Thin Films on Silicon Oxide Spacer (티타늄과 코발트 박막의 산화규소 스페이서에 대한 열적안정성)

  • Cheong, Seong-Hwee;Song, Oh-Sung;Kim, Min-Sung
    • Korean Journal of Materials Research
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    • v.12 no.11
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    • pp.865-869
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    • 2002
  • We investigated the reaction stability of titanium, cobalt and their bilayer films with side-wall spacer materials of SiO$_2$ for the salicide process. We prepared Ti 350 $\AA$, Co 150 $\AA$, Co 150 $\AA$/Ti 100 $\AA$ and Ti 100 $\AA$/Co 150 $\AA$ films on 1000 $\AA$-thick thermally grown SiO$_2$ substrates, respectively. Then the samples were rapid thermal annealed at the temperatures of $500^{\circ}C$, $600^{\circ}C$, and $700^{\circ}C$ for 20 seconds. We characterized the sheet resistance of the metallic layers with a four-point probe, surface roughness with scanning probe microscope, residual phases with an Auger depth profilometer, phase identification with a X-ray diffractometer, and cross-sectional microstructure evolution with a transmission electron microscope, respectively. We report that Ti reacted with silicon dioxide spacers above $700^{\circ}C$, Co agglomerated at $600^{\circ}C$, and Co/Ti, Ti/Co formed CoTi compound requiring a special wet process.