• Title/Summary/Keyword: Enhanced layer

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A Study on the Corrosion Resistance of Free Cutting Steels after Oxy-Nitriding (진공산질화기술에 의한 쾌삭강의 내부식성 향상기술)

  • Moon, Kyoung Il;Kim, Sang Gweon;Kim, Sung Wan
    • Journal of the Korean Society for Heat Treatment
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    • v.19 no.2
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    • pp.90-95
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    • 2006
  • Nitriding or carburizing of carbon steels results in good mechanical properties such as high surface hardness and wear resistance but it has no affection on the corrosion resistance. Corrosion properties of nitriding and carburizing steels could be deteriorated. So, recently, there have been great demand for oxi-nitriding to enhance both mechanical properties and corrosion resistance. In this study, the corrosion resistance of carbon steel, S35C, and free cutting steel, SUM222, are prepared by vacuum nitriding and vacuum post-oxidation were compared with those treated by nitriding. After vacuum post-oxidation, $5{\mu}m$ oxide layer was formed on the nitride layer with $20{\sim}30{\mu}m$ depth. Potentio-dynamic polarization curve in corrosion test showed that the corrosion potential after post oxidation was increased from 200 mV to 800 mV in S35C and from 600 mV to 1200 mV in SUM222. SEM analyses showed that pores was increased and surface roughness became rougher with post oxidation. However, the formation of $Fe_3O_4$ resulted in the enhanced corrosion resistance of steels.

A Study on Adhesion and Electro-optical Properties of ITO Films Deposited on Flexible PET Substrates with Deposition of SiO2 Buffer Layers (PET 기판 위에 SiO2 버퍼층 증착에 따른 ITO 박막의 부착 및 전기적 광학적 특성 연구)

  • Kang, Ja-Youn;Kim, Dong-Won;Cho, Kyu-Il;Woo, Byung-Il;Yun, Hwan-Jun
    • Journal of the Korean institute of surface engineering
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    • v.42 no.1
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    • pp.21-25
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    • 2009
  • Using an evaporation system, $SiO_2$ was deposited as a buffer layer between a PET substrate and a ITO layer and then ITO/$SiO_2$/PET layers were annealed for 1.5 hours at the temperature of $180^{\circ}C$. Adhesion and electro-optical properties of ITO films were studied with thickness variance of a $SiO_2$ buffer layer. As a result of introduction of the $SiO_2$ buffer layer, sheet resistance and resistivity increased and a ITO film with optimum sheet resistance ($529.3{\Omega}/square$) for an upper ITO film of resistive type touch panel could be obtained when $SiO_2$ of $50{\AA}$ was deposited. And it was found that ITO films with $SiO_2$ buffer layer have higher transmittance of $88{\sim}90%$ at 550 nm wavelength than ITO films with no buffer layers and the transmittance was enhanced as $SiO_2$ thickness increased from $50{\AA}$ to $100{\AA}$. Adhesion property of ITO films with $SiO_2$ buffer layers became better than ITO films with no buffer layers and this property was independent of $SiO_2$ thickness variance ($50{\sim}100{\AA}$). By depositing a $SiO_2$ buffer layer of $50{\AA}$ on the PET substrate and sputtering a ITO thin film on the layer, a ITO film with enhanced adhesion, electro-optical properties could be obtained.

Fabrication and Characterization of an Antistiction Layer by PECVD (plasma enhanced chemical vapor deposition) for Metal Stamps (PECVD를 이용한 금속 스탬프용 점착방지막 형성과 특성 평가)

