• 한국표면공학회지
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• 제30권4호
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• pp.262-271
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• 1997

Nickel-matal hydride(Ni-MH) batteries are receiving attention as non-pollunting. high performance rehargeable energy stoage system. The performance of Ni-Mh is significantly influenced by the hydrogen storage alloy materiels used as an anode material. Recently, having discharge capacities higher than the $AB_5$-type hydrogen storage alloys, the Zr-based $AB_2$-Type hydrogen storage alloys has remaining problems regarding cycle life and self-dischareg. These problems need to be solved by improvements in the alloy design and/or surface treatment. This work investiggates the effects the effects of surface property by fluorination on $Zr_{0.7}Ti_{0.3}V_{0.4}Mn_{0.4}Ni{1.2}$ composittion $AB_2$-Type hydrogen storage alloys. EPMA, SEM and AES techniques were used for surface analysis, and the crystal structure was characterized by constant current cycling test and potential sweep methods. Fluorination was found to be effective when La-was incorporated into the alloy, and has unique morphology, higher reactivity, and at the same time formed a protective film. Through, fluorination, the cycle life of an electrode was found to increase significantly, charge/discharge characteristics of the electrode the potential difference between the charge/discharge plateau, i.e polarization(overpotential)were improved.

• 한국표면공학회지
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• 제44권4호
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• pp.165-171
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• 2011

In this work, handling of sapphire substrate for LED by using an electrostatic chuck was studied. The electrostatic chuck consisted of alumina dielectric, which was doped with 1.2 wt% $TiO_2$. As the volume resistivity of alumina dielectric was decreased, the electrostatic force was increased by Johnsen-Rahbek effect. The narrower width and gap size of electrode led to the stronger electrostatic force. When alumina dielectric with $3.20{\times}10^{11}{\Omega}{\cdot}cm$ resistivity and 3 mm width/1.5 mm gap sized electrode was used, the strongest electrostatic force in this work was obtained, which value reached to ~14.46 gf/$cm^2$ at 2.5 kV for 4-inch sapphire substrate. This results show that alumina electrostatic chuck with low resistivity and fine electrode pattern is suitable for handling of sapphire substrate for LED.

• 한국전기전자재료학회논문지
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• 제14권4호
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• pp.281-288
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• 2001

PZT thin films (3500$\AA$) have been prepard on the Ru/Ru $O_2$ and Ru $O_2$ bottom electrodes with a RF magnetron sputtering system using P $b_{1.05}$(Z $r_{0.52}$, $Ti_{0.48}$) $O_3$ ceramic target. Ru/Ru $O_2$ bottom electrode was fabricated by in-situ processing controlled the $O_2$ partial pressure. The PZT thin films deposited on the Ru/Ru $O_2$ bottom electrode were preferred oriented (101) plane. The PZT thin films deposited on the Ru/Ru $O_2$ bottom electrodes showed better electrical properties than those with Ru $O_2$ bottom electrodes because Ru $O_2$ prevented oxygen vacancies and impurities from existing withing the interface and substrate.e.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.66-68
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• 1994

강유전체 박막과 마이크로 가공기술을 이용하여 초전형 적외선 센서를 제작하였다. 초전형 적외선 센서는 $Pb_{1-x}La_xTi_{1-x/4}O_3$ (x=0.05) (PLT) 강유전체 박막 커패시터를 RF 마그네트론 스퍼터링 방식으로 백금 전극이 증착된 MgO 기판상에 결정 성장시킨 구조를 갖고 있다. 스퍼터링된 PLT 바닥은 높은 c-축 결정 구조를 가지므로 센서로 사용하기 위한 poling 처리 과정이 필요하다. 이는 적외선 이미지 센서를 구현함에 있어서 수율 향상에 필수적인 요소이다. 마이크로 가공 기술을 사용하여 센서의 열용량을 극소화 함으로서 센서의 효율을 최대화하였다. 제작된 센서의 상부에 폴리이미드를 코팅하고 MgO 기판을 선택적으로 식각하여 코팅된 폴리이미드가 강유전체 박막 커패시터를 지지하고 있는 구조를 구현하였다. 이렇게 제작된 센서의 감도는 상온에서 $8.5{\times}10^8cm{\cdot}{\sqrt}{Hz/W}$로 측정되었으며 이는 마이크로 가공 기술을 사공하지 않은 경우보다 약 100 때의 감도 향상을 가져왔다.

