• 한국재료학회지
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• 제25권2호
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• pp.107-112
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• 2015

The oxide films formed on etched aluminum foils play an important role as dielectric layers in aluminum electrolytic capacitors. $Y_2O_3$-doped $ZrO_2$ (YZ) films were coated on the etched aluminum foils by sol-gel dip coating, and the electrical properties of YZ-coated Al foils were characterized. YZ films annealed at $450^{\circ}C$ were crystallized into a cubic phase, and as the $Y_2O_3$ doping content increased, the unit cell of $ZrO_2$ expanded and the grain size decreased. The etch pits of Al foils were filled by YZ sol when it dried at atmospheric pressure after repeating for several times, but this step could essentially be avoided when being dried in a vacuum. YZ-coated foils indicated that the specific capacitance and dissipation factor were $2-2.5{\mu}F/cm^2$ and 2-4 at 1 kHz, respectively, and the leakage current and withstanding voltage of films approximately 200 nm thick were $5{\times}10^{-4}A$ at 21 V and 22 V, respectively. After being anodized at 500 V, the foils exhibited a specific capacitance and dissipation factor of $0.6-0.7{\mu}F/cm^2$ and 0.1-0.2, respectively, at 1 kHz, while the leakage current and withstanding voltage were $2{\times}10^{-4}-3{\times}10^{-5}A$ at 400 V and 420-450 V, respectively. This suggests that YZ film is a promising dielectric that can be used in high voltage Al electrolytic capacitors.

• Transactions on Electrical and Electronic Materials
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• 제1권3호
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• pp.14-17
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• 2000

Giga bit dynamic random access memory(DRAM) requires the capacitor of high dielectric films. Some metal oxides films have been proposed as the dielectric material . And Pt is one of the most promising electrode materials. However very little has been done in developing the etching technologoy Pt film. Therefore, it is the first priority to develop the technology for plasma etching of Pt film. In this study, the dry etching of Pt film was investigated in Inductively Coupled Plasma(ICP) etching system with Cl$_2$/Ar and HBr/Cl$_2$/Ar gas mixing. X-ray photoelectron spectroscopy (XPS) was used in analysis of sidewall residues for the understanding of etching mechanism. We found the etch residues on the pattern sidewall is mainly Pt-Pt, Pt-Cl and Pt-Br compounds, Etch profile was observed by Scanning Electron Spectroscopy(SEM) . The etch rate of Pt film at 10%, Cl$_2$/90% Ar gas mixing ration was higher than at 100%. Ar. Addition of HBr to Cl$_2$/Ar as an etching gas led to generally higher selectivity to SiO$_2$. And the etch residues were reduced at 5% HBr/5% Cl$_2$/90% Ar gas mixing ration. These pages provide you with an examples of the layout and style which we wish you to adopt during the preparation of your paper, Make the width of abstract to be 14cm.

• 한국정보통신학회논문지
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• 제6권5호
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• pp.696-702
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• 2002

RF magnetron reactive sputtering 법으로 BST(Bal-xSrxTiO$_3$)(50/50) 박막을 제작하여, 박막의 결정화 특성 및 표면상태와 함께 박막의 두께에 따른 전기적 특성을 조사하였다. XRD와 AFM을 이용하여 BST 박막의 결정화 특성과 표면상태를 관찰한 결과, 80$0^{\circ}C$ 에서 2분간 후열처리한 박막은 완전한 perovskite 구조를 가지며 표면거칠기도 16.1$\AA$으로 양호한 값을 나타내었다. 박막의 두께가 80nm에서 240nm으로 증가함에 따라 10KHz에서 비유전률은 199에서 265로 증가하였고, 250㎸/cm의 전기장에서 누설 전류밀도는 $0.779 {\mu}m/{cm^2}에서 0.184 {\mu}A/{cm^2}$으로 감소하였다. 두께 240nm인 BST 박막의 경우, 5V에서의 전하축적 밀도와 누설전류밀도는 각각 50.5 $fC/{{\mu}m^2} 와 0.182 {\mu}A/{cm^2}$로, 이는 DRAM의 캐패시터 절연막 응용에 매우 유망한 물질임을 나타내는 결과이다.