  • Cha, Nam-Goo;Park, Chang-Hwa;Cho, Min-Soo;Kim, Kyu-Chae;Park, Jin-Goo;Jeong, Jun-Ho;Lee, Eung-Sug
    • Korean Journal of Materials Research
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    • v.16 no.4
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    • pp.225-230
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    • 2006
  • Nanoimprint lithography (NIL) is a novel method of fabricating nanometer scale patterns. It is a simple process with low cost, high throughput and resolution. NIL creates patterns by mechanical deformation of an imprint resist and physical contact process. The imprint resist is typically a monomer or polymer formulation that is cured by heat or UV light during the imprinting process. Stiction between the resist and the stamp is resulted from this physical contact process. Stiction issue is more important in the stamps including narrow pattern size and wide area. Therefore, the antistiction layer coating is very effective to prevent this problem and ensure successful NIL. In this paper, an antistiction layer was deposited and characterized by PECVD (plasma enhanced chemical vapor deposition) method for metal stamps. Deposition rates of an antistiction layer on Si and Ni substrates were in proportion to deposited time and 3.4 nm/min and 2.5 nm/min, respectively. A 50 nm thick antistiction layer showed 90% relative transmittance at 365 nm wavelength. Contact angle result showed good hydrophobicity over 105 degree. $CF_2$ and $CF_3$ peaks were founded in ATR-FTIR analysis. The thicknesses and the contact angle of a 50 nm thick antistiction film were slightly changed during chemical resistance test using acetone and sulfuric acid. To evaluate the deposited antistiction layer, a 50 nm thick film was coated on a stainless steel stamp made by wet etching process. A PMMA substrate was successfully imprinting without pattern degradations by the stainless steel stamp with an antistiction layer. The test result shows that antistiction layer coating is very effective for NIL.

Low temperature growth of carbon nanotube by plasma enhanced chemical vapor deposition (PECVD) using nickel catalyst

  • Ryu, Kyoung-Min;Kang, Mih-Yun;Kim, Yang-Do;Hyeongtag-Jeon
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2000.04a
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    • pp.109-109
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    • 2000
  • Recently, carbon nanotube has been investigating for field emission display ( (FED) applications due to its high electron emission at relatively low electric field. However, the growing of carbon nanotube generally requires relatively high temperature processing such as arc-discharge (5,000 ~ $20,000^{\circ}C$) and laser evaporation (4,000 ~ $5,000^{\circ}C$) methods. In this presentation, low temperature growing of carbon nanotube by plasma enhanced chemical vapor deposition (PECVD) using nickel catalyst which is compatible to conventional FED processing temperature will be described. Carbon n notubes with average length of 100 run and diameter of 2 ~ $3\mu$ill were successfully grown on silicon substrate with native oxide layer at $550^{\circ}C$using nickel catalyst. The morphology and microstructure of carbon nanotube was highly depended on the processing temperature and nickel layer thickness. No significant carbon nanotube growing was observed with samples deposited on silicon substrates without native oxide layer. This is believed due to the formation of nickel-silicide and this deteriorated the catalytic role of nickel. The formation of nickel-silicide was confirmed by x-ray analysis. The role of native oxide layer and processing parameter dependence on microstructure of low temperature grown carbon nanotube, characterized by SEM, TEM XRD and R없nan spectroscopy, will be presented.

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PEALD과 ALD을 이용한 다공성 기판의 증착 특성 비교

  • Gang, Go-Ru;Cha, Deok-Jun;Kim, Jin-Tae;Yun, Ju-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.155.2-155.2
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    • 2014
  • Plasma Enhanced Atomic Layer Deposition(PEALD)와 Atomic Layer Deposition(ALD) Techniques는 '정확한 두께 조절' 및 '우수한 균일도'를 가지는 신뢰할 수 있는 진공 기술이다. 본 연구에서는 다공성 구조를 가지는 기판을 대상으로 PEALD와 ALD Techniques을 이용한 $Al_2O_3$ 형성 공정의 증착 특성을 비교하였다. 각 공정은 공통적으로 Tris-Methyl-Aluminium(TMA)을 첫번째 전구체로 사용하였고 purge gas로는 Nitrogen를 사용하였다. 그리고 두번째 전구체로 PEALD 공정에서는 Oxygen Plasma를 사용하였고 ALD 공정에서는 Water를 사용하였다. 복잡한 다공성 구조를 가지는 기판은 $TiO_2$ Nano-Particle paste과 colloidal Silver paste를 소결시켜 제작하여 사용하였다. 각 공정의 차이점을 비교하기 위해서 배기단에 Capacitor Diaphram Gauge(CDG)와 Residual Gas Analyzer(RGA)를 통해서 압력과 잔류 가스를 모니터하였다. 그리고 각 공정을 통해서 porous한 Nano-Particles Network에 형성된 $Al_2O_3$막의 특성을 비교하기 위해서 FE-SEM과 EDX를 통해서 관찰하였다. 또한 좀 더 자세한 비교 분석을 위해서 $Al_2O_3$ 막이 형성된 porous한 Nano-Particles Networks의 각 각의 particles들을 분산시켜 TEM과 AFM를 통해서 관찰하였다. 나아가 전기적 물성의 차이점을 비교하기 위해서 IV 및 CV를 측정하였다. 위의 일련의 비교 실험을 통해서 'PEALD과 ALD을 이용한 다공성 기판의 증착 특성'에 대하여 고찰하였다.