• 한국세라믹학회지
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• 제37권3호
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• pp.233-239
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• 2000

Sr0.9Bi2+xTa2O9(x=0, 0.1, 0.2, 0.3) thin films on IrO2/SiO2/Si or Pt/Ti/SiO2/Si substrate were prepared by spin coating method using SBT stock solutions synthesized by MOD process. SBT thin films on IrO2 transformed to layered perovskite phase at $700^{\circ}C$, but showed low breakdown voltage due to their porous microstructure. The smaple of Sr0.9Bi2+xTa2O9 composition showed the best dielectric and electrical properties. When the sample of the same composition was annealed at 80$0^{\circ}C$, the dielectric and electric properties were improved due to the grian growth and dense surface. the remanent polarization values(2Pr) at $\pm$3 V for IrO2 and Pt electrodes were 10.5, 7.15$\mu$C/$\textrm{cm}^2$, respectively. The SBT thin film with IrO2 electrode showed the lower coercive field. The leakage current density and breakdown voltage of SBT thin films on IrO2 were higher than those on Pt.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권12호
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• pp.553-558
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• 2003

The A S $r_{0.7}$B $i_{2.6}$T $a_2$ $O_{9}$ (SBT)thin films are deposited on Pt-coated electrode(Pt/$TiO_2$/$SiO_2$/Si) using a RF magnetron sputtering method. The electrical properties of SBT capacitors with top electrodes were studied. In the XRD pattern, the SBT thin films in all annealing temperatures had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized at 75$0^{\circ}C$ and grains largely grew in oxygen annealing atmosphere. The electrical properties of SBT capacitor with top electrodes represent a favorable properties in Pt electrode. The maximum remanent polarization and the coercive electric field with Pt electrode are 12.40C/$\textrm{cm}^2$ and 30kV/cm, respectively. The dielectric constant and leakage current density with Pt electrode is 340 and 6.8110$^{-10}$ A/$\textrm{cm}^2$, respectively.y.y.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.394-397
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• 2001

In this paper, in-situ deposited Ru/RuO$_2$ bottom electrodes have been investigated as new bottom electrodes for PZT thin film capacitor application. As a comparison, structural and electrical properties of PZT thin films on Pt/Ti and RuO$_2$ bottom electrodes are also investigated. The use of Ru/RuO$_2$ hybrid electrodes showed better electrical properties in compression with RuO$_2$ bottom electrode. With increasing Ru electrode thickness, the PZT thin films showed preferred orientation along the (110) direction and leakage current of PZT thin films were improved. The PZT thin films on Ru (100nm)/RuO$_2$ electrodes exhibited excellent ferroelectric properties such as remant polarization and coercive field of 7.2 C/$\textrm{cm}^2$ and 46.35 kV/cm, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1499-1501
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• 2003

The A $Sr_{0.7}Bi_{2.6}Ta_2O_9$(SBT)thin films are deposited on Pt-coated electrode(Pt/$TiO_2/SiO_2$/Si) using RF magnetron sputtering method. The electrical properties of SBT capacitors with top electrodes were studied. In the XRD pattern, the SBT thin films in all annealing temperatures had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized at $750^{\circ}C$ and grains largely grew in oxygen annealing atmosphere. The electrical properties of SBT capacitor with top electrodes represents a favorable properties in Pt electrode. The maxim urn remanent polarization and the coercive electric field with Pt electrode are $12.40C/cm^2$and 30kV/cm respectively. The dielectric constant and leakage current density with Pt electrode is 340 and $6.8110^{-10}A/cm^2$ respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.202-203
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• 2007

Ferroelectric SBT($SrBi_2Ta_2O_9$) thin films were deposited on Pt/Ti/$SiO_2$/Si substrate using R.F. magnetron sputtering method. The ferroelectric and electric characteristics were investigated with various post-annealing of Pt at $200{\sim}600^{\circ}C$. Compared with SBT thin film which had not post-annealed, the electrical properties and crystallizations of the SBT thin films were relatively improved by the post-annealing of Pt bottom electrode. The crystallization were characterized by X-ray diffraction (XRD). The electrical properties characteristics were observed by HP 4192A and precision LC.

• 한국전기전자재료학회논문지
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• 제26권3호
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• pp.209-215
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• 2013

DSSCs electrical characteristics and efficiency fabricated with different tape casting thickness Pt counter electrodes and different thickness between $TiO_2$ photo electrode and Pt counter electrode substrate were studied. 1 layer Pt counter electrode shows 3.979% efficiency. Efficiency increased as tape casting thickness decreased. The lowest open-circuit voltage was a 0.726 V and the highest short-circuit current was a 2.188 mA on 1 layer Pt counter electrode. On the different thickness between two substrates, the lowest open-circuit voltage 0.712 V and the highest short-circuit current 2.787 mA was measured at $60{\mu}m$ surlyn film thickness and it shows the highest value of 5.067% efficiency.