• 센서학회지
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• 제31권5호
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• pp.318-323
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• 2022

Barium titanate (BaTiO₃) is considered to be a beneficial ceramic material for multilayer ceramic capacitor (MLCC) applications because of its high dielectric constant and low dielectric loss. Numerous attempts have been made to improve the physical properties of BaTiO₃ in response to recent market trends by employing multicomponent alloying strategies. However, owing to its significant number of atomic combinations and unpredictable physical properties, finding a traditional experimental approach to develop multicomponent systems is difficult; the development of such systems is also time-consuming. In this study, 168 new structures were fabricated using special quasi-random structures (SQSs) of Ba_1-xCa_xTi_1-yZryO₃, and 1680 physical properties were extracted from first-principles calculations. In addition, we built an integrated database to manage the computational results, and will provide big data solutions by performing data analysis combined with AI modeling. We believe that our research will enable the global materials market to realize digital transformation through datalization and intelligence of the material development process.

• 비파괴검사학회지
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• 제21권6호
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• pp.618-629
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• 2001

본 논문은 고압 커패시터의 고장분석과 신뢰성 예측 결과를 다루고 있다. 부품의 수명과 고장률을 예측하기 위해서 두 가지 방법으로 고장 모드와 고장 메커니즘을 연구하였다 에폭시 수지로 성형된 고압 커패시터가 절연내압 시험 하에서 저항이 제로로 되는 고장에 대하여, 근본원인 고장분석 체계를 효과적으로 수립함으로써 고장 메커니즘의 원인을 분석하였다. 특히 세라믹-에폭시 계면에서의 절연파괴 고장 현상이 강조되었으며, 본 연구에서 얻어진 결과의 타당성은 마그네트론에 장착된 고압 커패시터의 열사이클 시험 수행에 의한 가속시험 결과로부터 입증되었다. 시험 결과들은 결함이 있는 로트를 신속히 규명하고 $B_{10}$ 수명을 결정하는데 유용하게 사용할 수 있다. 또한, 유전체의 절연파괴에 대해서 부하-강도 간섭모델을 이용하여 고장률을 예측하였다.

• Advances in materials Research
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• 제1권2호
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• pp.115-128
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• 2012

The structural and electrical properties of $(1-x)Ba(Sm_{1/2}Nb_{1/2})O_3-xBaTiO_3$; ($0{\leq}x{\leq}1$) ceramics were prepared by conventional ceramic technique at $1375^{\circ}C$/7 h in air atmosphere. The crystal symmetry, space group and unit cell dimensions were derived from the X-ray diffraction (XRD) data using FullProf software whereas crystallite size and lattice strain were estimated from Williamson-Hall approach. XRD analysis of the compound indicated the formation of a single-phase cubic structure with the space group Pm m. Dielectric study revealed that the compound $0.75Ba(Sm_{1/2}Nb_{1/2})O_3-0.25BaTiO_3$ is having low and ${\varepsilon}^{\prime}$ and ${\varepsilon}^{{\prime}{\prime}}$ a low $T_{CC}$ (< 5%) in the working temperature range (up to+$100^{\circ}C$) which makes this composition suitable for capacitor application and may be designated as 'Stable Low-K' Class I material as per the specifications of the Electronic Industries Association. The correlated barrier hopping model was employed to successfully explain the mechanism of charge transport in the system. The ac conductivity data were used to evaluate the density of states at Fermi level, minimum hopping length and apparent activation energy of the compounds.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.179-179
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• 2009