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Enhanced Stability of Organic Photovoltaics by Additional ZnO Layers on Rippled ZnO Electron-collecting Layer using Atomic Layer Deposition

  • Kim, Kwang-Dae;Lim, Dong Chan;Jeong, Myung-Geun;Seo, Hyun Ook;Seo, Bo Yeol;Lee, Joo Yul;Song, Youngsup;Cho, Shinuk;Lim, Jae-Hong;Kim, Young Dok
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.353-356
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    • 2014
  • We fabricated organic photovoltaic (OPV) based on ZnO ripple structure on indium tin oxide as electron-collecting layers and PTB7-F20 as donor polymer. In addition, atomic layer deposition (ALD) was used for preparing additional ZnO layers on rippled ZnO. Addition of 2 nm-thick ALD-ZnO resulted in enhanced initial OPV performance and stability. Based on photoluminescence results, we suggest that ALD-ZnO layers reduced number of surface defect sites on ZnO, which can act as electron-hole recombination center of OPV, and increased resistance of ZnO towards surface defect formation.

The Enhanced Electrochemical Performance of Lithium Metal Batteries through the Piezoelectric Protective Layer (압전 특성의 보호층을 통한 리튬 금속 전지의 전기화학적 특성 개선)

  • Dae Ung Park;Weon Ho Shin;Hiesang Sohn
    • Membrane Journal
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    • v.33 no.1
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    • pp.13-22
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    • 2023
  • Despite high capacity of lithium metal anode, its uncontrollable dendrite growth results in the poor electrochemical (EC) performance (low Coulomb efficiency and limited cycle stability) and unsafe operation. In this study, we demonstrated a lithium metal anode protected with BaTiO3/PVDF based piezoelectric layer to enhance its EC performance by utilizing the locally polarized lithium metal after volume expansions. As-formed lithium metal electrode deposited with BTO@PVDF layer exhibited an enhanced Coulombic efficiency (> 98% for 100 cycles) and facilitated lithium ion diffusions (lithium diffusion coefficient: DLi+), revealing the effectiveness of piezoelectric layer deposited lithium metal electrode approach.

Nanocomposite Cover-layer for NFR Media (Nanocomposite 이용한 NFR Media 커버층 특성연구)

  • Kim, Jin-Hong;Lee, Jun-Seok;Seo, Jeong-Kyo
    • Transactions of the Society of Information Storage Systems
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    • v.3 no.1
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    • pp.17-22
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    • 2007
  • [ $TiO_2$ ] nanoparticles are added into UV curable resin to increase the refractive index of the cover-layer which is laminated on the media for cover-layer incident NFR. High refractive index is required for the cover-layer operating for the solid immersion lens optics with high effective numerical aperture. The eyepattern could be achieved from the cover-layer coated 20 GB ROM disc in which the refractive index of the cover-layer was 1.75, but the gap servo was unstable due to the rough surface of the cover-layer. Even though the light loss due to the nanoparticles is not serious, the rough microstructure is developed by adding the nanoparticles in the organic binder material. To achieve smooth surface for the stable gap servo, some special techniques should be added, for example the solubility of the nanoparticles should be enhanced by the optimization of the surface of the nanoparticles.

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