This is for the electrical characterization by IDC pattern using BST$(Ba_{0.5}Sr_{0.5}TiO_3)$ thin film. BST materials had been chosen for high frequency applications due to it's high permitivity and tunability. The BST thin films have been deposited on $Al_2O_3$ Substrates by Nd-YAG pulsed laser deposition with a 355nm wavelength at $700\;^{\circ}C$. The post deposition annealing at $750^{\circ}C$ in flowing $O_2$ atmosphere for 1 hours. The capacitance of IDC patterns have been measured from 1 to 10 GHz as a function of electric field ($\pm40$ KV/cm) at room temperature using inter-digital Au electrodes deposited on top of BST. The IDC patterns have three type of fingers number. For the 10 pairs finger was the best capacitance onto $Al_2O_3$ substrate. The capacitance was 0.9pF. Also Dielectric constant was been 351 at 100 mTorr and annealing temperature $750^{\circ}C$ for 1 hour. The loss tangent was been 0.00531.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권4호
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• pp.159-163
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• 2003

ln this work, we studied electrical characteristics and leakage current mechanism of $Ta_2O_{5}$ MOS(Metal-Oxide-Semiconductor) devices. $Ta_2O_{5}$ thin film (63 nm) was deposited by ALD(Atomic Layer Deposition) method at temperature of 235 $^{\circ}C$. The structures of the $Ta_2O_{5}$ thin films were examined by XRD(X-Ray Diffraction). From XRD, it is found that the structure of $Ta_2O_{5}$ is single phase and orthorhombic. From capacitance-voltage (C-V) anaysis, the dielectric constant was 19.4. The temperature dependence of current density-electric field (J-E) characteristics of $Ta_2O_{5}$ thin film was studied at temperature range of 300 - 423 K. In ohmic region (<0.5 MV/cm), the resistivity was 2.456${\times}10^{14}$ ($\omega{\cdot}cm$ at 348 K. The Schottky emission is dominant at lower temperature range from 300 to 323 K and Poole-Frenkel emission is dominant at higher temperature range from 348 to 423 K.

• 마이크로전자및패키징학회지
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• 제11권3호
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• pp.63-70
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• 2004

The structural, electrical properties of $(Ba, Sr)TiO_3[BSTO]/RuO_2$ thin films were examined by the addition of amorphous BSTO layer between crystlline BSTO film and $RuO_2$ substrate. We prepared BSTO films with double-layered structure, that is, amorphous layers deposited at $60^{\circ}C$ and crystalline films. Crystalline films were prepared at 550 on amorphous BSTO layer. The thickness of the amorphous layers was varied from 0 to 170 nm. During the deposition of crystalline films, the crystallization of the amorphous layers occurred and the structure was changed to circular while crystalline BSTO films showed columnar structure. Due to insufficient annealing effect, amorphous BSTO phase was observed when the thickness of the amorphous layers exceeded 30 nm. Amorphous BSTO layer could also prevent the formation of oxygen deficient region in $RuO_2$ surface. Leakage current of total BSTO films decreased with increasing amorphous layer thickness due to structural modifications. Dielectric constant showed maxi-mum value of 343 when amorphous layer thickness was 30 nm at which the improvement by grain growth and the degradation by amorphous phase were balanced.

• The Korean Journal of Ceramics
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• 제1권1호
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• pp.7-12
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• 1995

When a $Ta_O_5$ dielectric film is deposited on a bare silicon, the growth of $SiO_2$ at the $Ta_O_5$/Si interface cannot be avoided. Even though the $SiO_2$ layer is ultrathin (a few nm), it has great effects on the electrical properties of the capacitor. The concentration depth profiles of the ultrathin interfacial $SiO_2$ and $SiO_2/Si_3N_4$ layers were obtained using an Auger electron spectroscopy (AES) equipped with a cylindrical mirror analyzer (CMA). These AES depth profiles were quantitatively analyzed by comparing with the theoretical depth profiles which were obtained by considering the inelastic mean free path of Auger electrons and the angular acceptance function of CMA. The direct measurement of the interfacial layer thicknesses by using a high resolution cross-sectional TEM confirmed the accuracy of the AES depth analysis. The $SiO_2/Si_3N_4$ double layers, which were not distinguishable from each other under the TEM observation, could be effectively analyzed by the AES depth profiling technique.